Antimicrobial resistance in pathogens has greatly increased of late and now pose a serious public health problem globally. New antimicrobials are continuously needed to inhibit the growth of these resistant strains.
The aim of this study was to isolate and screen soil actinomycetes and evaluate their secondary metabolites for antimicrobial activities against selected pathogenic bacteria and fungi.
Testing the ability against Bacillus cereus of actinobacteria strains isolate...Agriculture Journal IJOEAR
This study aimed to test the antibacterial activity of Bacillus cereus of actinobacterial isolates isolated from marine sponges in the Kien Giang Sea, Vietnam. That can select the strains with high resistance to identify them. There were 198 actinobacterial isolates tested. Based on the ability of antimicrobial activity to B. cereus, 82/198 had the against B. cereus, in which there were six isolates with high (7.3%), 52 medium (25.6%), and 21 weak resistance (67.1%). Selection of six isolates with the best resistance to B. cereus (ND1.7a, ND2.7c, HD1-3e, HD1-6a, HD2.3b, and H6b) identified by PCR and 16S rRNA gene sequencing. The results identified five strains of Streptomyces (Streptomyces tateyamensis ND1.7a, Streptomyces althioticus HD1.3e, Streptomyces flaveolus HD1.6a, Streptomyces olivaceus HD2.3d, and Streptomyces albidoflavus H6b) and one strain of genus Microbacterium (Microbacterium tumbae ND2.7c).
Degradation of Nevirapine and Trimethoprim from Aqueous Solutions using Selec...Agriculture Journal IJOEAR
Together with pharmaceutical residues, personal care products encompassing prescription drugs, fragrances, and cosmetics have been detected in groundwater and other aquatic environments, hence compromising the quality of water. Their classification as micropollutants is due to their antibacterial resistance potential, persistence, and ecotoxicity. Biodegradation has been identified as a potential mechanism in their removal. The focus of this study focus was bioaugmentation; (Bacillus subtilis, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeroginosa) to enhance the degradation of Nevirapine and Trimethoprim in model aqueous solutions. A liquid chromatography-tandem mass spectrometer (LC-MS/MS) was used to determine the pharmaceuticals. The efficacy of the bacterial strains to degrade selected drugs was evaluated by making the two drugs the sole source of energy and carbon. From the experimental data, the highest percentage biodegradation was recorded; Pseudomonas aeroginosa (86 %) and Staphylococcus aureus (79 %) for TMP and NVP respectively.
Isolation, identification of antagonistic rhizobacterial strains obtained fro...Shazia Shahzaman
Plant growth promoting rhizobacteria (PGPR), are associated with roots, found in the rhizosphere and can directly or indirectly enhance the plant growth. In this study soil was collected from rhizosphere of chickpea fields of different areas of Rawalpindi division of Pakistan. PGPR were isolated, screened and characterized. Eight isolates of rhizobacteria (RHA, RPG, RFJ, RC, RTR, RT and RK) were isolated from Rawalpindi division and were characterized. The antagonistic activity of these PGPR isolates against root infecting fungi (Fusarium oxysporum and Verticillium spp.,) was done and production of indole acetic acid (IAA), siderophore and P-solubilization was evaluated. The isolates RHA, RPG, RFJ, RC, RRD and RT were found to be positive in producing siderophore, IAA and P-solubilization. Furthermore, most of the isolates showed antifungal activity against Fusarium oxysporum, and Verticillium spp. The rhizobacterial isolates RHA, RPG, RFJ, RC, RRD, RTR, RT and RK were used as bio-inoculants that might be beneficial for chickpea cultivation as the rhizobacterial isolates possessed the plant growth promoting characters i.e. siderophore, IAA production, phosphate solubilization. In in vitro tests, Pseudomonas sp. and Bacillus spp. inhibited the mycelial growth of the fungal root pathogens. The isolates (RHA and RPG) also significantly increased (60-70%) seed germination, shoot length, root length of the chickpea. The incidence of fungi was reduced by the colonization of RHA and RPG which enhanced the seedling vigor index and seed germination. The observations revealed that isolates RHA and RPG is quite effective to reduce the fungal root infection in greenhouse, and also increases seed yields significantly. These rhizobacterial isolates appear to be efficient yield increasing as well as effective biocontrol agent against fungal root pathogen.
Pesticidal efficacy of crude aqueous extracts of Tephrosia vogelii L., Alli...researchagriculture
Cabbage aphid (
Brevicoryne brassicae
L.) is one of the most problematic
pests in smallholder vegetable production, causing significant yield losses in heavy
infestations. Current control strategy focuses on use of synthetic pesticides that
consequently lead to decimation of natural enemies, development of insect
resistance and resurgence and upset biodiversity. Botanical pesticides have been used
widely in smallholder farmers but not much documented literature exists on efficacy
of these products. A field trial was done to assess the efficacy of crude aqueous
extracts of
Tephrosia vogelii
,
Allium sativum
and
Solanum incanum
in controlling
Brevicoryne brassicae
in
Brassica napus
production. The trial was laid in a randomized
complete block design (RCBD) with five treatments replicated four times. The five
treatments used in the experiment were
T
.
vogelii
,
A
.
sativum
,
S
.
incanum
,
dimethoate and control. Wingless adult female aphids were inoculated three weeks
after transplanting of seedlings. Spraying and data collection were done weekly for
four weeks. Data was collected on aphid nymph and adult counts on the third leaf
from the aerial plant part of randomly selected plants from each treatment for
24 hours after the application of treatments and total plant fresh weight per each
treatment. There were significant differences (p<0.05)><0.05) on the yield of rape. It was concluded that
T. vogelii
,
S
.
incanum
and
A
.
sativum
aqueous crude extracts have some pesticidal
effects on aphid in rape
production.
Pesticidal efficacy of crude aqueous extracts of Tephrosia vogelii L., Allium...researchagriculture
Cabbage aphid (Brevicoryne brassicae L.) is one of the most problematic pests in smallholder vegetable production, causing significant yield losses in heavy infestations. Current control strategy focuses on use of synthetic pesticides that consequently lead to decimation of natural enemies, development of insect resistance and resurgence and upset biodiversity. Botanical pesticides have been used widely in smallholder farmers but not much documented literature exists on efficacy of these products. A field trial was done to assess the efficacy of crude aqueous extracts of Tephrosia vogelii, Allium sativum and Solanum incanum in controlling Brevicoryne brassicae in Brassica napus production. The trial was laid in a randomized complete block design (RCBD) with five treatments replicated four times. The five treatments used in the experiment were T. vogelii, A. sativum, S. incanum, dimethoate and control. Wingless adult female aphids were inoculated three weeks after transplanting of seedlings. Spraying and data collection were done weekly for four weeks. Data was collected on aphid nymph and adult counts on the third leaf from the aerial plant part of randomly selected plants from each treatment for 24 hours after the application of treatments and total plant fresh weight per each treatment. There were significant differences (p<0.05)><0.05) on the yield of rape. It was concluded that T. vogelii, S. incanum and A. sativum aqueous crude extracts have some pesticidal effects on aphid in rape production.
Article Citation:
Shepherd Mudzingwa, Simbarashe Muzemu and James Chitamba.
Pesticidal efficacy of crude aqueous extracts of Tephrosia vogelii L., Allium sativum L. and Solanum incanum L. in controlling aphids (Brevicoryne brassicae L.) in rape (Brassica napus L.)
Journal of Research in Agriculture (2013) 2(1): 157-163.
Full Text:
http://www.jagri.info/documents/AG0040.pdf
Mass Production of Paecilomyces Lilacinus by using Different Cultivation Medi...Agriculture Journal IJOEAR
Paecilomyces lilacinus is a common saprophytic, filamentous fungus. Morphological characters of Paecilomyces lilacinus were separate mycelium, hyaline, conidia white to pink colored and formation of phialides. The growth of Paecilomyces lilacinus carried out on SDA media at room temperature was better than incubator. Various solid substrates like Rice, Wheat bran, and Sorghum were evaluated for the mass multiplication of fungus Paecilomyces lilacinus. Added dextrose and antibiotics in solid media for mass multiplication at room temperature. Among all the substrate Wheat bran recorded the maximum spore count of 7. 1 10-8 spore/ml followed by Sorghum 5. 4 10-8 spore/ml and Rice 5. 1 10-8 spore/ml after 20 days. Also dry mycelia weight or biomass of fungus Paecilomyces lilacinus without an incubator was more than using an incubator.
— Post-harvest diseases are a major problem for banana yield. Despite treatments with chemical fungicides, a persistence of diseases is noticed. This study aims at proposing a biological control method against banana post-harvest diseases by using banana rachis leachate. The effect of leachate has been tested in vitro on mycelial growth, conidial germination and in vivo on pathogenic fungi virulence. All leachate concentrations (5, 15 and 20%) tested showed antifungal activity on the tested fungi. However, the 20% concentration was more effective with complete inhibition of mycelial growth and conidial germination of all fungi. No symptoms of crown rot and anthracnose were observed after treatment of bananas with leachate. However, with azoxystrobin, the prevalence of crown rot and anthracnose was 60% and 30%, respectively. Banana rachis leachate recorded highly significant reduction of banana finger rot prevalence compared to azoxystrobin. Banana rachis leachate have strong antifungal properties that may be useful to control banana post-harvest disease as a safe alternative option to chemical fungicides Keywords— banana; post-harvest diseases; banana rachis leachate, antifungal activity.
Testing the ability against Bacillus cereus of actinobacteria strains isolate...Agriculture Journal IJOEAR
This study aimed to test the antibacterial activity of Bacillus cereus of actinobacterial isolates isolated from marine sponges in the Kien Giang Sea, Vietnam. That can select the strains with high resistance to identify them. There were 198 actinobacterial isolates tested. Based on the ability of antimicrobial activity to B. cereus, 82/198 had the against B. cereus, in which there were six isolates with high (7.3%), 52 medium (25.6%), and 21 weak resistance (67.1%). Selection of six isolates with the best resistance to B. cereus (ND1.7a, ND2.7c, HD1-3e, HD1-6a, HD2.3b, and H6b) identified by PCR and 16S rRNA gene sequencing. The results identified five strains of Streptomyces (Streptomyces tateyamensis ND1.7a, Streptomyces althioticus HD1.3e, Streptomyces flaveolus HD1.6a, Streptomyces olivaceus HD2.3d, and Streptomyces albidoflavus H6b) and one strain of genus Microbacterium (Microbacterium tumbae ND2.7c).
Degradation of Nevirapine and Trimethoprim from Aqueous Solutions using Selec...Agriculture Journal IJOEAR
Together with pharmaceutical residues, personal care products encompassing prescription drugs, fragrances, and cosmetics have been detected in groundwater and other aquatic environments, hence compromising the quality of water. Their classification as micropollutants is due to their antibacterial resistance potential, persistence, and ecotoxicity. Biodegradation has been identified as a potential mechanism in their removal. The focus of this study focus was bioaugmentation; (Bacillus subtilis, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeroginosa) to enhance the degradation of Nevirapine and Trimethoprim in model aqueous solutions. A liquid chromatography-tandem mass spectrometer (LC-MS/MS) was used to determine the pharmaceuticals. The efficacy of the bacterial strains to degrade selected drugs was evaluated by making the two drugs the sole source of energy and carbon. From the experimental data, the highest percentage biodegradation was recorded; Pseudomonas aeroginosa (86 %) and Staphylococcus aureus (79 %) for TMP and NVP respectively.
Isolation, identification of antagonistic rhizobacterial strains obtained fro...Shazia Shahzaman
Plant growth promoting rhizobacteria (PGPR), are associated with roots, found in the rhizosphere and can directly or indirectly enhance the plant growth. In this study soil was collected from rhizosphere of chickpea fields of different areas of Rawalpindi division of Pakistan. PGPR were isolated, screened and characterized. Eight isolates of rhizobacteria (RHA, RPG, RFJ, RC, RTR, RT and RK) were isolated from Rawalpindi division and were characterized. The antagonistic activity of these PGPR isolates against root infecting fungi (Fusarium oxysporum and Verticillium spp.,) was done and production of indole acetic acid (IAA), siderophore and P-solubilization was evaluated. The isolates RHA, RPG, RFJ, RC, RRD and RT were found to be positive in producing siderophore, IAA and P-solubilization. Furthermore, most of the isolates showed antifungal activity against Fusarium oxysporum, and Verticillium spp. The rhizobacterial isolates RHA, RPG, RFJ, RC, RRD, RTR, RT and RK were used as bio-inoculants that might be beneficial for chickpea cultivation as the rhizobacterial isolates possessed the plant growth promoting characters i.e. siderophore, IAA production, phosphate solubilization. In in vitro tests, Pseudomonas sp. and Bacillus spp. inhibited the mycelial growth of the fungal root pathogens. The isolates (RHA and RPG) also significantly increased (60-70%) seed germination, shoot length, root length of the chickpea. The incidence of fungi was reduced by the colonization of RHA and RPG which enhanced the seedling vigor index and seed germination. The observations revealed that isolates RHA and RPG is quite effective to reduce the fungal root infection in greenhouse, and also increases seed yields significantly. These rhizobacterial isolates appear to be efficient yield increasing as well as effective biocontrol agent against fungal root pathogen.
Pesticidal efficacy of crude aqueous extracts of Tephrosia vogelii L., Alli...researchagriculture
Cabbage aphid (
Brevicoryne brassicae
L.) is one of the most problematic
pests in smallholder vegetable production, causing significant yield losses in heavy
infestations. Current control strategy focuses on use of synthetic pesticides that
consequently lead to decimation of natural enemies, development of insect
resistance and resurgence and upset biodiversity. Botanical pesticides have been used
widely in smallholder farmers but not much documented literature exists on efficacy
of these products. A field trial was done to assess the efficacy of crude aqueous
extracts of
Tephrosia vogelii
,
Allium sativum
and
Solanum incanum
in controlling
Brevicoryne brassicae
in
Brassica napus
production. The trial was laid in a randomized
complete block design (RCBD) with five treatments replicated four times. The five
treatments used in the experiment were
T
.
vogelii
,
A
.
sativum
,
S
.
incanum
,
dimethoate and control. Wingless adult female aphids were inoculated three weeks
after transplanting of seedlings. Spraying and data collection were done weekly for
four weeks. Data was collected on aphid nymph and adult counts on the third leaf
from the aerial plant part of randomly selected plants from each treatment for
24 hours after the application of treatments and total plant fresh weight per each
treatment. There were significant differences (p<0.05)><0.05) on the yield of rape. It was concluded that
T. vogelii
,
S
.
incanum
and
A
.
sativum
aqueous crude extracts have some pesticidal
effects on aphid in rape
production.
Pesticidal efficacy of crude aqueous extracts of Tephrosia vogelii L., Allium...researchagriculture
Cabbage aphid (Brevicoryne brassicae L.) is one of the most problematic pests in smallholder vegetable production, causing significant yield losses in heavy infestations. Current control strategy focuses on use of synthetic pesticides that consequently lead to decimation of natural enemies, development of insect resistance and resurgence and upset biodiversity. Botanical pesticides have been used widely in smallholder farmers but not much documented literature exists on efficacy of these products. A field trial was done to assess the efficacy of crude aqueous extracts of Tephrosia vogelii, Allium sativum and Solanum incanum in controlling Brevicoryne brassicae in Brassica napus production. The trial was laid in a randomized complete block design (RCBD) with five treatments replicated four times. The five treatments used in the experiment were T. vogelii, A. sativum, S. incanum, dimethoate and control. Wingless adult female aphids were inoculated three weeks after transplanting of seedlings. Spraying and data collection were done weekly for four weeks. Data was collected on aphid nymph and adult counts on the third leaf from the aerial plant part of randomly selected plants from each treatment for 24 hours after the application of treatments and total plant fresh weight per each treatment. There were significant differences (p<0.05)><0.05) on the yield of rape. It was concluded that T. vogelii, S. incanum and A. sativum aqueous crude extracts have some pesticidal effects on aphid in rape production.
Article Citation:
Shepherd Mudzingwa, Simbarashe Muzemu and James Chitamba.
Pesticidal efficacy of crude aqueous extracts of Tephrosia vogelii L., Allium sativum L. and Solanum incanum L. in controlling aphids (Brevicoryne brassicae L.) in rape (Brassica napus L.)
Journal of Research in Agriculture (2013) 2(1): 157-163.
Full Text:
http://www.jagri.info/documents/AG0040.pdf
Mass Production of Paecilomyces Lilacinus by using Different Cultivation Medi...Agriculture Journal IJOEAR
Paecilomyces lilacinus is a common saprophytic, filamentous fungus. Morphological characters of Paecilomyces lilacinus were separate mycelium, hyaline, conidia white to pink colored and formation of phialides. The growth of Paecilomyces lilacinus carried out on SDA media at room temperature was better than incubator. Various solid substrates like Rice, Wheat bran, and Sorghum were evaluated for the mass multiplication of fungus Paecilomyces lilacinus. Added dextrose and antibiotics in solid media for mass multiplication at room temperature. Among all the substrate Wheat bran recorded the maximum spore count of 7. 1 10-8 spore/ml followed by Sorghum 5. 4 10-8 spore/ml and Rice 5. 1 10-8 spore/ml after 20 days. Also dry mycelia weight or biomass of fungus Paecilomyces lilacinus without an incubator was more than using an incubator.
— Post-harvest diseases are a major problem for banana yield. Despite treatments with chemical fungicides, a persistence of diseases is noticed. This study aims at proposing a biological control method against banana post-harvest diseases by using banana rachis leachate. The effect of leachate has been tested in vitro on mycelial growth, conidial germination and in vivo on pathogenic fungi virulence. All leachate concentrations (5, 15 and 20%) tested showed antifungal activity on the tested fungi. However, the 20% concentration was more effective with complete inhibition of mycelial growth and conidial germination of all fungi. No symptoms of crown rot and anthracnose were observed after treatment of bananas with leachate. However, with azoxystrobin, the prevalence of crown rot and anthracnose was 60% and 30%, respectively. Banana rachis leachate recorded highly significant reduction of banana finger rot prevalence compared to azoxystrobin. Banana rachis leachate have strong antifungal properties that may be useful to control banana post-harvest disease as a safe alternative option to chemical fungicides Keywords— banana; post-harvest diseases; banana rachis leachate, antifungal activity.
Comparative Study on Antimicrobial Activity and Microbial Load of Alternanthe...Premier Publishers
The present study analyses the antimicrobial activity and the microbial load of an edible plant Alternanthera philoxeroides (Mart.) Griseb growing in polluted and unpolluted site. The plants were collected and tested against various Gram positive, Gram negative bacteria and fungi. Antimicrobial activity was performed with acetone, aqueous, chloroform, ethanol and petroleum ether extracts of aerial parts A. philoxeroides collected from polluted and unpolluted site that showed significant antimicrobial activity against tested bacterial and fungal organisms. The extracts were compared with standards like Amoxicillin for antibacterial activity and Ketoconazole for antifungal activity. The extracts showed remarkable antimicrobial activity as measured from the zone of inhibition and results were comparable with that of standard drugs against the organisms tested. The microbial load is also enumerated in the cooked and cooked refrigerated samples from polluted and unpolluted site. In conclusion, plant extract of A. philoxeroides collected from polluted site showed less antimicrobial activity and higher antimicrobial activity in unpolluted site. The ethanol extract showed higher activity when compared to other extracts. The microbial load is higher in cooked refrigerated sample when compared to cooked sample.
— The microbiological content of Lettuce (a vegetable), commonly vended in the Benin metropolis of Edo state were evaluated. Five vending locations were chosen for the study. Whole and soft rot samples were purchased and analysed for microbiological composition. Results showed high counts in soft rot samples in lettuce. Nutrient agar plated lettuce samples had bacterial counts in the range of 2.0x 103 to 4.7x10 7. Pseudomonas species was the dominant species found in lettuce samples. Bacillus species was isolated from one location in the lettuce samples. Mac Conkey agar plated lettuce plated had bacterial counts in the range of 2.3 x 10 3 to 5.7x 10 7. Enterobacter species, E. coli, and Klebsiella species were the dominant species isolated. Though, Proteus species was isolated from lettuce samples obtained from location five only. The study observes that consuming soft rot samples could pose a risk of introducing pathogens to the consumer due to their high microbial counts and could be detrimental to the health of the consumer.
Identification and Evaluation of Antifungal Compounds from Botanicals for th...researchagriculture
Red rot is a devastating disease in sugarcane caused by fungus,
Colletotrichum
falcatum
. In this study, eighteen different botanicals were screened for
identifying effective antifungal compound against
C.
falcatum.
Among the plants
screened, 15 per cent aqueous leaf extract of
Psoralea corylifolia
alone inhibited 100
per cent growth of both mycelium as well as spore germination under
in vitro
conditions. The extract did not exhibit any inhibitory effect to the beneficial microbes
viz.
,
Pseudomonas fluorescens
,
Bacillus megaterium
and
Gluconacetobacter
diazotrophicus
which are normally used in sugarcane. The effective plant extracts
exhibiting 100 per cent antifungal activity was subjected to TLC, HPLC and GC
-
MS
analysis to identify the bioactive antifungal compound. It revealed the
presence of
7H
-
furo [3,2
-
G] (1) benzopyran
-
7
-
one as main bioactive compound which is thought to be
the intermediate of antifungal compound, 8
–
methoxypsoralen formed during
biosynthesis.
Effect of plant growth promoting rhizobacterial (PGPR) inoculation on growth ...IJEAB
Plant Growth promoting rhizobacteria are a heterogeneous group of bacteria that can be found in the rhizosphere, at root surfaces and in association with roots. They benefit plants through Production of plant hormones, such as auxins, asymbiotic N2 fixation, solubilization of mineral phosphates, antagonism against phytopathogenic microorganisms by production of antibiotics, siderophroes, Chitinase and other nutrients ability to effectively colonize roots are responsible for plant growth promotion. An experiment was conducted in the field of National Institute of Agronomic Research of Meknes. Morocco. The experiment was a completely randomized design with six replicates. There were four treatments viz. T1: (control; N0 -PGPR), T2: (N0 +2027-2), T3: (N0 +2066-7) and T4: (N0+2025-1). The results indicated that a remarkable increase in root growth, namely length, the diameter of the rod and the total chlorophyll. A total of three different bacteria colonies were isolated and proceed with in vitro screening for plant growth promoting activities; phosphate solubilization, nitrogen fixation, indole acetic acid (IAA), ammonia production and antimicrobial enzymes (cellulose, chitinase and protease) activity. Among the three bacterial strains, all bacterial strains are able to produce ammonia, IAA production and nitrogen fixation activity, one strain phosphate solubilizing activity, two strain are able to produce cellulase syntheses, Protease activity and Chitinase activity.
Secondary metabolites used to treat infections caused by microbial pathogens. It can cause illness to humans and animals. This study was carried out to screen for potential antimicrobial producing microbes from soil samples collected from different area of Garhwal region in Uttarakhand, India. Dermatophytes are a major group of closely pathogenic fungi that infect skin, hair and nails in humans and animals. In the present study, a trial was done to find out a new antimicrobial agent producing bacteria from soil samples. Antifungal activity of each bacterial isolate against dermatophytic fungus was performed with dual culture and agar well diffusion methods using SDA medium. All the isolated bacterial colonies were observed for primary screening for their anti-dermatophytic activity against the pathogenic species of dermatophytes Trichophyton (MTCC-272), Epidermophyton, (MTCC-465), Microsporum (MTCC-964), Candida albicans, and A. niger were screened by well diffusion methods. Among the total 75 bacterial isolates, only 15 of them were capable of synthesizing antimicrobial metabolites in primary screening. Out of these fifteen isolated bacterial sp. only four Bacterial colonies were found to most potent that was obtained from agricultural region of Srinagar Garhwal, in Uttarakhand found to exhibit the highest antagonistic and anti-dermatophytic activity against most of the used pathogenic dermatophytes in the study. The Physiochemical and biochemical characters of the isolated bacterial species were matched with Bacillus and Pseudomonas sp. Then antifungal activity was measured in different pH and temperature range parameter. Thus, isolated strain was given the suggested name PA-4(a), PA-2(a), PA-2 (PK-1), and PA-1(E). This study indicates that microorganisms isolated from agriculture land of Garhwal region in Uttarakhand (India) soil could be an interesting source of antimicrobial bioactive compound.
Key-words- Secondary metabolites, Antibiotic, Soil Bacteria, Dermatophytes, Antagonistic activity
“Antimicrobial activity of rhizospheric bacteria of Curcuma longa (Turmeric) ...IOSRJPBS
The present study was carried out to explore the production of antibiotics from soil microbes of medicinal Plant Curcuma longa (Turmeric). Soil samples of the Curcuma longa rhizosphere regions were collected from the different region in Akola City, Western Vidharbh region of Maharashtra. The bacterial culture from the soil samples were collected by the serial dilution and spread plate technique. The total 16 culture have been isolated from the soil samples and out of total 16 only 3 have been characterized which are potent isolates. These 3 isolates are active against the selected pathogens, E. coli, P. aeruginosa and S.aureus. These samples were labelled as S1,S2 and S3. The characterized 3 cultures were identified as Bacillus megatherium, Pseudomonas fluroscenes and Globicitella sulfidifacein by using Bergey’s manual of systemic bacteriology. The Rhizospheric bacterial crude extract of Bacillus megatherium, Pseudomonas fluorescence, Globicatella sulfidifaciens were found to be more or less active against almost all tested pathogenic strains. Hence Curcuma longa can be employed as source of natural antimicrobials that can serve as an alternative to conventional medicines.It was concluded that the best activity have been shown by the Curcuma longa rhizospheric isolates (S2) which is of Pseudomonas fluorescens against all three human pathogenic organisms (E.coli , S.aureus , P.aeroginosa ). The activity of rhizospheric isolates was showing best results against S. aureus
Effect of Agrobacterium Induced Necrosis, Antibiotic Induced Phytotoxicity an...Sandip Magdum
Agrobacterium tumefaciens infection and antibiotic wash are the critical steps of Agrobacterium mediated plant transformation procedure, most time responsible for lower transformation efficiency due to necrosis and phytotoxicity caused by biotic stress of Agrobacterium and abiotic stress by antibiotics respectively. Ammi majus Egyptian origin medicinal plant and Pearl millet cereal grain crop were studied for their stress responses to Agrobacterium mediated transformation (AMT). Agrobacterium strains LBA4404 (O.D.=0.6-0.8) and EHA105 (O.D.=0.2-0.4) were used for transformation experiments to infect calli of Ammi majus and embryogenic calli of Pearl millet respectively. Incase of antibiotic wash, Cefotaxime 500 mg L-1 was used for LBA4404 infected Ammi majus calli and Timentin 300 mg L-1 was used for EHA105 infected embryogenic calli of Pearl millet.
Effects of Agrobacterium infection, antibiotic and NaOCl washes on Agrobacterium removal and both explants physiological changes during transformation experimental procedures were studied. At the end of the experiments explants survival efficiency of Ammi majus and pearl millet were 8% and 5% respectively. Biotic and abiotic stress factors responsible for lower efficiency were investigated with various other factors and strategies were discussed which are need to be considered for higher transformation events and target tissue survival.
STUDY OF FUNGAL, BACTERIAL AND ACTINOMYCETES POPULATION IN TENDU LEAF LITTER ...Dr Dama
STUDY OF FUNGAL, BACTERIAL AND ACTINOMYCETES POPULATION IN TENDU LEAF LITTER VERMICOMPOST IN COMPARISON WITH PRESS MUDCAKE.
Mushan L.C*. Rao K.R.**, Shagalolu V.V*. and Dama L.B*@.
Bioactivity screening of Soil bacteria against human pathogenspharmaindexing
Microorganisms have a profound effect on medical science as they not only infect & cause disease but also produce metabolic products that can cure infections. Soil happens to be a source for a variety of microorganisms. Most of the bacteria, particularly actinomycetes produce biologically active secondary metabolites. Though there are a number of antibiotics available, there is a pressing need for the discovery of new source for antimicrobials against the pathogens due to the development of drug resistance of the pathogenic microorganisms. In addition to, new pathogenic strains are also developing and causing infection to human beings. Bioactive compounds are compounds that are produced by any living organism and are known to exhibit various biological activities both in-vitro & in-vivo. Bioactivity may be antimicrobial, antineoplastic, anticancerous, immunomodulation, antifertility & others. Soil bacteria were isolated by standard technique and by making use of selective media. The isolates were identified and subjected for preliminary screening to look for their ability to produce bioactive materials. A total of 96 strains were isolated from three different soil samples. 14 of them were found to have antibacterial activity against the human pathogens like Staphylococcus aureus, Streptococcus faecalis, E.coli, Klebsiella aerogenes, Proteus vulgaris, Pseudomonas aureginosa and Salmonella typhi by preliminary screening. Further the selected (3) bacteria were grown in the suitable culture media for the production of bioactive metabolites by using rotary shake flask. The active metabolites was isolated by solvent extraction and concentrated by evaporation under reduced pressure. The antimicrobial screening of the active metabolites showed prominent effect against the clinical pathogens under the study.
Optimization of antibiotic activity of composites of ethanolic extracts of fl...Agriculture Journal IJOEAR
The generation of pathogenic microorgannisms is overwhelming the potency, safety and cost of synthetic antibiotics. The study south insight for the use of plant materials to fight microbes and optimized antibiotic activity of pure, binary and ternary blends of ethanol extracts of flower of Mangifera india, Gongronema latifolium leaves, Citrus sinensis peel on Streptococcus aureus using the Simplex Lattice {3,3} mixture experimental design of the response surface methodology (RSM). Fourteen (14) blends of the plants' parts were produced and tested on the S. aureus. Inhibition zones inhibited by the extract blends ranged between 11-19 mm. Blends C and BC exhibited the highest value of 19 mm. Other blends equally exhibited some inhibition effects on the growth of the test microorganism, however, decreasing in values as their proportions in the blends carried. ANOVA on the data revealed that the model of the experiment was significant (p<0.05; R 2 =0.8350), the pure; A, B, C, and the ternary blends, ABC, were significant in the model (p<0.05). Although other blends were n ot statistically significant (p>0.05), the graphic and the equation indicated their positive contributions to the model. The model showed overall mean inhibition zone of 14.11 mm compared to 22.5 mm observed in Levofloxacin on the test organism. The study showed that ethanolic extracts of the plants' parts could provide the basis for engineering and synthesis of potent antibiotics.
Comparative Study on Antimicrobial Activity and Microbial Load of Alternanthe...Premier Publishers
The present study analyses the antimicrobial activity and the microbial load of an edible plant Alternanthera philoxeroides (Mart.) Griseb growing in polluted and unpolluted site. The plants were collected and tested against various Gram positive, Gram negative bacteria and fungi. Antimicrobial activity was performed with acetone, aqueous, chloroform, ethanol and petroleum ether extracts of aerial parts A. philoxeroides collected from polluted and unpolluted site that showed significant antimicrobial activity against tested bacterial and fungal organisms. The extracts were compared with standards like Amoxicillin for antibacterial activity and Ketoconazole for antifungal activity. The extracts showed remarkable antimicrobial activity as measured from the zone of inhibition and results were comparable with that of standard drugs against the organisms tested. The microbial load is also enumerated in the cooked and cooked refrigerated samples from polluted and unpolluted site. In conclusion, plant extract of A. philoxeroides collected from polluted site showed less antimicrobial activity and higher antimicrobial activity in unpolluted site. The ethanol extract showed higher activity when compared to other extracts. The microbial load is higher in cooked refrigerated sample when compared to cooked sample.
— The microbiological content of Lettuce (a vegetable), commonly vended in the Benin metropolis of Edo state were evaluated. Five vending locations were chosen for the study. Whole and soft rot samples were purchased and analysed for microbiological composition. Results showed high counts in soft rot samples in lettuce. Nutrient agar plated lettuce samples had bacterial counts in the range of 2.0x 103 to 4.7x10 7. Pseudomonas species was the dominant species found in lettuce samples. Bacillus species was isolated from one location in the lettuce samples. Mac Conkey agar plated lettuce plated had bacterial counts in the range of 2.3 x 10 3 to 5.7x 10 7. Enterobacter species, E. coli, and Klebsiella species were the dominant species isolated. Though, Proteus species was isolated from lettuce samples obtained from location five only. The study observes that consuming soft rot samples could pose a risk of introducing pathogens to the consumer due to their high microbial counts and could be detrimental to the health of the consumer.
Identification and Evaluation of Antifungal Compounds from Botanicals for th...researchagriculture
Red rot is a devastating disease in sugarcane caused by fungus,
Colletotrichum
falcatum
. In this study, eighteen different botanicals were screened for
identifying effective antifungal compound against
C.
falcatum.
Among the plants
screened, 15 per cent aqueous leaf extract of
Psoralea corylifolia
alone inhibited 100
per cent growth of both mycelium as well as spore germination under
in vitro
conditions. The extract did not exhibit any inhibitory effect to the beneficial microbes
viz.
,
Pseudomonas fluorescens
,
Bacillus megaterium
and
Gluconacetobacter
diazotrophicus
which are normally used in sugarcane. The effective plant extracts
exhibiting 100 per cent antifungal activity was subjected to TLC, HPLC and GC
-
MS
analysis to identify the bioactive antifungal compound. It revealed the
presence of
7H
-
furo [3,2
-
G] (1) benzopyran
-
7
-
one as main bioactive compound which is thought to be
the intermediate of antifungal compound, 8
–
methoxypsoralen formed during
biosynthesis.
Effect of plant growth promoting rhizobacterial (PGPR) inoculation on growth ...IJEAB
Plant Growth promoting rhizobacteria are a heterogeneous group of bacteria that can be found in the rhizosphere, at root surfaces and in association with roots. They benefit plants through Production of plant hormones, such as auxins, asymbiotic N2 fixation, solubilization of mineral phosphates, antagonism against phytopathogenic microorganisms by production of antibiotics, siderophroes, Chitinase and other nutrients ability to effectively colonize roots are responsible for plant growth promotion. An experiment was conducted in the field of National Institute of Agronomic Research of Meknes. Morocco. The experiment was a completely randomized design with six replicates. There were four treatments viz. T1: (control; N0 -PGPR), T2: (N0 +2027-2), T3: (N0 +2066-7) and T4: (N0+2025-1). The results indicated that a remarkable increase in root growth, namely length, the diameter of the rod and the total chlorophyll. A total of three different bacteria colonies were isolated and proceed with in vitro screening for plant growth promoting activities; phosphate solubilization, nitrogen fixation, indole acetic acid (IAA), ammonia production and antimicrobial enzymes (cellulose, chitinase and protease) activity. Among the three bacterial strains, all bacterial strains are able to produce ammonia, IAA production and nitrogen fixation activity, one strain phosphate solubilizing activity, two strain are able to produce cellulase syntheses, Protease activity and Chitinase activity.
Secondary metabolites used to treat infections caused by microbial pathogens. It can cause illness to humans and animals. This study was carried out to screen for potential antimicrobial producing microbes from soil samples collected from different area of Garhwal region in Uttarakhand, India. Dermatophytes are a major group of closely pathogenic fungi that infect skin, hair and nails in humans and animals. In the present study, a trial was done to find out a new antimicrobial agent producing bacteria from soil samples. Antifungal activity of each bacterial isolate against dermatophytic fungus was performed with dual culture and agar well diffusion methods using SDA medium. All the isolated bacterial colonies were observed for primary screening for their anti-dermatophytic activity against the pathogenic species of dermatophytes Trichophyton (MTCC-272), Epidermophyton, (MTCC-465), Microsporum (MTCC-964), Candida albicans, and A. niger were screened by well diffusion methods. Among the total 75 bacterial isolates, only 15 of them were capable of synthesizing antimicrobial metabolites in primary screening. Out of these fifteen isolated bacterial sp. only four Bacterial colonies were found to most potent that was obtained from agricultural region of Srinagar Garhwal, in Uttarakhand found to exhibit the highest antagonistic and anti-dermatophytic activity against most of the used pathogenic dermatophytes in the study. The Physiochemical and biochemical characters of the isolated bacterial species were matched with Bacillus and Pseudomonas sp. Then antifungal activity was measured in different pH and temperature range parameter. Thus, isolated strain was given the suggested name PA-4(a), PA-2(a), PA-2 (PK-1), and PA-1(E). This study indicates that microorganisms isolated from agriculture land of Garhwal region in Uttarakhand (India) soil could be an interesting source of antimicrobial bioactive compound.
Key-words- Secondary metabolites, Antibiotic, Soil Bacteria, Dermatophytes, Antagonistic activity
“Antimicrobial activity of rhizospheric bacteria of Curcuma longa (Turmeric) ...IOSRJPBS
The present study was carried out to explore the production of antibiotics from soil microbes of medicinal Plant Curcuma longa (Turmeric). Soil samples of the Curcuma longa rhizosphere regions were collected from the different region in Akola City, Western Vidharbh region of Maharashtra. The bacterial culture from the soil samples were collected by the serial dilution and spread plate technique. The total 16 culture have been isolated from the soil samples and out of total 16 only 3 have been characterized which are potent isolates. These 3 isolates are active against the selected pathogens, E. coli, P. aeruginosa and S.aureus. These samples were labelled as S1,S2 and S3. The characterized 3 cultures were identified as Bacillus megatherium, Pseudomonas fluroscenes and Globicitella sulfidifacein by using Bergey’s manual of systemic bacteriology. The Rhizospheric bacterial crude extract of Bacillus megatherium, Pseudomonas fluorescence, Globicatella sulfidifaciens were found to be more or less active against almost all tested pathogenic strains. Hence Curcuma longa can be employed as source of natural antimicrobials that can serve as an alternative to conventional medicines.It was concluded that the best activity have been shown by the Curcuma longa rhizospheric isolates (S2) which is of Pseudomonas fluorescens against all three human pathogenic organisms (E.coli , S.aureus , P.aeroginosa ). The activity of rhizospheric isolates was showing best results against S. aureus
Effect of Agrobacterium Induced Necrosis, Antibiotic Induced Phytotoxicity an...Sandip Magdum
Agrobacterium tumefaciens infection and antibiotic wash are the critical steps of Agrobacterium mediated plant transformation procedure, most time responsible for lower transformation efficiency due to necrosis and phytotoxicity caused by biotic stress of Agrobacterium and abiotic stress by antibiotics respectively. Ammi majus Egyptian origin medicinal plant and Pearl millet cereal grain crop were studied for their stress responses to Agrobacterium mediated transformation (AMT). Agrobacterium strains LBA4404 (O.D.=0.6-0.8) and EHA105 (O.D.=0.2-0.4) were used for transformation experiments to infect calli of Ammi majus and embryogenic calli of Pearl millet respectively. Incase of antibiotic wash, Cefotaxime 500 mg L-1 was used for LBA4404 infected Ammi majus calli and Timentin 300 mg L-1 was used for EHA105 infected embryogenic calli of Pearl millet.
Effects of Agrobacterium infection, antibiotic and NaOCl washes on Agrobacterium removal and both explants physiological changes during transformation experimental procedures were studied. At the end of the experiments explants survival efficiency of Ammi majus and pearl millet were 8% and 5% respectively. Biotic and abiotic stress factors responsible for lower efficiency were investigated with various other factors and strategies were discussed which are need to be considered for higher transformation events and target tissue survival.
STUDY OF FUNGAL, BACTERIAL AND ACTINOMYCETES POPULATION IN TENDU LEAF LITTER ...Dr Dama
STUDY OF FUNGAL, BACTERIAL AND ACTINOMYCETES POPULATION IN TENDU LEAF LITTER VERMICOMPOST IN COMPARISON WITH PRESS MUDCAKE.
Mushan L.C*. Rao K.R.**, Shagalolu V.V*. and Dama L.B*@.
Bioactivity screening of Soil bacteria against human pathogenspharmaindexing
Microorganisms have a profound effect on medical science as they not only infect & cause disease but also produce metabolic products that can cure infections. Soil happens to be a source for a variety of microorganisms. Most of the bacteria, particularly actinomycetes produce biologically active secondary metabolites. Though there are a number of antibiotics available, there is a pressing need for the discovery of new source for antimicrobials against the pathogens due to the development of drug resistance of the pathogenic microorganisms. In addition to, new pathogenic strains are also developing and causing infection to human beings. Bioactive compounds are compounds that are produced by any living organism and are known to exhibit various biological activities both in-vitro & in-vivo. Bioactivity may be antimicrobial, antineoplastic, anticancerous, immunomodulation, antifertility & others. Soil bacteria were isolated by standard technique and by making use of selective media. The isolates were identified and subjected for preliminary screening to look for their ability to produce bioactive materials. A total of 96 strains were isolated from three different soil samples. 14 of them were found to have antibacterial activity against the human pathogens like Staphylococcus aureus, Streptococcus faecalis, E.coli, Klebsiella aerogenes, Proteus vulgaris, Pseudomonas aureginosa and Salmonella typhi by preliminary screening. Further the selected (3) bacteria were grown in the suitable culture media for the production of bioactive metabolites by using rotary shake flask. The active metabolites was isolated by solvent extraction and concentrated by evaporation under reduced pressure. The antimicrobial screening of the active metabolites showed prominent effect against the clinical pathogens under the study.
Optimization of antibiotic activity of composites of ethanolic extracts of fl...Agriculture Journal IJOEAR
The generation of pathogenic microorgannisms is overwhelming the potency, safety and cost of synthetic antibiotics. The study south insight for the use of plant materials to fight microbes and optimized antibiotic activity of pure, binary and ternary blends of ethanol extracts of flower of Mangifera india, Gongronema latifolium leaves, Citrus sinensis peel on Streptococcus aureus using the Simplex Lattice {3,3} mixture experimental design of the response surface methodology (RSM). Fourteen (14) blends of the plants' parts were produced and tested on the S. aureus. Inhibition zones inhibited by the extract blends ranged between 11-19 mm. Blends C and BC exhibited the highest value of 19 mm. Other blends equally exhibited some inhibition effects on the growth of the test microorganism, however, decreasing in values as their proportions in the blends carried. ANOVA on the data revealed that the model of the experiment was significant (p<0.05; R 2 =0.8350), the pure; A, B, C, and the ternary blends, ABC, were significant in the model (p<0.05). Although other blends were n ot statistically significant (p>0.05), the graphic and the equation indicated their positive contributions to the model. The model showed overall mean inhibition zone of 14.11 mm compared to 22.5 mm observed in Levofloxacin on the test organism. The study showed that ethanolic extracts of the plants' parts could provide the basis for engineering and synthesis of potent antibiotics.
Protein was extracted from muscles of Channa striatus and attempts were
made to evaluate in vitro antibacterial activity against clinical bacterial isolates. The
higher concentration of protein (100μg/ml) extracts exhibited a pronounced activity
against Pseudomonas aeruginosa (21 mm), Proteus vulgaris (19 mm), Citrobacter sp
(19 mm), Klebsiella pneumoniae (18 mm), Micrococcus sp (17 mm), Bacillus subtilis (16
mm), Staphylococcus aureus (15 mm), E. coli (14 mm) and Serratia marcescens (5
mm). The minimum inhibitory concentration and minimum bactericidal concentration
were found to be 20-40 μg/ml and 80-100 μg/ml respectively for the extracts of
Channa striatus protein against test organisms. This study confirms that C. striatus fish
protein extracts possess antibacterial activity against a wide range of microbes and
justified that it could be used in the traditional medicine as a remedy for the
treatment of bacterial diseases.
The study was carried out with the aim of sourcing for bacteria from the natural environment having antifungal capabilities to control and inhibit postharvest fungal spoilage of fruits and vegetables caused by Botrytis cinerea. Soil and water samples were collected from Heriot Watt University environment and Dr Ruth Fowler’s garden and inoculated using the spread plate technique; identification was carried out using Microbact Identification kits; and isolates assayed for antifungal activities against Botrytis cinerea. Forty eight bacteria species were isolated out of which sixteen (16) belonging to genera Pseudomonas, Bacillus, Escherichia, Burkholderia, Staphylococcus, Streptococcus, and Proteus showed antifungal activities. Bacteria species Pseudomonas stutzeri and Burkholderia cepacia had the highest zones of inhibition with average radii of 3.06 and 3.20 cm respectively. The bacteria had the potential to inhibit mycelial and spore growth at varying levels thus making them possible candidates for further tests and studies. Considering the aim of the study, further research into identifying these antifungal isolates inhibitory compounds and metabolites is highly recommended.
Identification and evaluation of antifungal compounds from botanicals for the...researchagriculture
Red rot is a devastating disease in sugarcane caused by fungus, Colletotrichum falcatum. In this study, eighteen different botanicals were screened for identifying effective antifungal compound against C. falcatum. Among the plants screened, 15 per cent aqueous leaf extract of Psoralea corylifolia alone inhibited 100 per cent growth of both mycelium as well as spore germination under in vitro conditions. The extract did not exhibit any inhibitory effect to the beneficial microbes viz., Pseudomonas fluorescens, Bacillus megaterium and Gluconacetobacter diazotrophicus which are normally used in sugarcane. The effective plant extracts exhibiting 100 per cent antifungal activity was subjected to TLC, HPLC and GC-MS analysis to identify the bioactive antifungal compound. It revealed the presence of 7H-furo [3,2-G] (1) benzopyran-7-one as main bioactive compound which is thought to be the intermediate of antifungal compound, 8 – methoxypsoralen formed during biosynthesis.
Article Citation:
Rajkumar D and Murugesan R.
Identification and Evaluation of Antifungal Compounds from Botanicals for the Control of Sugarcane Red Rot Pathogen, Colletotrichum falcatum.
Journal of Research in Agriculture (2013) 2(1): 164-172.
Full Text:
http://www.jagri.info/documents/AG0044.pdf
Detection of Slime-Producing Staphylococcus aureus Strains Isolated from Food...Agriculture Journal IJOEAR
Abstract— The contamination of food with pathogenic microorganisms producing biofilm, implies a high cost for the food industry and represents a serious risk for the health of consumers. The antibacterial activity of organic extracts of Azorella trifurcata and Mulinum echegarayii was evaluated against 4 Staphylococcus aureus slime-producing strains isolated from bakery foods and against S. aureus ATCC 35556 slime-producing strain and S. aureus ATCC 25923 non slime-producing strain. The plant extracts showed antibacterial effectiveness against all the strains of S. aureus tested with minimum inhibitory concentration (MIC) between 500 and 8000 µg/ml. M. echegarayii 30:70% AcOEt:HEX showed the best activity: five strains of S. aureus showed MIC of 1000 μg/ml and S. aureus ATCC 25923 was inhibited at doses of 500 μg/ml. The values of minimum bactericidal concentration (MBC) of the extracts assayed were one or two times higher than corresponding MIC values. This study showed that extracts of Azorella trifurcata and Mulinum echegarayii are promising for future natural therapy against slime-producing S. aureus. Plant extracts with activity against slime producing S. aureus strains could provide benefits for of food technology and public health.
Efficacy of Microbial Biopesticide Formulations in the control of Xanthomonas...Open Access Research Paper
The cashew tree (Anacardium occidentale L.) occupies an important place in the world because of its cashew nut. However, its cultivation is confronted with bacteriosis, a bacterial disease caused by Xanthomonas citri pv. Mangiferaeindicae. This disease is one of the main causes of the low yield per hectare of cashew nuts, which fluctuates between 350 and 500 kg/ha. In view of this, it is wise to find ways of controlling this disease. It is in this context the objective of this work was to produce bio-formulations based on bacteria isolated from the rhizosphere of cashew trees, in order to evaluate their effectiveness on the growth of the agent responsible for cashew bacteriosis (Xanthomonas citri pv. Mangiferaeindicae). Thus, two liquid formulations were made from Pseudomonas fluorescens and Bacillus subtilis isolated from the rhizosphere of cashew. Stability, in vitro antagonism and biocontrol tests against Xanthomonas citri pv. Mangiferaeindicae were performed. The results obtained showed an inhibition of the Xanthomonas citri pv. Mangiferaeindicae bacterium with inhibition zones of 8.13 ± 2.1 and 25.20 ± 3.9 mm in diameter respectively for the products formulated with Bacillus subtilis and Pseudomonas fluorescens. In biocontrol tests, both formulated products showed their ability to protect cashew plants against bacterial blight with reduction rates of 80.95 ± 2.3 % and 73.80 ± 5.2% for the Pseudomonas fluorescens and Bacillus subtilis formulations, respectively. These two formulations of bacterial, once tested in cashew plantations, could be used in the biological control of cashew bacterial blight in Côte d’Ivoire.
Synergistic antibacterial effects of three edible plants extract against anti...Open Access Research Paper
In vitro synergistic antibacterial effects among Alocasia macrorrhizos rhizome, Amorphophallus paeoniifolius corm and Colocasia esculenta corm extracts were tested against six resistant bacteria viz., Yersinia enterocolitica, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Clostridium difficile and Staphylococcus aureus. The inhibition zone was compared with the commercially available antibiotic (tetracycline). High inhibitory activity was observed against E. coli (12.67±0.33 mm) and S. aureus (12.50±0.29 mm) for methanol extract at 800 mgml-1 of concentration. MIC and MBC of the extracts ranged from 200-580 mgml-1 and 250-650 mgml-1 respectively. The lowest MIC and MBC of the extracts were measured against E. coli.
Early blight of potato caused by Alternaria alternata (Fries) Keissler is one of the factors that affect
potato production. Using chemical control to reduce disease severity represent another risk for
agriculture. Biological control, using microorganisms, as well as plant extract and compost are safe
measures that give reliable control. Applying either measure of control reduced disease incidence to less
than 2% during two successive seasons. Microbial spray of diseased potato reduced the disease to various
extents. Trichoderma sp. was the most effective among all tested microorganisms, followed by
Penicillium sp. On the other hand, alcoholic extract of three plants was more effective than their water
extract. However, water extract showed highly significant reduction of disease incidence. Polygonum
gave the highest reduction of disease incidence in both cases. Also water extract of compost greatly
suppressed early blight when applied as spray to potato leaves. Duration of extraction may affect the
ability of compost extract to suppress disease. All results were comparable to that of fungicides.
International Journal of Pharmaceutical Science Invention (IJPSI)inventionjournals
is an international journal intended for professionals and researchers in all fields of Pahrmaceutical Science. IJPSI publishes research articles and reviews within the whole field Pharmacy and Pharmaceutical Science, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online
Antibacterial Activity of Stem Bark Extracts of Oroxylum indicum an Endangere...IOSR Journals
The present work has been under taken to study the antibacterial activity of stem bark extracts of O.
indicum against disease causing gram negative and gram positive bacteria. Antimicrobial activity of solvent
extracts of stem bark of Oroxylum indicum has been studied to find out its activity against four important
bacterial strains Bacillus subtilis, B. cereus, Staphylococcus albus and S. aureus . The antimicrobial activity of
the stem bark extracts was done through well diffusion method and by measuring the inhibition zone around the
disc. The results revealed that the aqueous extracts of O. indicum exhibited antimicrobial activity against all the
microbes under study. The results provided evidence that the species O. indicum can be used as a potential
source of antimicrobial agent.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
Richard's aventures in two entangled wonderlandsRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
The increased availability of biomedical data, particularly in the public domain, offers the opportunity to better understand human health and to develop effective therapeutics for a wide range of unmet medical needs. However, data scientists remain stymied by the fact that data remain hard to find and to productively reuse because data and their metadata i) are wholly inaccessible, ii) are in non-standard or incompatible representations, iii) do not conform to community standards, and iv) have unclear or highly restricted terms and conditions that preclude legitimate reuse. These limitations require a rethink on data can be made machine and AI-ready - the key motivation behind the FAIR Guiding Principles. Concurrently, while recent efforts have explored the use of deep learning to fuse disparate data into predictive models for a wide range of biomedical applications, these models often fail even when the correct answer is already known, and fail to explain individual predictions in terms that data scientists can appreciate. These limitations suggest that new methods to produce practical artificial intelligence are still needed.
In this talk, I will discuss our work in (1) building an integrative knowledge infrastructure to prepare FAIR and "AI-ready" data and services along with (2) neurosymbolic AI methods to improve the quality of predictions and to generate plausible explanations. Attention is given to standards, platforms, and methods to wrangle knowledge into simple, but effective semantic and latent representations, and to make these available into standards-compliant and discoverable interfaces that can be used in model building, validation, and explanation. Our work, and those of others in the field, creates a baseline for building trustworthy and easy to deploy AI models in biomedicine.
Bio
Dr. Michel Dumontier is the Distinguished Professor of Data Science at Maastricht University, founder and executive director of the Institute of Data Science, and co-founder of the FAIR (Findable, Accessible, Interoperable and Reusable) data principles. His research explores socio-technological approaches for responsible discovery science, which includes collaborative multi-modal knowledge graphs, privacy-preserving distributed data mining, and AI methods for drug discovery and personalized medicine. His work is supported through the Dutch National Research Agenda, the Netherlands Organisation for Scientific Research, Horizon Europe, the European Open Science Cloud, the US National Institutes of Health, and a Marie-Curie Innovative Training Network. He is the editor-in-chief for the journal Data Science and is internationally recognized for his contributions in bioinformatics, biomedical informatics, and semantic technologies including ontologies and linked data.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Multi-source connectivity as the driver of solar wind variability in the heli...
Isolation and Screening of Soil Actinomycetes for Antimicrobial Activity
1. Isolation and Screening of Soil Actinomycetes for
Antimicrobial Activity
Olakunle Ebenezer Ajibola
Department of Microbiology, Faculty of Life Sciences, University of Benin
December 2019
kunlesid@gmail.com
ABSTRACT
Antimicrobial resistance in pathogens has greatly increased of late and now pose a serious public health
problem globally. New antimicrobials are continuously needed to inhibit the growth of these resistant strains.
The aim of this study was to isolate and screen soil actinomycetes and evaluate their secondary metabolites for
antimicrobial activities against selected pathogenic bacteria and fungi.
Soil samples were collected, pre-treated with CaCO3, serially diluted and spread plated on actinomycetes
isolation agar (AIA) and international streptomyces project media 2 (ISP-2), supplemented with nystatin,
neomycin and polymyxin B . Perpendicular streak method was used to test the isolated actinomycetes for
antagonistic activities against different test microorganisms. Small scale submerged fermentation system was
used for the production of antimicrobial metabolites from the isolates. Agar well diffusion was then used to
evaluate antimicrobial activities of the crude extracts against the test microorganisms.
A total of 28 different microorganisms were isolated, characterized by cultural and morphological methods and
identified as actinomycetes. Out of the 28 isolates, 10 (36%) showed antimicrobial activities on primary
screening; from which isolates BYQ3, CYP1, CYP2, CYP4 and CYQ2 were chosen for their wide spectrum of
activities. Isolates CYP1 and CYP2 had the widest zones with CYP1 producing 26 mm against Candida
albicans. The two promising isolates were further characterized by physiological and biochemical tests and
identified as genus Streptomyces. Isolate CYP1 was then subjected to 16S rRNA gene sequence analysis which
confirmed its homology to Streptomyces albus (strain DSM 40313) of the order Actinomycetales and class
Actinobacteria. Optimization of production conditions, purification and structural characterization are
recommended to determine the quality and novelty of these antimicrobials.
Key Words: Actinomycetes, Antimicrobial, Isolation, Pathogens, Screening
INTRODUCTION
Actinomycetes are gram-positive bacteria with a G-C
content of over 55% in their genome. They belong to
the order Actinomycetales and form an important
segment of the microflora of natural environments.
Soils, manures and composts, freshwater bodies such
as lakes and river bottoms contain an abundance of
these organisms. Actinomycetes are aerobic, spore
forming organisms with a distinctive feature of
possessing filamentous hyphae that do not normally
undergo fragmentation. Due to their phenotypic
similarities to fungi, actinomycetes are also called as
ray fungi (Chaudhary et al., 2013).
Actinomycetes are excellent sources of
therapeutically important secondary metabolites such
as, antibiotics, antifungals, antivirals and anticancer
2. agents; they are also known to produce
immunosuppressants, enzymes and other industrially
useful compounds (Dhawane and Zodpe, 2017).
Some effective antibiotics manufactured from
actinomycetes include: penicillin, streptomycin,
tetracycline, erythromycin, amphotericin and
vancomycin. These natural microbial products are
notable for their impressive therapeutic activities as
well as their desirable pharmacokinetic properties
needed for clinical development (Khasabuli and
Kibera, 2014). Antibiotics produced by
actinomycetes have a broad array of chemical
structure, which include β-lactams, aminoglycosides,
antracyclines, tetracycline, nucleosides,
actinomycins, polyenes and peptides. Also,
secondary metabolites of soil actinomycetes origin
have been proven to be good inhibitors of a wide
range of plant pathogens (Agadagba, 2014).
A great variety of soil actinomycetes have been
screened in the last few decades, accounting for
about 80% of useful secondary metabolites available
for sale. It is estimated that one-third of all naturally
occurring antibiotics are from actinomycete sources
(Chaudhary et al., 2013). Two genera, Streptomyces
and Micromonospora account for more than 70% of
these antibiotics (Rai et al., 2018). The diversity of
actinomycetes in any soil environment is determined
by the soil type, organic matter content, geographical
location, farming activities, etc. (Agadagba, 2014).
Infections caused by antibiotic resistant
microorganisms have become a big healthcare
challenge in the 21st century (Jarallah and Rahaman,
2014). Antibiotics like erythromycin, penicillin, and
methicillin which were once very effective against
infectious diseases are now ineffective because many
pathogens have acquired resistance to these
antibiotics. These multidrug resistant pathogens
develop faster than the rate at which of new
antimicrobial drugs are developed (Kumar et al.,
2010).
The worldwide increase in antimicrobial resistant
strains requires that efforts be intensified towards the
discovery of new antibacterial and antifungal agents.
Hence, scientists are actively involved in isolation
and screening of actinomycetes from diverse
environments with the aim of producing new
antimicrobials to replace the existing ones.
MATERIALS AND METHODS
Sample Collection
Four soil samples were collected from four dissimilar
locations in Benin City (latitude 6.3350°N, longitude
5.6037°E), Edo State, Nigeria in June 2018. Every
sample was a mixture of soil collected from 4 to 5
holes (from the same site) whose depth was around 1
to 10 cm. Surface layer of the soil was removed and
the central portion was collected in sterile plastic
bags with the help of a trowel, previously sterilised
with ethanol. Samples were all labelled accordingly,
transported immediately to the laboratory and air
dried in laminar airflow cabinet for 24 hours at room
temperature and stored at 4°C for further
investigation.
Pre-Treatment of Soil Samples
The soil samples were pretreated with CaCO3 to
eliminate gram negative bacteria; 10 g of every
sample was taken in a mortar and triturated with 1%
CaCO3 and incubated at 30°C for 2 days in a closed
Petri dish. Water saturated filter paper was used to
maintain a high relative humidity in the Petri dish.
Nystatin was later added to the CaCO3-treated soil
cultures to suppress the growth of fungi. Portions of
each soil sample were also cultured without CaCO3
treatment and a combination of nystatin and
neomycin plus polymyxin B was used to inhibit
fungi and bacteria respectively (Wadetwar and Patil,
2013; Chaudhary et al., 2013).
Isolation of Actinomycetes
One gram each, of both the air dried and CaCO3-
treated soil samples were suspended in 100ml of
sterilised water in a flask which were rotary shaken
for 30 min at 150 rpm. From these suspensions,
dilutions were prepared as 1:10, 1:100, and 1:1000 in
distilled water. Aliquots of 0.1ml of the highest
3. dilutions were spread on the surface of two different
types of media. The different media used were
actinomycetes isolation agar (AIA) and International
Streptomyces project media 2 (ISP-2). A solution
nystatin (50µg/ml of media), prepared in ethanol and
a solution of neomycin plus polymyxin B (50µg/ml
of media) prepared in sterile distilled water were
added to the media accordingly. The plates were
incubated at 28°C for 7 days. Typical actinomycetes
colonies (tough, leathery or rough, chalky) were
selected and further isolated by streak plate
technique. Single isolated colonies were stored on
ISP 2 agar slants at 4°C until further use (Muleta and
Assefa, 2018; Njenga et al., 2017; Priyadarshini et
al., 2016; Bizuye et al., 2013).
Screening of Isolates for Antimicrobial Activity
Test Microorganisms
Microorganisms used to screen actinomycetes
isolates for antimicrobial activities were Escherichia
coli, Klebsiella pneumoniae, Pseudomonas
aeruginosa, Staphylococcus aureus, S. typhi,
Candida albicans, Mucor sp., Aspergillus niger,
Aspergillus fumigatus and Fusarium sp. The test
microorganisms were acquired from University of
Benin teaching hospital (UBTH) Microbiology
laboratory and Mycofarms Research Laboratory,
Benin City.
Primary Screening
Primary screening to assess the antimicrobial
capabilities of purified actinomycetes cultures was
done by perpendicular streak method. Each
actinomycete isolate was tested for antagonism by
making a streak of the axenic culture on nutrient agar
plate, for bacteria and sabouraud dextrose agar plate
for fungi. Incubation of the plates was done at 28◦C
for 5 days before cross streaking perpendicularly
with test microorganisms. The plates were finally
incubated at 37°C for 24 to 48 hours and 28°C for 48
to 72 hours for the bacterial and fungal test
organisms respectively. Antagonistic capabilities of
isolates were analysed by measuring the distances of
clearance. Isolates with good antagonistic activities
were taken for secondary screening (Wadetwar and
Patil, 2013; Muleta and Assefa, 2018; Bizuye et al.,
2013; Singh et al., 2016).
Metabolite Production
Isolates with promising antimicrobial abilities on
primary screening were used for bioactive
metabolites production in a small scale submerged
fermentation system. This was done by preparing a
well-sporulated 7 - 10 days culture of each isolate.
Spore suspensions were prepared by adding 10ml of
sterilised water to spores. Each suspension was added
to 100ml of potato dextrose broth (inoculum
medium) contained in a 250ml conical flask and
incubated on a rotary shaker at 210-220 rpm, 28°C
for 4 days. At the end of the inoculum incubation
period, 10ml of the incubated medium was used to
inoculate another 250ml conical flask containing
100ml of the production medium (ISP-2 broth). The
flasks were then incubated for 7 days on a rotary
shaker at 28°C. After fermentation, 10ml of each
fermented broth were harvested and spun in a
centrifuge for 15 minutes at 5000 rpm to remove the
cells from broth. The supernatant was tested for
antimicrobial activity by agar well diffusion assay
(Cavalho and Van Der Sand, 2016; Priyadarshini et
al., 2016; Singh et al., 2016; Nanjwade et al., 2010).
Agar Well Diffusion Assay
Nutrient agar and Sabouraud dextrose agar plates
were prepared and inoculated with the test
microorganisms by spread plate method. A sterile
cork borer was used to make wells on the inoculated
plates and 50μl of supernatant from the centrifuged
fermented broth deposited in each well. The culture
plates were refrigerated for 2 hours to allow the
content of the wells diffuse into the agar medium.
The plates were then incubated for 24 to 48 hours at
37°C and 48 to 72 hours at 28°C for bacteria and
fungi respectively. The inhibition zones in
4. millimetres (mm) were measured at the completion
of incubation. Actinomycetes isolates with good
inhibition activity were then selected for
morphological and molecular identification
(Chaudhary et al., 2013; Priyadarshini et al., 2016;
Jarallah and Rahaman, 2014).
Morphological Characterization
Isolates were cultured on ISP-2 media and incubated
at 28°C for 5 days. Morphological characteristics of
the resulting colonies were examined with a
magnifying lens; characteristics examined include
colour of mycelium, diffusible pigment, elevation
and the nature of colony (Njenga et al., 2017;
Chaudhary et al., 2013).
Physiological and Biochemical Characterization
After secondary antimicrobial screening, isolates
with significant antimicrobial activity were
characterised through physiological and biochemical
tests. Tests carried out include gelatin hydrolysis,
urea hydrolysis, starch hydrolysis, production of
hydrogen sulphide, motility test, citrate test, triple
sugar iron agar test (TSIA), indole test,
Voges‑Proskauer test, methyl red test, oxidase test
and catalase test (Chaudhary et al., 2013; Mohan et
al., 2014).
Molecular Identification
The actinomycetes isolate with the best
antimicrobial activity was selected for molecular
identification by 16S ribosomal RNA gene
sequencing (Priyadarshini et al., 2016).
RESULTS
Twenty-eight different actinomycetes were isolated
from four soil samples collected at a depth of 1 - 10
cm from four different locations in Benin City. Of
these 28 isolates, 7 were isolated from clayey, water
lodged soil with sparse vegetation, 6 from loamy soil
with forest canopy cover, 11 from sandy soil with
grasses cover and 4 from a refuse dump site with
sandy soil, as presented in Table 1.
Out of the 28 actinomycete isolates tested for
antagonistic activities in the primary screening
process, 10 displayed different levels of activity
against the test organisms as presented in Table 2.
Cultural and morphological characteristics of the 10
isolates, which were selected for further analysis, are
presented in Table 3
Table 1: Physico-chemical properties of soil samples collected from different sites in Benin City and their
average culturable actinomycetes counts
Values are means±SD
Sample
sites
Description of
sample area
Soil pH Soil
temperature
(°C)
Average
actinomycetes
count (CFU/g)
Number of
actinomycetes
isolates
A
Clayey, water
lodged soil with
sparse vegetation
5.74 ± 0.02 25 ± 0.5 3.0×104
± 2.4 4
B
Loamy soil with
forest canopy cover
6.21 ± 0.02 25 ± 0.5 3.3×104
± 1.2 6
C
Sandy soil with
dense grasses cover
5.65 ± 0.006 26 ± 0.5 3.6×104
± 1.9 11
D
Refuse dump site
with sandy soil
5.47 ± 0.02 26 ± 0.5 3.1×104
± 0.7 7
5. Table 2: Primary screening of actinomycetes isolates for antimicrobial activity.
+ Active against test organism; - inactive against test organism.
Table 3: Cultural characteristics of selected actinomycetes isolates on ISP-2 media
+ Diffusible pigment present; - Diffusible pigment absent.
Isolates Test microorganisms
E. coli P. aeruginosa S. aureus S. typhi C. albicans K. pneumoniae Mucor sp. A. niger A. fumigatus Fusarium sp.
AXP1 + - - + - + - - - -
BYQ3 + - + - - + + - - -
BYQ4 + + - - - + - - - -
CYP1 + - + + + + + + + +
CYP2 + + + - + + + + + +
CYP4 + - + + + + - - - -
CYQ1 - - - - + - - + + -
CYQ2 + - - + - - - + + -
CYQ7 - + - - + - - - - +
DYQ4 - - + - + - - - - -
Isolates Aerial mycelium Diffusible pigment Elevation Surface
AXP1 grey - flat smooth
BYQ3 grey - raised rough
BYQ4 grey - raised rough
CYP1 white + raised smooth
CYP2 brown + raised rough
CYP4 white + raised rough
CYQ1 grey - raised rough
CYQ2 brown + flat rough
CYQ7 black - raised smooth
DYQ4 grey - flat rough
6. As a result of primary screening, 5 isolates were
selected on the basis of their spectrum of activity
against the test microorganisms; the bioactive
secondary metabolites of these isolates were
extracted and their antimicrobial activities confirmed
through the secondary screening process as presented
in Table 4.
Based on the result of secondary screening, only
extracts from 2 out of 5 isolates gave significant
zones of inhibition against 5 fungal test organisms.
Antifungal activities of these 2 effective isolates
were then compared with standard antifungal drugs
and the results presented in Figure 1.
The two actinomycetes isolate whose crude extracts
produced significant zones of inhibition against
fungal test organisms were subjected physiological
and biochemical tests as shown in table 5.
Furthermore, the actinomycetes isolate with the best
antimicrobial activity was selected for molecular
identification by 16S ribosomal RNA gene
sequencing; rRNA banding profile is shown in plate
1
Table 4: Antimicrobial activities of selected actinomycetes isolate crude extracts
- Inactive against test organism; Values are means±SD
Figure 1: Antifungal activities of crude extracts compared to standard antifungals
0
5
10
15
20
25
30
CYP1 CYP2 Nystatin Fluconazole
Zonesofinibition(mm)
C. albicans
Mucor sp.
A. niger
A.fumigatus
Fusarium sp.
Test microorganisms Antimicrobial activity (Zones of inhibition in mm)
BYQ3 CYP1 CYP2 CYP4 CYQ2
Escherichia coli 3 ± 0.6 2 ± 0.0 4 ± 1.0 2 ± 0.0 3 ± 0.1
Pseudomonas aeruginosa - - 2 ± 0.6 - -
Staphylococus aureus 2 ± 0.6 2 ± 0.0 3 ± 1.8 3 ± 1.0 -
Salmonella typhi - 3 ± 1.0 - 4 ± 1.7 2 ± 0.0
Candida albicans - 26 ± 0.5 20 ± 0.6 - -
Klebsiella pneumoniae 3 ± 0.0 2 ± 0.6 - 3 ± 0.6 -
Mucor sp. 2 ± 0.0 23 ± 1.5 18 ± 2.0 - -
Aspergillus niger - 17 ± 1.0 12 ± 1.5 - 4 ± 1.0
Aspergillus fumigatus - 18 ± 1.5 14 ± 1.5 - 3 ± 1.8
Fusarium sp. - 9 ± 2.0 - - -
8. DISCUSSION
In this present study, out of 28 different actinomycete
isolates recovered from the soil samples, the greatest
percentage (39%) and also the highest average count
(3.6×104
± 1.9 CFU/g) came from sample site C
which is characterized by sandy soil with dense
grasses cover. This relatively high population can be
attributed to high plant roots density of the sample
site. Geetanjali and Jain (2016) and Muleta and
Assefa (2018) also inferred that rhizospheric soils
harbour greater percentages of actinomycetes.
Sample sites B (Loamy soil with forest canopy
cover) and D (Refuse dump site with sandy soil) had
similar percentages of the recovered isolates, 21%
and 25% and average counts 3.3×104
± 1.2 CFU/g
and 3.1×104
± 0.7 CFU/g respectively. These figures
are higher those obtained from sample site A
(Clayey, water lodged soil with sparse vegetation)
with 14% of the recovered isolates and an average
count of 3.0×104
± 2.4 CFU/g. Sparse vegetation,
lower organic matter content as well as higher
moisture content of the water lodged, clayey soil of
sample site A, might have contributed to the lower
figures obtained from the site (Hasani et al., 2014;
Nanjwade et al., 2010; Williams et al., 1972).
Literature accounts show that plating 1g of soil can
yield up to 109
microorganisms, and bacteria account
for about 4.2 × 106
CFU/g of the soil dry weight
(Torsvik, and Ovreas, 2002). However, the highest
average actinomycetes count (3.6×104
± 1.9 CFU/g)
recorded in this study was lower than the expected.
This may be somewhat due to the slightly acidic pH
of the soil samples.
Out of 28 actinomycetes isolates taken through
primary screening, 10 (36%) exhibited varying
degrees of antagonistic activities against the 10 test
organisms with 80% of the potent isolates recovered
from the rhizospheric soils. The present result is in
agreement with that of Dhawane and Zodpe (2017)
who concluded that actinomycetes from rhizospheric
soils are good sources of antimicrobial substances.
Abo-Shadi et al. (2010) also inferred that
rhizospheric soils could serve as viable sources of
bioactive metabolites. However, the percentage of
potent isolates (36%) obtained in this present study is
higher than the 12.82 % and 26.7% obtained by
Kumar et al. (2010) and Bizuye et al. (2013)
respectively, but lower than 60% reported by Muleta
and Assefa (2018). These differences could be due to
variances in antimicrobial susceptibility of the test
microorganisms or differences in genetic makeup of
the antimicrobial-producing actinomycetes (Muleta
and Assefa, 2018).
Out of the 10 distinct isolates that showed
antimicrobial capabilities, 5 (50%) i.e. BYQ3, CYP1,
CYP2, CYP4 and CYQ2, showed wide spectrum of
activity. Isolates AXP1, BYQ4, CYQ1 and CYQ7
(40%) were found to inhibit 3 of the test organisms
while isolate DYQ4 inhibited 2 test organisms.
Seven of the actinomycete isolates (70%) inhibited E.
coli, 6 isolates (60%) inhibited C. albicans and K.
pneumonia, 50% inhibited S. aureus while 40%
inhibited S. typhi, A. niger and A. fumigatus. The
least susceptible test organisms were Mucor sp.,
Fusarium sp. and P. Aeruginosa, inhibited by only
30% of the potent actinomycetes isolates.
All the 10 isolates selected for primary screening
grew on ISP-2 agar with typical actinomycetes
morphology; slow growing colonies, aerobic, tough,
leathery or rough/smooth, chalky and varying colours
of aerial mycelia. Diffusible pigment was observed in
4 of the isolates (CYP1, CYP2, CYP4 and CYQ2) on
ISP-2 agar. These features imply that the
actinomycete isolates belong to the Streptomyces
genus (Muleta and Assefa, 2018).
The five actinomycete isolates with wide spectrum
antimicrobial activity on primary screening were
further screened for bioactive compound production
through fermentation and agar well diffusion of
crude extracts. Production of zones of growth
inhibition of test organisms on agar plates indicated
the antimicrobial capacity of the bioactive extracts.
The range of growth inhibition zones recorded for
crude extracts against organisms in the present stud
was 0 mm his is higher than figures from
Chaudhary et al. (2013), Muleta and Assefa (2018)
and Priyadarshini et al. (2016), who reported highest
9. inhibition zones of 15mm, 17mm and 22mm
respectively. It is however lower than 40mm reported
by Bizuye et al. (2013) and 30mm reported by
Pandey et al. (2011). These differences may be due
to genetic variations in the antimicrobial producing
isolates and differences in fermentation conditions.
Some isolates that were active on primary screening
exhibited different activities on secondary screening.
A number of the very active isolates of primary
screening showed little activity on secondary
screening whereas some displayed improved activity.
Pandey et al. (2011) concluded that it is customary to
encounter actinomycete isolates that exhibit
antimicrobial activity on agar but not in broth media.
Out of the 5 selected isolates in this present study,
only extracts from 2 isolates (CYP1 and CYP2)
showed significant activities against 5 fungal test
organisms.
Crude extract from isolate CYP1 gave the highest
zones of inhibition; 26mm, 23mm, 18mm, 17mm and
9mm against Candida albicans, Mucor sp.,
Aspergillus fumigatus, Aspergillus niger and
Fusarium sp., respectively. These figures are greater
than 20mm, 16mm and 12mm recorded by Mohan et
al. (2014) against Candida albicans, Aspergillus
niger and Aspergillus fumigatus respectively, by
antifungal gents extracted from actinomycetes
isolated from marine sediments. Wadetwar and Patil
(2013) also reported narrower zones of 10mm against
Candida albicans and 8mm against Aspergillus
niger. Sharma and Parihar (2010) however recorded
wider zones of 23mm and 19mm against Candida
albicans and Fusarium sp respectively. Wider zones
of inhibition recorded by Sharma and Parihar (2010)
may largely be due to solvent extraction of the crude
fermentation broth before its antimicrobial assay.
Comparing the antifungal activities of extracts from
isolates CYP1 and CYP2 with those of standard
antifungals, nystatin and fluconazole, extract from
isolate CYP1 gave wider zones of inhibition than
nystatin (20µ/ml) and fluconazole (10µ/ml). Lower
susceptibility of the test fungi to standard antifungal
agents may be attributed to the increasing number of
antifungal resistant strains.
Physiological and biochemical characterization of
isolates CYP1 and CYP2 gave results similar to
those obtained from other previous research on the
genus Streptomyces (Chaudhary et al., 2013; Mohan
et al., 2014; Priyadarshini et al., 2016). Additional
molecular studies were done to further identify of
isolate CYP1. This isolate was selected for molecular
analysis because it had the best antimicrobial effects
on secondary screening. Molecular study was based
on 16S rRNA gene analysis because the gene has
some variable regions with sequence divergence
(Priyadarshini et al., 2016). The results obtained
from partial sequencing of the 16S rRNA gene (see
appendix) supported the fact that isolate CYP1 is
closely related (99% identical) to Streptomyces albus
(strain DSM 40313) of the family
Streptomycetaceae, order Actinomycetales and class
Actinobacteria.
CONCLUSION
The findings of this study revealed that the
antimicrobial metabolite extracted from (identified as
Streptomyces albus) has antifungal activities. The
results also demonstrated the broad-spectrum nature
of activity of the compound and its potency against
Candida albicans, Mucor sp., Aspergillus fumigatus,
Aspergillus niger and Fusarium sp.
The findings also showed that actinomycetes isolated
from rhizospheric soils have better antimicrobial-
producing potentials than others do. It is
recommended that isolate CYP1 and all other isolates
from this study be further processed to identify their
full antimicrobial potentials. There is also a need for
optimisation studies to know the best fermentation
parameters for bioactive metabolite production by the
actinomycete isolates.
ACKNOWLEDGEMENTS
The author is grateful to Professor S.E. Omonigho,
for supervising this research work; and also to
Professor (Mrs) F.E. Oviasogie, and the entire staff
of Microbiology Department, University of Benin,
Benin City.
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