This study evaluated the antimicrobial activity of bacteriocin produced by Lactobacillus isolated from curd samples against common pathogens. Lactobacillus strains were isolated from curd using MRS media and identified through morphological and biochemical tests. The isolates were screened for bacteriocin production using agar well diffusion assay against E. coli and Staphylococcus aureus. Clear inhibition zones were observed around the wells containing supernatant from Lactobacillus cultures, indicating they produced bacteriocin with antimicrobial activity against the test pathogens. This demonstrates the potential of using bacteriocin from Lactobacillus as natural preservatives.
Isolation, Identification of Probiotic Bacteria Present in Milkijtsrd
The aim ofThe aim of this study was to present some data on isolation, growth, and antimicrobial activity, effect of pH, heat, and sensitivity to proteolytic enzymes of lactobacillus as probiotic bacteria. A large amount of probiotic bacteria is present in milk or milk products which are mainly lactic acid bacteria (LAB). Lactic acid bacteria (LAB) including Lactobacillus spp. Isolation, identification of lactic acid bacterial (LAB) was done by Gram' staining and catalase test and further confirmation was based on morphological, cultural, physiological and different biochemical tests. A total four isolates viz. Lactobacillus fermentum, L. casei, L. acidophilus and bifid bacterium longum was identified after different biochemical analysist which were also showed reliable probiotic properties. The antibacterial activity of lactic acid bacteria (LAB) isolated from raw milk against common enteric pathogens. The antagonistic properties of these isolates against Escherichia coli, Staphylococcus aureus, were examined using agar well diffusion method. this study was to present some data on isolation, growth, and antimicrobial activity, effect of pH, heat, and sensitivity to proteolytic enzymes of lactobacillus as probiotic bacteria. A large amount of probiotic bacteria is present in milk or milk products which are mainly lactic acid bacteria (LAB). Lactic acid bacteria (LAB) including Lactobacillus spp. Isolation, identification of lactic acid bacterial (LAB) was done by Gram' staining and catalase test and further confirmation was based on morphological, cultural, physiological and different biochemical tests. A total four isolates viz. Lactobacillus fermentum, L. casei, L. acidophilus and Bifidobacterium longum was identified after different biochemical analysist which were also showed reliable probiotic properties. The antibacterial activity of lactic acid bacteria (LAB) isolated from raw milk against common enteric pathogens. The antagonistic properties of these isolates against Escherichia coli, Staphylococcus aureus, were examined using agar well diffusion method. Shobha Mehra | Vimla Mehra | Dinesh Bhauryal"Isolation, Identification of Probiotic Bacteria Present in Milk" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-5 , August 2018, URL: http://www.ijtsrd.com/papers/ijtsrd16979.pdf http://www.ijtsrd.com/biological-science/biotechnology/16979/isolation-identification-of-probiotic-bacteria-present-in-milk/shobha-mehra
Bacteriocin are produced from lactic acid bacteria .
various lactic acid bacteria produces different kinds of bacteriocin .
Bacteriocin can be used as food preservative
Isolation, Identification of Probiotic Bacteria Present in Milkijtsrd
The aim ofThe aim of this study was to present some data on isolation, growth, and antimicrobial activity, effect of pH, heat, and sensitivity to proteolytic enzymes of lactobacillus as probiotic bacteria. A large amount of probiotic bacteria is present in milk or milk products which are mainly lactic acid bacteria (LAB). Lactic acid bacteria (LAB) including Lactobacillus spp. Isolation, identification of lactic acid bacterial (LAB) was done by Gram' staining and catalase test and further confirmation was based on morphological, cultural, physiological and different biochemical tests. A total four isolates viz. Lactobacillus fermentum, L. casei, L. acidophilus and bifid bacterium longum was identified after different biochemical analysist which were also showed reliable probiotic properties. The antibacterial activity of lactic acid bacteria (LAB) isolated from raw milk against common enteric pathogens. The antagonistic properties of these isolates against Escherichia coli, Staphylococcus aureus, were examined using agar well diffusion method. this study was to present some data on isolation, growth, and antimicrobial activity, effect of pH, heat, and sensitivity to proteolytic enzymes of lactobacillus as probiotic bacteria. A large amount of probiotic bacteria is present in milk or milk products which are mainly lactic acid bacteria (LAB). Lactic acid bacteria (LAB) including Lactobacillus spp. Isolation, identification of lactic acid bacterial (LAB) was done by Gram' staining and catalase test and further confirmation was based on morphological, cultural, physiological and different biochemical tests. A total four isolates viz. Lactobacillus fermentum, L. casei, L. acidophilus and Bifidobacterium longum was identified after different biochemical analysist which were also showed reliable probiotic properties. The antibacterial activity of lactic acid bacteria (LAB) isolated from raw milk against common enteric pathogens. The antagonistic properties of these isolates against Escherichia coli, Staphylococcus aureus, were examined using agar well diffusion method. Shobha Mehra | Vimla Mehra | Dinesh Bhauryal"Isolation, Identification of Probiotic Bacteria Present in Milk" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-5 , August 2018, URL: http://www.ijtsrd.com/papers/ijtsrd16979.pdf http://www.ijtsrd.com/biological-science/biotechnology/16979/isolation-identification-of-probiotic-bacteria-present-in-milk/shobha-mehra
Bacteriocin are produced from lactic acid bacteria .
various lactic acid bacteria produces different kinds of bacteriocin .
Bacteriocin can be used as food preservative
An overview of lactic acid bacteria - IJBInnspub Net
Lactic acid bacteria (LAB) are renowned for the potential of producing antimicrobial compound and other value added products. Undeniable to concern these probiotic has contributed to the importance of human life. Deserving an attention for its capabilities, this paper will discuss on the general description of lactic acid bacteria, genetics, metabolism and its application to the industries. Get the full articles at: http://www.innspub.net/volume-1-number-3-june-2011/
Secondary screening of industrial important microbes DhruviSuvagiya
Detection and isolation of a microorganism from a natural environment like soil containing large number of microbial population is called as screening. It is very time consuming and expensive process.
An overview of lactic acid bacteria - IJBInnspub Net
Lactic acid bacteria (LAB) are renowned for the potential of producing antimicrobial compound and other value added products. Undeniable to concern these probiotic has contributed to the importance of human life. Deserving an attention for its capabilities, this paper will discuss on the general description of lactic acid bacteria, genetics, metabolism and its application to the industries. Get the full articles at: http://www.innspub.net/volume-1-number-3-june-2011/
Secondary screening of industrial important microbes DhruviSuvagiya
Detection and isolation of a microorganism from a natural environment like soil containing large number of microbial population is called as screening. It is very time consuming and expensive process.
Dr. Tom Rehberger - Early Colonizing Bacteria in the GI Tract - Lessons from ...John Blue
Early Colonizing Bacteria in the GI Tract - Lessons from Poultry and Strategies for Swine - Dr. Tom Rehberger, President, Agro BioSciences, from the 2016 Allen D. Leman Swine Conference, September 17-20, 2016, St. Paul, Minnesota, USA.
More presentations at http://www.swinecast.com/2016-leman-swine-conference-material
ISOLATION AND IDENTIFICATION OF LACTIC ACID BACTERIA FROM PLANTS AND OTHER ...American Research Thoughts
Twenty-two lactic acid bacteria (LAB) belonging to Lactobacillus, Lactococcus and
Enterococcus genera were isolated from plants, flowers and other vegetable matrices. The predominant
LAB species were Lactobacillus brevis (57%) followed to Lactobacillus delbrueckii subsp. bulgaricus
(14%) and Lactococcus lactis (14%). Among enterococci E. faecalis (4 /50%), E. faecium (2 /25%), E.
hirae (2 /12,5%) were isolated. The strains were identified previously with biochemical kits and then
confirmed by PCR. Bacteria isolated were tested against nine strains selected among pathogenic and
opportunistic strains to evaluate their capacity to produce BLS (bacteriocin like substance).
Subsequently to demonstrate the horizontal transfer of genes coding for the production of bacteriocin
substances, a conjugation experiment was positively carried out between an Enterococcus faecium
used as donor and a Lactobacillus acidophilus used as recipient.
A short presentation on how to create a Lactobacillus culture (LAB) for use in horticulture. This can be a basis for many things from fermentation to odour control - But by far the best is for making your own free organic liquid plant food!!
Isolation and Identification High-Biological Activity Bacteria in Yogurt Qua...IJMER
Six strains of lactic bacteria and seven strains of acetic bacteria which were isolated from
fermented food. The screening secured one strain of lactic acid bacterium LB4 which carried strong
probiotic activity and one strain of acetic acid bacterium AB7 which was capable to generate high
glucuronic acid. Activities of probiotic and glucuronic acid were useful biological activities for health
protection and enhancing. The results of DNA sequencing showed LB4 was similar to Lactobacillus
acidophilus and AB7 was similar to Gluconacetobacter nataicola with 100% of similar proportion. Both
of these bacteria were safe that could be used in food fermentation.Six strains of lactic bacteria and seven strains of acetic bacteria which were isolated from
fermented food. The screening secured one strain of lactic acid bacterium LB4 which carried strong
probiotic activity and one strain of acetic acid bacterium AB7 which was capable to generate high
glucuronic acid. Activities of probiotic and glucuronic acid were useful biological activities for health
protection and enhancing. The results of DNA sequencing showed LB4 was similar to Lactobacillus
acidophilus and AB7 was similar to Gluconacetobacter nataicola with 100% of similar proportion. Both
of these bacteria were safe that could be used in food fermentation.
Preservative potentials of crude bacteriocins produced by Lactobacillus tucce...iosrjce
IOSR Journal of Biotechnology and Biochemistry (IOSR-JBB) covers studies of the chemical processes in living organisms, structure and function of cellular components such as proteins, carbohydrates, lipids, nucleic acids and other biomolecules, chemical properties of important biological molecules, like proteins, in particular the chemistry of enzyme-catalyzed reactions, genetic code (DNA, RNA), protein synthesis, cell membrane transport, and signal transduction. IOSR-JBB is privileged to focus on a wide range of biotechnology as well as high quality articles on genetic engineering, cell and tissue culture technologies, genetics, microbiology, molecular biology, biochemistry, embryology, cell biology, chemical engineering, bioprocess engineering, information technology, biorobotics.
Isolation and Characterization of Bacteriocin Producing Lactic Acid Bacteria ...inventionjournals
Bacteriocins are the extracellular proteins produced by the bacteria which inhibit the growth of similar or closely related bacterial strains. Lactic Acid Bacteria (LAB) are predominantly present in the fermented foods produce bacteriocins. In the present study, six strains (three strains each) were isolated from the fermented Bengal gram samples containing with husk and without husk.The organisms isolated were identified as Pediococcussp and Yeast sp.by the biochemical characterization. The bacteriocins produced by these organisms effectively inhibited the growth of E.coli, Klebsiellasp, Staphylococcus aureus, and Pseudomonas aerugenosabut couldn’t inhibit the growth of Proteus vulgaris and Bacillus sp. Strains c2 and c3 showed greater activity at low pH. All the strains showed antibacterial activity against Bacillus sp,E.coli, Klebsiellasp, Staphylococcus aureusand Pseudomonas aerugenosabut Proteus vulgaris showed high resistance when bacteriocin was exposed to temperatures 37°C and 80°C.
Isolation and Characterization of Bacteriocin Producing Lactic Acid Bacteria ...inventionjournals
Bacteriocins are the extracellular proteins produced by the bacteria which inhibit the growth of similar or closely related bacterial strains. Lactic Acid Bacteria (LAB) are predominantly present in the fermented foods produce bacteriocins. In the present study, six strains (three strains each) were isolated from the fermented Bengal gram samples containing with husk and without husk.The organisms isolated were identified as Pediococcussp and Yeast sp.by the biochemical characterization. The bacteriocins produced by these organisms effectively inhibited the growth of E.coli, Klebsiellasp, Staphylococcus aureus, and Pseudomonas aerugenosabut couldn’t inhibit the growth of Proteus vulgaris and Bacillus sp. Strains c2 and c3 showed greater activity at low pH. All the strains showed antibacterial activity against Bacillus sp,E.coli, Klebsiellasp, Staphylococcus aureusand Pseudomonas aerugenosabut Proteus vulgaris showed high resistance when bacteriocin was exposed to temperatures 37°C and 80°C.
Isolation and Characterization of Bacteriocin Producing Lactic Acid Bacteria ...inventionjournals
Bacteriocins are the extracellular proteins produced by the bacteria which inhibit the growth of similar or closely related bacterial strains. Lactic Acid Bacteria (LAB) are predominantly present in the fermented foods produce bacteriocins. In the present study, six strains (three strains each) were isolated from the fermented Bengal gram samples containing with husk and without husk.The organisms isolated were identified as Pediococcussp and Yeast sp.by the biochemical characterization. The bacteriocins produced by these organisms effectively inhibited the growth of E.coli, Klebsiellasp, Staphylococcus aureus, and Pseudomonas aerugenosabut couldn’t inhibit the growth of Proteus vulgaris and Bacillus sp. Strains c2 and c3 showed greater activity at low pH. All the strains showed antibacterial activity against Bacillus sp,E.coli, Klebsiellasp, Staphylococcus aureusand Pseudomonas aerugenosabut Proteus vulgaris showed high resistance when bacteriocin was exposed to temperatures 37°C and 80°C
Anti-Microbial Activity of probiotic Lactobacilli and Optimization of Bacteri...ijsrd.com
The present study is about the anti-microbial activity of the bacteriocin producing lactobacilli and optimization of bacteriocin production. Bacteriocin was extracted by solvent extraction with chloroform and the antimicrobial activity was tested against 5 different pathogens by agar spotting method. Optimization of bacteriocin production was done for 4 different parameters such as pH, Temperature, Carbon source and Nitrogen source and the anti-microbial activity was tested against the following 5 different pathogens and the results were observed and diameter of the zone of inhibition was measured and tabulated. From the results of the study it was found that bacteriocin produced from lactobacilli has good antimicrobial activity.The present study is about the anti-microbial activity of the bacteriocin producing lactobacilli and optimization of bacteriocin production. Bacteriocin was extracted by solvent extraction with chloroform and the antimicrobial activity was tested against 5 different pathogens by agar spotting method. Optimization of bacteriocin production was done for 4 different parameters such as pH, Temperature, Carbon source and Nitrogen source and the anti-microbial activity was tested against the following 5 different pathogens and the results were observed and diameter of the zone of inhibition was measured and tabulated. From the results of the study it was found that bacteriocin produced from lactobacilli has good antimicrobial activity.
Role of Bacteriocins in food preservation. Food safety is a growing public he...nehamicro999
Role of Bacteriocins in Food preservation. Food safety is a growing public health concern of both in the developing countries. Bacteriocins are antibacterial proteins produced by many lactic acid bacteria in fermented, and non- fermented foods. Presently, nisin is the only bacteriocin which is used as a food preservative in many countries of the world. Bacteriocins are inhibitory against food borne pathogens, and bacteriocins resistance is not usually genetically determined.
Optimizing The Bacteriocin Production In Strain Of Lactobacillus pentosus Iso...Innspub Net
MRS agar was used for the isolation of Lactobacillus strain. This strain was recognized through biochemical tests and 16S rRNA ribotyping, as Lactobacillus pentosus. Its antibacterial effects were detected by utilizing cell free supernatant (CFS). Escherichia coli, Bacillus subtilis and Staphylococcus aureus were used as test strains. CFS showed antimicrobial activity against the test strains. CFS was treated with proteinases for the confirmation of loss of antimicrobial activity. Loss of antimicrobial activity on exposure to proteinases indicated the presence of bacteriocin in CFS. CFS was also studied for its antimicrobial effect at different temperatures and pH. Optimum antimicrobial effect was recorded at pH 7 and at temperature 45°C. The current study indicates the antimicrobial activity of strain of L. pentosus against E. coli, B. subtilis and S. aureus.
Isolation studies of Bacteriocin producing Lactic Acid Bacteria from raw goat...Premier Publishers
Probiotics are live microorganisms which when administered in appropriate amount gives health benefit on the host. In the current study raw goat milk obtained from Belapur village (Belapur, Navi Mumbai, Pin-400614, Maharashtra, India) was the source of isolated lactic acid bacteria. Out of 118 screened isolates, only one isolate i.e. RL 76 showed antimicrobial activity upon primary screening. Optimization of the isolate was carried out to check its bacteriocin producing potential. Isolate grew well at 370C and pH 7. Isolate RL 76 tolerated 2% of bile salt and showed no haemolytic activity. Upon morphological and biochemical tests, the isolate RL76 was identified as Lactobacillus casei. The extracted cell free supernatant was partially purified by ammonium sulphate precipitation. Partially purified cell free supernatant showed antibacterial activity against Staphylococcus aureus, Streptococcus fecalis, Klebsiella pneumonia, Pseudomonas aeruginosa, Salmonella typhi and Escherichia coli. The study indicates potential of the isolate as a good probiotic species.
“Microbiological Analysis Of Soy Milk Produced From Soybean”iosrjce
The soy milk was prepared using the soaked soybean seeds then soy milk was treated with Na2CO3
and NaHCO3 for the preservation. By spread plate method and streak plate method two bacteria Escherichia
spp and Streptococcus spp were isolated respectively .These bacteria were subjected to biochemical and
microbiological analysis. In Biochemical analysis IMVIC test was performed. Both the bacteria Escherichia spp
and Streptococcus spp are positive for Methyl red test and citrate utilization whereas both the bacteria are
negative for Voges-Proskauer test and for Indole production test Escherichia spp is positive and Streptococcus
spp is negative. In case of microbiological test Escherichia spp is gram negative and Streptococcus spp is gram
positive. Both these bacteria have catalase production ability
1. AN EVALUATION OF ANTIMICROBIAL ACTIVITY
OF BACTERIOCIN PRODUCING LACTOBACILLUS
AGAINST HUMAN PATHOGENS
Presented by the fulfillment of
Bsc. Biotechnology degree under
M.G.University
Conducted at UniBiosys
research lab.
Submitted by,
Mubeena.K.S
Roll no: 12155184
M.E.S.College
2. INTRODUCTION
• Bacteriocin producing strains of lactic acid bacteria showing
antimicrobial properties have been utilised for controlling food
spoilage, food-borne pathogens, improve food fermentation
processes etc.
• Lactic acid bacteria (LAB) is a group of industrial microorganism
involved in the processing of various fermented food which include
vegetables and sausages, dietary adjuncts, probiotics and even
cosmetic ingredients.
• This study was focused on isolation and characterization of
bacteriocin-producing Lactobacillus from curd samples and its
inhibitory nature against common human pathogens.
3. •Bacteriocins are proteinaceous antibacterial compounds and exhibit
bactericidal activity against species closely related to the producer
strain and many bacteriocins are active against food-borne
pathogens.
• The bacterial strains includes are E coli, Bacillus cereus, Clostridium
botulinum, Staphylococcus aureus and Listeria monocytogenes.
•Lactic acid bacteria (LAB) which are predominantly present in
the fermented foods are well known for producing bacteriocins.
•The inhibitory activity towards spoilage microorganisms is the result
of the metabolic product secreted by these LAB which acts as
antimicrobial compounds.
4. •Bacteriocins are extracellularly produced primary compounds of
bacterial ribosomal synthesis which have a relatively narrow
spectrum of bactericidal activity .
•Nisin, is the bacteriocin produced by Lactococcus lactis, is
most widely used as food preservative.
•Isolated Bacteriocin producing species of lactobacilli may be
used as protective cultures to improve the microbial safety of
food.
5. Aim and objectives
•This work aims to evaluate the bacteriocin activity of Lactobacilli
strains isolated from domestically prepared curd.
• The lactic acid bacteria is screen for their ability to produce
bacteriocin which exhibit antagonistic activity against indicator
strains.
• Lactobacillus were isolated using MRS media from different curd
samples ,were screened for bacteriocin production.
•The Lactobacillus strains were able to produce bacteriocin whose
antibacterial activity was analyzed by agar well diffusion assay test
against pathogenic organisms like e.coli and Staphylococcus aureus.
6. MATERIALS AND METHODS
Isolation of lactic acid bacteria
• Biochemical tests
• Microscopical observation
Effect of antimicrobial activity
Identification of LAB
7. Isolation of lactic acid bacteria
• Lactobacillus strains were isolated from domestically prepared
curd samples.
• sample was serial diluted and Diluted samples were plated
onto De Man Rogosa Sharpe (MRS) medium for Lactobacillus
isolation and incubated at 37°C for 48 hours under anaerobic
condition.
• Isolated colonies with typical characteristics of LAB were
picked from each plate and sub cultured into MRS broth and
nutrient agar slant.
8. Identification of Lactic acid bacteria (LAB)-Lactobacillus
•Further identification of the Lactobacilli was performed according to
their morphological, cultural, physiological and biochemical
characteristics as described by Bergey’s Manual of Systematic
Bacteriology
•The morphology of cultures were identified using Gram’s staining and
spore forming test.
.
Biochemical tests
•Cultures of Lactobacillus sp. were further characterised for Spore
forming test, Catalase test,Methyl Red test, Voges Prauskeur
test,Citrate test, Starch hydrolysis and Glucose fermentation test.
•The results of the biochemical tests were used to confirm
Lactobacillus sp. and differentiate the biovariants based on their
response to glucose fermentation analyses.
9. Screening for bacteriocin production
•The cultures of the indicator strains (Staphylococcus aureus and E.
coli) were prepared by spreading 0.1ml of the inoculum onto MHA
plates.
•4 wells of diameter 8 mm were made in each of the plates using
sterilized well cutter.
•The sample was subjected to 100% ammonium sulphate precipitation.
Agar well diffusion assay
•The two wells were filled with different concentrations of sample, one
well with 30µl antibiotic (chloramphenicol) and other kept as control.
•Inhibition zones around the wells were measured and recorded in
millimeter.
10. RESULTS
Isolation of lactic acid bacteria
• The colonies were isolated from curd sample using MRS agar
medium.
• The colonies were identified as creamy white, transparent, mucoid
and smooth round in shape.
12. Identification of morphology
Gram’s staining
Violet coloured Gram positive rod bacteria was observed
under microscope.
Fig:2 Microscopical observation of
Lactobacillus
13. Biochemical reactions
Table:1 Biochemical properties of Lactobacillus
TEST RESULT
Spore forming test Negative
Catalase test Negative
Methyl Red Positive
Voges Prauskeur test Negative
Citrate Negative
Starch hydrolysis Positive
Glucose fermentation test Positive (acid and gas)
Tentative identification Lactobacillus sp
15. Screening for bacteriocin production
Agar well diffusion assay
• The Lactobacillus strains was found to show an antibacterial
activity in the well diffusion assay.
• The antibacterial substance produced by Lactobacillus
inhibited pathogen such as Staphylococcus aureus and E. coli.
• Clear zone was observed around the wells.
• The inhibition zone obtained in E.coli plate is between 5-8mm
and inhibition zone obtained in Staphylococcus plate is
between 4-9mm.
16. Fig:3 Plate showing inhibition towards
E.coli
Fig:4 Plate showing inhibition towards
Staphylococcus aereus
C1-antibiotic(chloramphenicol) , C2-control , 1-100 µl and 2-150 µl