This document summarizes a study that investigated the effects of environmental conditions on the growth and lipid accumulation of the diatom Nitzschia communis. The study tested two different media types designed to mimic natural saline groundwater, across a range of temperatures and salt concentrations. It found that growth rate was slightly higher in one medium, while lipid yield was higher in the other. Lipid yields were highest at elevated salt concentrations and across a broad range of temperatures. Substituting individual salt components between the two media indicated higher lipid yield in one was associated with lower magnesium chloride concentration. The aim was to identify microalgae suitable for renewable liquid fuel production in arid southwest US environments.
2017 - Comparison of nitrifying microbial communities of two full-scale membr...WALEBUBLÉ
Barbarroja, P., Moreno-Mesonero, L., Zornoza, A., Fernández-Navarro, J., Alonso, J.L., Muñagorri, F., García, C., Álvarez, C. (2017) Comparison of nitrifying microbial communities of two full-scale membrane bioreactors treating wastewaters from municipal solid wastes using 16S rDNA gene amplicon sequencing. 7th congress of European microbiologists FEMS 2017, Valencia, Spain, 9-13 July 2017.
Research Inventy : International Journal of Engineering and Scienceinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Biochemical Alternation In Fresh Water Fishe Labeo Rohita Exposed To The Sodi...iosrjce
Fishes are regarded as an important high grade protein containing food staple of Indian people.
Ever increasing water pollution level, especially sodium fluoride (NaF), in inland freshwater reservoir has
made significant biochemical changes in the life cycle of fishes. In view of this, the investigations on effects of
acute and chronic sodium fluoride toxicity to fish Labeo rohita have been carried out. The changes in glycogen,
protein and lipid content of selected tissues like muscle, liver, gill and kidney were examined. The study
revealed a highest loss of glycogen, protein and lipid percentage in all tissues as compared to control.
Phosphorus mineralization of bioslurry and other manures in soil Premier Publishers
The experiment was conducted to see the phosphorus (P) mineralization pattern of bioslurry under aerobic and anaerobic soil conditions. Two bioslurry (cowdung bioslurry and poultry manure bioslurry) and their original manure (cowdung and poultry manure) at 3, 5, 10 and 20 t ha-1, respectively were thoroughly mixed with soil and incubated in aerobic and anaerobic moisture condition for 12 weeks. Among the four different types of manure, P release from poultry manure slurry was the highest. Poultry manure and cowdung slurry recorded very closer amount of available P. Both cowdung slurry and poultry manure slurry released higher amount of P compared to their original state (cowdung and poultry manure). P mineralization reaches in peak within 4-6 weeks of incubation. Under anaerobic condition the P mineralization was found higher compared to aerobic condition. The P mineralization data fitted strongly to the first order kinetic model. The bioslurries had lower rate of mineralization but had higher potentiality to release P in the soil compared to their original state.
Optimal Salinity, Nitrate and Phosphate Concentrations on Germination and Gro...iosrjce
The effects of salinity, nitrate (N) and phosphate (P) concentrations on the germination of Enhalus
acoroides seeds and growth were studied under laboratory condition. The highest percentage of seed
germination was at 20 ppt salinity for all concentrations of Nand P. However, there was not different (P >0.05) in
the percentage of germinated seed compared with other salinity levels of 25 and 30 ppt at all N and P concentrations. In
regard to the growth rate of seedling was found to be effective to the extension of root and lengths. In present
study, root and leaf lengths of E. acoroides seedling were observed to be significantly declined when the level of
salinity and N and P concentrations increased. Hence, alteration in the major nutrient concentration indicates
the vulnerability of E. acoroides seagrass under culturing laboratory condition, which must be avoidably
approached prior to transplantation into the meadow area for conservative management of seagrass resource.
The Influence of Vermiculite on the Uptake of Silver Nanoparticles in a Terre...Agriculture Journal IJOEAR
— The uptake of silver from silver nanoparticles in soil was investigated in the presence of increasing concentrations of Vermiculite, typical 2:1 clay. Two insect species, Acheta domesticus and Tenebrio molitor, and two plant species, Helianthus annuus and Sorghum vulgare, were exposed to silver nanoparticles in the presence of increasing concentrations of Vermiculite in soil. Silver nanoparticles were characterized using techniques including transmission electron microscopy, dynamic light scattering, and powder X-ray diffraction. The levels of silver in test species exposed to silver nanoparticles were measured using an inductively coupled plasma-optical emission spectrometer. An increase in the cation exchange capacity of soil was observed with the increase in the concentration of vermiculite in soil. The results suggested a decrease in the uptake of silver from silver nanoparticles in soil by Acheta domesticus as a function of increasing concentrations of Vermiculite in soil. No apparent trend was observed in the remaining species. Both plant species were found to accumulate silver in their roots. The translocation of silver to stems and leaves was observed in the case of Helianthus annuus. Results from this study suggest that the presence of Vermiculite in soil could possibly decrease the uptake of silver from silver nanoparticles.
Aspects of the Geomorphology and Limnology of some molluscinhabited freshwate...iosrjce
IOSR Journal of Environmental Science, Toxicology and Food Technology (IOSR-JESTFT) multidisciplinary peer-reviewed Journal with reputable academics and experts as board member. IOSR-JESTFT is designed for the prompt publication of peer-reviewed articles in all areas of subject. The journal articles will be accessed freely online
DOI: 10.21276/ijlssr.2016.2.4.10
bio-indicators. The present study is focused on the effective use of L. rohita, an economically significant carp as a
bio-indicator of zinc pollution through its several physiological, histopathological biomarkers. Primarily, acute toxicity
test is performed in which the carp fingerlings are exposed to different concentrations (10, 20, 40, 80, 160, 320 ppm) of
zinc sulphate. 96 hour LC50 value is determined to be 100 ppm. It is taken as lethal concentration and the fishes are
exposed to it for a period of 96 hours during which wide range of behavioural abnormalities are evidenced like general
hyperactivity, surfacing activity, hyper-opercular activity, and erratic swimming pattern. It is followed by loss of balance
and convolutions. One fifth of the lethal concentration is taken (i.e., 10 ppm) as sub-lethal concentration and fishes are
exposed to it for a period of 15 days during which growth, behaviour, oxygen consumption, histopathology, hematology
and genotoxicity are studied. Negative growth performance is observed with insignificant length increment up to 0.24 %
and significant weight reduction up to -2.38 %. Wide range of behavioural abnormalities are evidenced which includes,
erratic swimming, hyperactivity, surfacing activity and depression in appetite. Besides, general body discolouration and
haemorrhage are observed as well. Rate of oxygen consumption showed a time dependant decrease which ranged up to
-49.10%. Gills of the fishes are shown to have conspicuous histopathological alterations like lamellar necrosis, lamellar
fusion, lamellar erosion, epithelial lifting and epithelial swelling. Key-words- Bioindicator, L. rohita, Zinc sulphate, Growth, Behaviour, Oxygen Consumption, Histopathology
Effects of Fungicides for Non Target Fungi Alternaria cassiaeIJEAB
The fungicides are used to control of pathogenic fungi in several tilth but they can affect negatively the microorganisms diversity of soil. The aim of this research was to evaluate the toxicity and environmental risk of tebuconazoles: captan, tebuconazole and the mixture chlorothalonil + propamocarb hidrochloride for fungi Alternaria cassiae. Each fungicide were performed three experiments in completely randomized design with three repetitions and the growth was evaluated daily. Inhibition concentration (IC50;7d) of tebuconazole was 3.49 mg L-1, the captan was 47.36 mg L-1 and of mixture chlorothalonil + propamocarb hidrochloride, 64.04 mg L-1. Tebuconazole is classified as moderately toxic and sensitivity, captan, low toxicity and sensitivity and the mixture, non toxic and insensitive but only captan showed possibility of adverse effect for A. cassiae.`
Removal of Cr (VI) Through the Use of the Agroindustrial Residue of the Perse...CrimsonpublishersMCDA
We analyzed the Chromium (VI) removal capacity in aqueous solution by the Persea americana biomass, using the diphenyl carbazide method to evaluate the metal concentration. Biosorption at different pH (1, 2, 3, and 4) was evaluate for different times. We too studied the effect of temperature in the range of 28 to 60 °C and the removal at different initial concentrations of Cr (VI) of 200 to 1000mg/L. Therefore, the highest biosorption of the metal (50mg/L) occurs within 270 minutes, at pH of 1.0 and 28 °C. According to temperature, the highest removal was observing at 60 °C, in 45 minutes, when the metal is completely adsorbed. At the analyzed concentrations of Cr (VI), fungal biomass, showed excellent removal capacity, besides it removes efficiently the metal in situ (100% removal in earth and water contaminated, after 5 and 6 days of incubation, 5 and 10g of biomass, 10g of earth and 100mL of water; so, it can be used to eliminate it from industrial wastewater.
https://crimsonpublishers.com/mcda/fulltext/MCDA.000570.php
For more open access journals in Crimson Publishers please click on link: https://crimsonpublishers.com
For more articles on journal of agronomy and crop science please click on below link: https://crimsonpublishers.com/mcda/
2017 - Comparison of nitrifying microbial communities of two full-scale membr...WALEBUBLÉ
Barbarroja, P., Moreno-Mesonero, L., Zornoza, A., Fernández-Navarro, J., Alonso, J.L., Muñagorri, F., García, C., Álvarez, C. (2017) Comparison of nitrifying microbial communities of two full-scale membrane bioreactors treating wastewaters from municipal solid wastes using 16S rDNA gene amplicon sequencing. 7th congress of European microbiologists FEMS 2017, Valencia, Spain, 9-13 July 2017.
Research Inventy : International Journal of Engineering and Scienceinventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Biochemical Alternation In Fresh Water Fishe Labeo Rohita Exposed To The Sodi...iosrjce
Fishes are regarded as an important high grade protein containing food staple of Indian people.
Ever increasing water pollution level, especially sodium fluoride (NaF), in inland freshwater reservoir has
made significant biochemical changes in the life cycle of fishes. In view of this, the investigations on effects of
acute and chronic sodium fluoride toxicity to fish Labeo rohita have been carried out. The changes in glycogen,
protein and lipid content of selected tissues like muscle, liver, gill and kidney were examined. The study
revealed a highest loss of glycogen, protein and lipid percentage in all tissues as compared to control.
Phosphorus mineralization of bioslurry and other manures in soil Premier Publishers
The experiment was conducted to see the phosphorus (P) mineralization pattern of bioslurry under aerobic and anaerobic soil conditions. Two bioslurry (cowdung bioslurry and poultry manure bioslurry) and their original manure (cowdung and poultry manure) at 3, 5, 10 and 20 t ha-1, respectively were thoroughly mixed with soil and incubated in aerobic and anaerobic moisture condition for 12 weeks. Among the four different types of manure, P release from poultry manure slurry was the highest. Poultry manure and cowdung slurry recorded very closer amount of available P. Both cowdung slurry and poultry manure slurry released higher amount of P compared to their original state (cowdung and poultry manure). P mineralization reaches in peak within 4-6 weeks of incubation. Under anaerobic condition the P mineralization was found higher compared to aerobic condition. The P mineralization data fitted strongly to the first order kinetic model. The bioslurries had lower rate of mineralization but had higher potentiality to release P in the soil compared to their original state.
Optimal Salinity, Nitrate and Phosphate Concentrations on Germination and Gro...iosrjce
The effects of salinity, nitrate (N) and phosphate (P) concentrations on the germination of Enhalus
acoroides seeds and growth were studied under laboratory condition. The highest percentage of seed
germination was at 20 ppt salinity for all concentrations of Nand P. However, there was not different (P >0.05) in
the percentage of germinated seed compared with other salinity levels of 25 and 30 ppt at all N and P concentrations. In
regard to the growth rate of seedling was found to be effective to the extension of root and lengths. In present
study, root and leaf lengths of E. acoroides seedling were observed to be significantly declined when the level of
salinity and N and P concentrations increased. Hence, alteration in the major nutrient concentration indicates
the vulnerability of E. acoroides seagrass under culturing laboratory condition, which must be avoidably
approached prior to transplantation into the meadow area for conservative management of seagrass resource.
The Influence of Vermiculite on the Uptake of Silver Nanoparticles in a Terre...Agriculture Journal IJOEAR
— The uptake of silver from silver nanoparticles in soil was investigated in the presence of increasing concentrations of Vermiculite, typical 2:1 clay. Two insect species, Acheta domesticus and Tenebrio molitor, and two plant species, Helianthus annuus and Sorghum vulgare, were exposed to silver nanoparticles in the presence of increasing concentrations of Vermiculite in soil. Silver nanoparticles were characterized using techniques including transmission electron microscopy, dynamic light scattering, and powder X-ray diffraction. The levels of silver in test species exposed to silver nanoparticles were measured using an inductively coupled plasma-optical emission spectrometer. An increase in the cation exchange capacity of soil was observed with the increase in the concentration of vermiculite in soil. The results suggested a decrease in the uptake of silver from silver nanoparticles in soil by Acheta domesticus as a function of increasing concentrations of Vermiculite in soil. No apparent trend was observed in the remaining species. Both plant species were found to accumulate silver in their roots. The translocation of silver to stems and leaves was observed in the case of Helianthus annuus. Results from this study suggest that the presence of Vermiculite in soil could possibly decrease the uptake of silver from silver nanoparticles.
Aspects of the Geomorphology and Limnology of some molluscinhabited freshwate...iosrjce
IOSR Journal of Environmental Science, Toxicology and Food Technology (IOSR-JESTFT) multidisciplinary peer-reviewed Journal with reputable academics and experts as board member. IOSR-JESTFT is designed for the prompt publication of peer-reviewed articles in all areas of subject. The journal articles will be accessed freely online
DOI: 10.21276/ijlssr.2016.2.4.10
bio-indicators. The present study is focused on the effective use of L. rohita, an economically significant carp as a
bio-indicator of zinc pollution through its several physiological, histopathological biomarkers. Primarily, acute toxicity
test is performed in which the carp fingerlings are exposed to different concentrations (10, 20, 40, 80, 160, 320 ppm) of
zinc sulphate. 96 hour LC50 value is determined to be 100 ppm. It is taken as lethal concentration and the fishes are
exposed to it for a period of 96 hours during which wide range of behavioural abnormalities are evidenced like general
hyperactivity, surfacing activity, hyper-opercular activity, and erratic swimming pattern. It is followed by loss of balance
and convolutions. One fifth of the lethal concentration is taken (i.e., 10 ppm) as sub-lethal concentration and fishes are
exposed to it for a period of 15 days during which growth, behaviour, oxygen consumption, histopathology, hematology
and genotoxicity are studied. Negative growth performance is observed with insignificant length increment up to 0.24 %
and significant weight reduction up to -2.38 %. Wide range of behavioural abnormalities are evidenced which includes,
erratic swimming, hyperactivity, surfacing activity and depression in appetite. Besides, general body discolouration and
haemorrhage are observed as well. Rate of oxygen consumption showed a time dependant decrease which ranged up to
-49.10%. Gills of the fishes are shown to have conspicuous histopathological alterations like lamellar necrosis, lamellar
fusion, lamellar erosion, epithelial lifting and epithelial swelling. Key-words- Bioindicator, L. rohita, Zinc sulphate, Growth, Behaviour, Oxygen Consumption, Histopathology
Effects of Fungicides for Non Target Fungi Alternaria cassiaeIJEAB
The fungicides are used to control of pathogenic fungi in several tilth but they can affect negatively the microorganisms diversity of soil. The aim of this research was to evaluate the toxicity and environmental risk of tebuconazoles: captan, tebuconazole and the mixture chlorothalonil + propamocarb hidrochloride for fungi Alternaria cassiae. Each fungicide were performed three experiments in completely randomized design with three repetitions and the growth was evaluated daily. Inhibition concentration (IC50;7d) of tebuconazole was 3.49 mg L-1, the captan was 47.36 mg L-1 and of mixture chlorothalonil + propamocarb hidrochloride, 64.04 mg L-1. Tebuconazole is classified as moderately toxic and sensitivity, captan, low toxicity and sensitivity and the mixture, non toxic and insensitive but only captan showed possibility of adverse effect for A. cassiae.`
Removal of Cr (VI) Through the Use of the Agroindustrial Residue of the Perse...CrimsonpublishersMCDA
We analyzed the Chromium (VI) removal capacity in aqueous solution by the Persea americana biomass, using the diphenyl carbazide method to evaluate the metal concentration. Biosorption at different pH (1, 2, 3, and 4) was evaluate for different times. We too studied the effect of temperature in the range of 28 to 60 °C and the removal at different initial concentrations of Cr (VI) of 200 to 1000mg/L. Therefore, the highest biosorption of the metal (50mg/L) occurs within 270 minutes, at pH of 1.0 and 28 °C. According to temperature, the highest removal was observing at 60 °C, in 45 minutes, when the metal is completely adsorbed. At the analyzed concentrations of Cr (VI), fungal biomass, showed excellent removal capacity, besides it removes efficiently the metal in situ (100% removal in earth and water contaminated, after 5 and 6 days of incubation, 5 and 10g of biomass, 10g of earth and 100mL of water; so, it can be used to eliminate it from industrial wastewater.
https://crimsonpublishers.com/mcda/fulltext/MCDA.000570.php
For more open access journals in Crimson Publishers please click on link: https://crimsonpublishers.com
For more articles on journal of agronomy and crop science please click on below link: https://crimsonpublishers.com/mcda/
Abstract— Biofuel production from microalgae biomass appears as a promising long term alternative. Dunaliella tertiolecta is a microalgae with high tolerance to salinity, temperature, and light, making it relatively easy to grow. The aim of this study was to establish a pilot-scale culture to evaluate the biomass yield and bioethanol production. The cell culture of D. tertiolecta was started in 20 ml tubes and escalated to 20 L containers. The biomass yield was 0.153 g L-1 of dry basis (db) and its characterization showed protein (37% db) as major component followed by carbohydrates (35.6), lipids (13% db) and ash (6.5%). The carbohydrate fraction was composed of starch (27.1% db) and fiber (8.5 %) and its neutral sugar characterization yield glucose (91% molar). The main components of the lipid fraction were linolenic and palmitic acids. The biomass was subjected to an acid pre-treatment for the saccharification of complex carbohydrates, and the hydrolyzed biomass was fermented by Saccharomyces cerevisiae. It was possible to produce 0.615 ml g-1 of ethanol. In conclusion, D. tertiolecta has the potential for bioethanol production, making it a promising option for the biofuels future.
The present study intended to compare the efficiency of the wetland plants Phragmites australis (cav.)
Trin. ex Steudel and Cyperus papyrus L. for the accumulation of heavy metals. Maximum accumulation
of the heavy metals Pb (132.5-175 μg/g DW), Zn (97.5-100 μg/g DW) and Cr (80.5-90 μg/g DW) was
recorded in roots of the two wetland plants C. papyrus and P. australis, respectively. Cadmium showed
the lowest metal accumulation in the tissues of both plants (0.55-5.5 μg/g DW). C. papyrus roots
accumulated higher levels of most metals than those of P. australis. Heavy metals were shown to be not
only accumulated in roots of both plants but also were translocated to the shoots and accumulated in the
harvestable plant parts. The results showed variation in the levels of the heavy metals accumulated in the
different parts of C. papyrus and P. australis, in spite of being planted at the same site and subjected to
the same conditions. The potential use of Phragmites australis and Cyperus papyrus in phytoremediation
is also discussed.
ABSTRACT- The development of human civilization throughout history has led to growing disruption of the natural
balance and the occurrence of different types of pollution. Environmental pollution with petroleum and petrochemical
products has been recognized as significant and serious problem. Diesel engine oil, which is one of the major products of
crude oil, constitutes a major source of pollution in our environment. Therefore diesel engine oil can enter into the
environment through wrecks of oil tankers carrying diesel oil, cleaning of diesel tanks by merchants, war ships carrying
diesel oil and motor mechanics. In present study the microorganisms utilising petrol and diesel oil as carbon source were
isolated and investigation of their characteristics towards the production of polyhydroxyalkanoates (PHA), which is now a
days well known as biodegradable polymer.
Key Words- Petrol and Diesel oil contamination, Bioremediation, Biodegradable bacterial polymer, Sudan
Black B staining, 16sr RNA sequencing
his study investigated the microbial community in a full scale anaerobic baffled reactor and sequencing batch reactor system for oil-produced water treatment in summer and winter. The community structures of fungi and bacteria were analyzed through polymerase chain reaction–denaturing gradient gel electrophoresis and Illumina high-throughput sequencing, respectively. Chemical oxygen demand effluent concentration achieved lower than 50 mg/L level after the system in both summer and winter, however, chemical oxygen demand removal rates after anaerobic baffled reactor treatment system were significant higher in summer than that in winter, which conformed to the microbial community diversity. Saccharomycotina, Fusarium, and Aspergillus were detected in both anaerobic baffled reactor and sequencing batch reactor during summer and winter. The fungal communities in anaerobic baffled reactor and sequencing batch reactor were shaped by seasons and treatment units, while there was no correlation between abundance of fungi and chemical oxygen demand removal rates. Compared to summer, the total amount of the dominant hydrocarbon degrading bacteria decreased by 10.2% in anaerobic baffled reactor, resulting in only around 23% of chemical oxygen demand was removed in winter. Although microbial community significantly varied in the three parallel sulfide reducing bacteria, the performance of these bioreactors had no significant difference between summer and winter.
YELLOW OLEANDER (THEVETIA PERUVIANA) SEEDS FOR HUMAN FOOD IN KENYApaperpublications3
Abstract:The Yellow oleander (Thevetia peruviana), is a potential oil seed and a good alternative source of nutrition for food and animal feeds. The seeds of Yellow oleander from four geographical regions (Busia, Bondo, Thika (JKUAT) and Mombasa districts) in Kenya were subjected to a nutritional value study. The oil and the defatted seed cake were analyzed for food values (fatty acids, proteins, minerals, fibre, and carbohydrates). Fatty acid characterization of the oil was done by GC. Minerals analysis was performed using AAS and flame photometer. The crude protein content of the defatted cake was determined by semi-micro Kjeldahl method. Carbohydrates values were determined by difference. Data analysis was done by SPSS program. The results showed that the nutritional values of these seeds were similar to those of other common oil seeds and did not depend on the climatic regions.
Characterization of leachates of the special handling wastes with different s...inventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
In a pot culture (2011), aerosols of oxidized nitrogen (NaNO2) @20kgha-1yr-1 (≈200 ppm), reduced nitrogen (NH4Cl) @10kg-1hayr-1 (≈100 ppm) and distilled water (control) were sprayed (1500 cm3plant-1) weekly at different days after sowing (DAS) to study their impacts on physiology of rice varieties (Bishnuprasad, Kanaklata, Joymati, Jyotiprasad and Mulagavaru). In a field trial (2012), the simulated N-aerosols @ 20 & 40 kg ha-1y-1 of each (1000 cm3m-2) along with a control were misted to population of the rice variety, Kanaklata at four different growth stages viz., germination and tillering (0-30 DAS), maximum tillering, (30-60 DAS), panicle initiation (60-90 DAS) and reproductive development (90-120 DAS). In both pot and field experiments, the N- aerosols brought about wide differences in net photosynthesis rates, nitrate reductase activity, nitrogen use efficiency (NUE), membrane permeability in the crop. The aerosols with lower doses at earlier growth stages influenced NUE and economic yield of the crop varieties. Mechanisms of altering membrane permeability either by depletion of Ca2+, or acceleration of peroxidase activity of cell in presence of the aerosols have been elucidated.
Bioremediation Potentials of Hydrocarbonoclastic Bacteria Indigenous in the O...IJLT EMAS
Hydrocarbon pollution Remediation by Enhanced
Natural Attenuation method was adopted to remediate the
hydrocarbon impacted site in Ogoniland Rivers State, Nigeria .
The research lasted for 6 months. Samples were collected at
monthly intervals . samples were collected intermittently
between Feb 2019 to July 2019 . Mineral salt medium containing
crude oil was used as a sole source of carbon and energy for the
isolation of hydrocarbonoclastic bacteria. Samples were
collected from the four (4) local government that made up
Ogoniland and they includes Khana(k), Gokana (G),Tai (T),
Eleme (E) and transported immediately to the laboratory for
analysis. The microbial and physicochemical properties of the
soil samples varied with the different local government areas.
Seven bacteria genera were isolated from the samples from the
four locations, viz, Pseudomonas, Lactobacter, Micrococcus,
Arthrobacter, Bacillus, Brevibacterium and Mycobacterium
were isolated and identified. the seven isolate were indigenous in
the study area. Nutrient were added to identified plots of
hydrocarbon pollution polluted site within the four local
government and they were able degrade hydrocarbon within a
short of period of time. Reassessment of physicochemical
parameter impacted site was used to judge the bioremediation
potentials of microorganism
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
"Protectable subject matters, Protection in biotechnology, Protection of othe...
Dempsterand sommerfeld1998
1. J. Phycol. 34, 712–721 (1998)
EFFECTS OF ENVIRONMENTAL CONDITIONS ON GROWTH AND LIPID
ACCUMULATION IN NITZSCHIA COMMUNIS (BACILLARIOPHYCEAE)1
Thomas A. Dempster 2 and Milton R. Sommerfeld
Department of Plant Biology, Arizona State University, Box 871601, Tempe, Arizona 85287-1601
ABSTRACT pogenic microalgae as the raw material for renewa-
Microalgae from natural saline habitats in the south- ble alternative liquid fuel sources.
western United States were isolated and screened for rapid Accumulation of large intracellular neutral lipid
growth potential and ability to store intracellular neutral reserves in microalgae has been noted by several in-
lipid, a precursor for renewable liquid fuel sources. After vestigators (Fogg and Collyer 1953, Milner 1953,
preliminary screening of isolated strains, Nitzschia com- Opute 1974b). Triglyceride accumulation ranging
munis (Rabenhorst) was selected for optimization of from 40% to 80% of cell dry weight was reported in
growth rate and lipid yield. Nitzschia communis was the diatom Nitzschia palea (Opute 1974a). Hydrocar-
subjected to two media types (SERI I, II) with different bons in marine phytoplankton (Blumer et al. 1971)
major ion compositions designed to mimic natural saline and fatty acid composition of various microalgae
groundwater aquifers in the arid Southwest. Growth rates have also been studied (Milner 1948, Otsuka and
were determined through 4 days of logarithmic growth, fol- Morimura 1966, Fisher and Schwarzenbach 1978,
lowed by 2 days of physiological stress (nitrogen depriva- Ben-Amotz et al. 1985). These microalgal derivatives
tion) and subsequent measurement of neutral lipid accu- are suitable precursors for the production of various
mulation. Poststress intracellular neutral lipid increases fuels. Triglycerides, hydrocarbons, and fatty acids
were documented by utilizing the fluorochrome Nile Red may be transformed into gasoline and diesel fuel
with fluorometric analysis and epifluorescent microscopy. substitutes via catalytic conversion and transesterifi-
Growth rate was slightly higher in SERI Type I medium, cation (McIntosh 1985b).
whereas lipid yield was higher in SERI Type II medium. The southwestern United States has been consid-
Rapid growth and appreciable lipid yields were observed ered the most appropriate region to concentrate mi-
over a broad range of temperatures (20Њ–30Њ C) and spe- croalgal outdoor mass-culture efforts (Johnson
cific conductances (10–70 mS·cmϪ1). The highest lipid 1987). This region offers favorable temperatures,
yields were observed at elevated conductances (between 40 high levels of year-round incident solar radiation,
mS·cmϪ1 and 70 mS·cmϪ1). Substitution of individual salt large expanses of unpopulated flat land, and a large
concentrations from SERI Type II into SERI Type I me- supply of water from natural saline groundwater
dium indicated that increased lipid yield in Type I medium aquifers that is unsuitable for human and livestock
was associated with a reduction in MgCl2 concentration. consumption, as well as other industrial and agri-
cultural uses.
Key index words: alternative liquid fuel; microalgae; To be exploited, microalgal candidates must pos-
neutral lipid; Nitzschia communis; renewable liquid sess certain desirable characteristics. They must ex-
fuel; storage lipid; triolein hibit rapid growth rates and appreciable lipid yields.
These organisms must also be tolerant of the ex-
The use of microalgae for a potential renewable treme environmental conditions found in the arid
liquid fuel source was first proposed by Meier Southwest and possess a life cycle that permits con-
(1955). The concept arose from earlier work de- tinuous culturing (Neenan et al. 1986).
signed to examine microalgal mass culturing in the The objective of this study was to evaluate the ef-
production of high protein foods and waste water fects of media type, temperature, specific conduc-
treatment (Burlew 1953). tance, and nutrient deficiency-induced stress on
The energy crisis and the Arab oil embargo dur- growth and neutral lipid production in the microal-
ing the early 1970s stimulated many countries to in- ga Nitzschia communis.
vestigate renewable alternative energy sources (Mc-
MATERIALS AND METHODS
Intosh 1985a). Oil shortages and reports that many
conventional hydrocarbon fuel sources (i.e. fossil Culture conditions. Nitzschia communis (Strain 3013, ASU Culture
Collection) was collected in 1985 from the Pecos Basin (Lat.
fuel reserves) might be depleted early in the 21st 33Њ20Ј12Љ, Long. 104Њ19Ј54Љ) in Bottomless Lakes State Park, Cha-
century prompted the Department of Energy vez County, New Mexico (Tyler 1989).
(DOE) and the Solar Energy Research Institute Two basic media (SERI Types I and II) were used that mim-
(SERI) to initiate the Aquatic Species Program icked the natural desert groundwater conditions in the south-
western United States (Barclay et al. 1988). The composition for
(ASP) in 1979 (Neenan et al. 1986). The ASP was a range of conductances (10–70 mS·cmϪ1) of SERI media is
designed to determine the feasibility of utilizing li- shown in Table 1. All media were enriched with trace metals,
vitamins, iron-EDTA, urea, sodium meta-silicate, and monobasic
potassium phosphate (Tyler 1989).
1 Received 12 August 1996. Accepted 30 March 1998. Stock cultures were maintained in both culture media (55
2 Author for reprint requests; e-mail dempster@asu.edu. mS·cmϪ1) at 25Њ C. Flasks were kept in a Percival incubator (Mod-
712
2. LIPID ACCUMULATION IN N. COMMUNIS 713
TABLE 1. SERI Types I and II media composition for conductances ranging from 10 mS·cmϪ1 to 70 mS·cmϪ1.
Salts Type I/II Type I/II Type I/II Type I/II Type I/II
(g·LϪ1) (10) (25) (40) (55) (70)
CaCl2·2H2O 0.00/0.037 3.93/0.037 5.62/0.037 7.61/0.037 8.43/0.037
MgCl2·6H2O 4.11/1.95 11.84/3.03 22.79/3.92 35.31/4.36 42.23/4.23
Na2SO4 0.00/2.67 2.93/5.87 3.31/15.72 3.71/23.31 3.62/28.36
KCl 0.19/0.47 0.41/0.97 0.66/2.03 0.96/3.04 1.19/3.67
NaHCO3 0.18/1.21 0.17/2.32 0.17/2.86 0.17/3.23 0.17/3.25
NaCl 2.12/0.23 3.85/0.88 9.13/1.23 13.02/1.49 16.04/1.53
CaSO4 1.69/1.51 0.00/8.08 0.00/12.96 0.00/20.59 0.00/26.08
el I-35LLVL; Percival, Boone, Iowa) in a 12L:12D photoperiod 6 nm, bandwidth 40 Ϯ 8 nm). Standard lipid curves were pre-
with cool white fluorescent tubes at a photon flux density of ϳ200 pared using dilutions of Triolein Standard (Sigma Diagnostics, St.
mol·mϪ2·sϪ1. Louis, Missouri) and the Nile Red staining technique (Greenspan
Experimental procedure. Initial optical densities (absorbances) of et al. 1985, Cooksey et al. 1987).
ca. 0.002 were attained by transferring aliquots of logarithmically Variables and SERI media alterations. The effects of media type
growing cultures into sterile 50-mL flasks at the onset of each (SERI I and II), temperature, and specific conductance on
experiment. A 3-mL aliquot from each experimental culture was growth and lipid yield were collectively screened on a thermogra-
immediately subjected to analysis in a Beckman Model DU-64 dient plate with a matrical design that allowed simultaneous ob-
spectrophotometer (Beckman Instruments, Inc., Fullerton, Cali- servation of up to 36 treatments and the generation of contour
fornia) at 750 nm to ensure uniform cell densities. plots using Sigma Plot (version 3.0). A range of temperatures
Typical experiments had a duration of 6 days. Growth rates from 10Њ to 35Њ C in 5Њ C increments and a range of specific
were monitored during the first 4 days (day 0–day 4). Prestress conductances from 10 mS·cmϪ1 to 70 mS·cmϪ1 in 15 mS·cmϪ1
intracellular neutral lipid content was measured at the end of day increments were examined.
4, and the cultures were pelleted in 15-mL centrifuge tubes using Substitutions of individual salt concentrations from Type II into
an MSE Super-Minor centrifuge (VWR Scientific, San Francisco, Type I medium were performed to determine whether these sub-
California) (1500 ϫ g). Supernatant was poured off, and the cells stitutions contributed to an increase in growth and lipid produc-
were resuspended in nutrient-depleted media. The process was tion (Table 2). For each substitution, temperature was main-
repeated to minimize carryover of existing nutrient-replete me- tained at 25Њ C and pH was found to only vary from 7.2 to 7.5,
dia. During the last 2 days of each experiment, cultures were with the exception of sodium carbonate substitution, which in-
subjected to nitrogen deprivation. Poststress lipid accumulation creased the medium pH to 8.17. The diatom was also subjected
was measured again on day 6. to a gradation of MgCl2 concentrations, from 4.36 g·LϪ1 to 35.31
Growth characterization. Optical densities were obtained at 24-h g·LϪ1 (control) in Type I medium.
intervals from day 0 (time of inoculation) to day 4 for cultures in Statistical analyses. One-way ANOVA was used to determine
logarithmic growth and on day 6 (for cultures grown under whether significant differences existed between growth rates and
stressed conditions) to determine whether a relationship existed lipid yields from exposure to different environmental parameters.
between growth and lipid accumulation. Growth rates were cal- Tukey multiple comparison tests were used to determine which
culated from optical densities and expressed in terms of dou- treatments were significantly different when ANOVA revealed sig-
blings per day (Sorokin 1973). nificant differences.
Lipid yield characterization. Epifluorescent microscopy and the
fluorochrome Nile Red were used to provide photomicrographic RESULTS
evidence of intracellular neutral lipids (Cooksey et al. 1987).
Prestress lipid yields were determined on day 4 after the loga- Growth. The highest cell density observed had an
rithmic growth period. Poststress lipid accumulation was mea- optical density of 0.076, which corresponded to ca.
sured on day 6 following 2 days of nitrogen deprivation. For both
pre- and poststress determination of lipid yield, a 4-mL aliquot
5 ϫ 105 cells·mLϪ1. A linear relationship existed be-
from each culture was subjected to fluorometric analysis. The tween cell numbers and culture optical density.
cells were stained with 50 L of Nile Red (10 mg Nile Red·100 SERI media type. Growth of N. communis, on aver-
mLϪ1 acetone). Analysis was completed 15 min after staining us- age, was slightly higher in Type I medium than in
ing a Turner Model 110 fluorometer (Turner, Mountain View, Type II (Figs. 1, 2). Higher growth rates were also
California) equipped with a blue lamp and high sensitivity door,
a Ditric Optics, Inc. (Hudson, Massachusetts), three-cavity narrow observed at lower temperatures (10Њ–20Њ C) in SERI
band excitation filter (center 480 Ϯ 2 nm, bandwidth 7.1 Ϯ 1.5 Type I medium (Fig. 1), whereas slightly better
nm), and a wide band interference emission filter (center 550 Ϯ growth occurred at higher temperatures (25Њ–35Њ C)
TABLE 2. Composition of SERI Type I medium at 55 mS·cmϪ1 specific conductance and altered Type I media with substitutions of major ion concen-
trations from SERI Type II medium.
Major ions (g·LϪ1)
Medium CaCl2 MgCl2 Na2SO4 KCl NaHCO3 NaCl Na2CO3
1 Control (I/55) 7.61 35.31 3.71 0.96 0.17 13.02 0.00
2 ϪCaCl2 0.037 35.31 3.71 0.96 0.17 13.02 0.00
3 ϪMgCl2 7.61 4.36 3.71 0.96 0.17 13.02 0.00
4 ϩNa2SO4 7.61 35.31 23.31 0.96 0.17 13.02 0.00
5 ϩKCl 7.61 35.31 3.71 3.04 0.17 13.02 0.00
6 ϩNaHCO3 7.61 35.31 3.71 0.96 3.23 13.02 0.00
7 ϩNaCl 7.61 35.31 3.71 0.96 0.17 20.59 0.00
8 ϩNa2CO3 7.61 35.31 3.71 0.96 0.17 13.02 1.49
3. 714 THOMAS A. DEMPSTER AND MILTON R. SOMMERFELD
FIG. 1. Growth rates (doublings·day Ϫ1) ob-
served on the thermogradient plate for N. commu-
nis cultured in SERI Type I medium over a range
of temperatures (10Њ–35Њ C) and specific conduc-
tances (10–70 mS·cmϪ1).
FIG. 2. Growth rates (doublings·dayϪ1) ob-
served on the thermogradient plate for N. com-
munis cultured in SERI Type II medium over a
range of temperatures (10Њ–35Њ C) and specific
conductances (10–70 mS·cmϪ1).
4. LIPID ACCUMULATION IN N. COMMUNIS 715
FIG. 3. Epifluorescent micrographs of N. communis taken (a) prior to nitrogen deprivation (prestress), and (b) after 2 days of nitrogen
deprivation (poststress). Scale bars ϭ 10 m. Note the multiple small neutral lipid bodies comprising only a small portion of the total
cell volume in (a) and the two or three large lipid deposits comprising more than two-thirds of the total cell volume in (b).
in Type II medium (Fig. 2). However, four of the higher in Type II (113 mg·LϪ1) than in Type I me-
five highest growth rates were observed in Type II dium (37 mg·LϪ1)(Figs. 4, 5).
medium (Fig. 2). Temperature. Optimal temperature for prestress
Temperature. The highest growth rates on the ther- yield was between 25Њ and 30Њ C in both Type I and
mogradient plate for Type I and II media both oc- Type II media. The highest poststress lipid yields
curred at 30Њ C (Figs. 1, 2). In addition, N. communis occurred at 25Њ C, although substantial yields were
exhibited rapid growth over a broad range of tem- also observed at 20Њ and 30Њ C (Figs. 4, 5).
peratures (20Њ–30Њ C) in both media types. The tem- Specific conductance. Optimal prestress yield oc-
perature extremes (10Њ and 35Њ C) resulted in re- curred at a specific conductance of 25 mS·cmϪ1 in
duced growth in Type I medium (Fig. 1), whereas Type I and 40 mS·cmϪ1 in Type II medium. Post-
almost no growth was observed at 10Њ or 15Њ C in stress lipid yield was greatest at ca. 55 mS·cmϪ1 in
Type II medium (Fig. 2). Type I and between 40 and 55 mS·cmϪ1 specific con-
Specific conductance. The highest growth rates on ductance in Type II medium (Figs. 4, 5).
the thermogradient plate were 2.14 doublings per Substitution of salt concentrations. Individual salt
day observed at 55 mS·cmϪ1 in Type I medium and concentrations were substituted from Type II into
2.25 doublings per day at 40 mS·cmϪ1 in Type II. Type I medium (Table 2) to determine whether spe-
However, growth was not influenced as much by the cific salt concentrations affected lipid yield.
range of specific conductances as it was by the range Growth was slightly higher than, but not signifi-
of temperatures investigated. cantly different from, the control in all substitutions
Lipid yield. Epifluorescent microscopy, utilized that increased salt concentrations (Fig. 6). Cultures
with the fluorochrome Nile Red, revealed that neu- subjected to reduced major salt concentrations (i.e.
tral lipids were a major form of carbon storage in CaCl 2 and MgCl 2 ) exhibited significantly lower
N. communis. Prior to nitrogen deprivation (pre- growth rates than control cultures.
stress), rapidly growing cells exhibited multiple (10– The average prestress lipid yield increased as
15) small neutral lipid bodies comprising a small NaHCO3 concentration increased from 0.17 to 3.23
portion (ca. 10%–20%) of total cell volume (Fig. g·LϪ1 and was significantly higher than the prestress
3a). Storage lipid bodies increased in size and coa- control with yields of 45.83 and 12.76 mg·LϪ1, re-
lesced after 2 days of nitrogen deprivation (post- spectively (Fig. 7a). Other substitutions did not re-
stress), creating two to three large neutral lipid de- sult in prestress yields that were statistically different
posits that made up 60%–75% of total cell volume from the control.
(Fig. 3b). A significantly higher poststress yield (142.36
SERI media type. Pre- and poststress lipid yields in compared to 50.38 mg·LϪ1) was observed when
N. communis were consistently higher in SERI Type MgCl2 concentration was reduced from the control
II medium than in Type I. Average prestress yields concentration of 35.31 to 4.36 g·LϪ1 (i.e. 0.37–
were almost four times higher in Type II (38 0.046M) (Fig. 7b).
mg·LϪ1) than in Type I medium (10 mg·LϪ1). Av- When MgCl2 concentration in Type I medium at
erage poststress yields were more than three times 55 mS·cmϪ1 was systematically reduced from 35.31
5. 716 THOMAS A. DEMPSTER AND MILTON R. SOMMERFELD
FIG. 4. Poststress lipid yields (mg·LϪ1) observed
on the thermogradient plate for N. communis cul-
tured in SERI Type I medium over a range of tem-
peratures (10Њ–35Њ C) and specific conductances
(10–70 mS·cmϪ1).
FIG. 5. Poststress lipid yields (mg·LϪ1) observed
on the thermogradient plate for N. communis cul-
tured in SERI Type II medium over a range of tem-
peratures (10Њ–35Њ C) and specific conductances
(10–70 mS·cmϪ1).
6. LIPID ACCUMULATION IN N. COMMUNIS 717
FIG. 6. Comparison of growth rates in SERI
Type I medium (control) and SERI Type I medium
with substitutions of individual salt concentrations
from SERI Type II medium (mean Ϯ 1 SD, n ϭ 3).
Individual salt concentration increases and decreas-
es are denoted by ‘‘ϩ’’ and ‘‘Ϫ’’, respectively. The
x-axis labels represent the following: 1 ϭ I/55, 2 ϭ
ϪCaCl2, 3 ϭ ϪMgCl2, 4 ϭ ϩNa2SO4, 5 ϭ ϩKCl, 6
ϭ ϩNaHCO3, 7 ϭ ϩNaCl, and 8 ϭ ϩNa2CO3.
to 4.36 g·LϪ1, prestress yields ranged from 5.39 DISCUSSION
mg·LϪ1 (at 4.36 g·LϪ1) to 18.37 mg·LϪ1 (at 28 g·LϪ1), Growth. Nitzschia communis grew well in both SERI
but were not statistically different (Fig. 8a). Howev- media. Growth was, on average, only slightly higher
er, reduction in MgCl2 concentration resulted in in- in Type I medium than in Type II. Sommerfeld and
creased poststress neutral lipid yield. A concentra- Ellingson (1987) and Sommerfelt et al. (1987) also
tion of 12 g·LϪ1 stimulated a significantly higher observed no significant differences between growth
poststress lipid yield (200.26 mg·LϪ1) than other in Type I and II media by 62 strains of microalgae.
concentrations (Fig. 8b). In contrast, Amphora sp. and Ankistrodesmus sp. ex-
FIG. 7. Comparison of lipid yields (a) before
(prestress), and (b) after (poststress) nitrogen deple-
tion in SERI Type I medium (control) and SERI Type
I media with substitutions of individual salt concen-
trations from SERI Type II medium (mean Ϯ 1 SD,
n ϭ 3). Individual salt concentration increases and
decreases are denoted by ‘‘ϩ’’ and ‘‘Ϫ’’, respectively.
The x-axis labels represent the following: 1 ϭ I/55, 2
ϭ ϪCaCl2, 3 ϭ ϪMgCl2, 4 ϭ ϩNa2SO4, 5 ϭ ϩKCl, 6
ϭ ϩNaHCO3, 7 ϭ ϩNaCl, and 8 ϭ ϩNa2CO3.
7. 718 THOMAS A. DEMPSTER AND MILTON R. SOMMERFELD
FIG. 8. Effect of reduced magnesium chloride
concentrations in SERI Type I medium on (a) pres-
tress, and (b) poststress lipid yield (mean Ϯ 1 SD, n
ϭ 5).
hibited significantly higher growth rates in SERI growth temperature for most microalgae under con-
Type II than Type I medium (Barclay et al. 1985). sideration in the ASP ranged between 20Њ and 35Њ
Barclay et al. (1987) also reported optimal growth C (Barclay et al. 1985, Tadros 1985, Johansen et al.
for two Amphora spp. and one Monoraphidium sp. in 1987).
Type II medium and optimal growth for one Cyclo- Nitzschia communis satisfied another desirable
tella sp. in Type I. Growth in SERI media (Type I or characteristic for potential mass-culture efforts by
II) appeared to vary significantly among genera, spe- being euryhaline with good growth over a conduc-
cies, and strains of microalgae (Barclay et al. 1986). tance range from 10 to 70 mS·cmϪ1. Tolerance of
Growth in the two SERI media also differed N. communis to a wide range of specific conduc-
among algal classes and divisions. Type II medium tances would allow this strain to grow rapidly in most
supported growth of all diatoms, but Type I often of the natural saline groundwater aquifers in the
inhibited diatom growth (Tadros 1987). Ellingson Southwest. In a survey of 106 saline waters in Ari-
et al. (1989) reported that cyanophyte and chryso- zona, California, New Mexico, Texas, and Utah, con-
phyte growth was equivalent in both SERI media, ductance averaged 22.7 mS·cmϪ1 (Ellingson and
but chlorophyte growth was significantly higher in Sommerfeld 1992).
Type II. Optimal specific conductance for growth also var-
Nitzschia communis grew rapidly over a range of ies substantially between microalgal genera, species,
temperatures from 20Њ to 30Њ C, with the highest and strains, as well as within strains, with respect to
growth rates observed at 30Њ C. Rapid growth in el- type of medium. This suggests that total dissolved
evated temperatures (thermophily) and over a salts may not be as important as the relative pro-
broad range of temperatures (eurythermy) are de- portions of specific ions. For example, optimal
sirable characteristics for microalgae to possess to growth for Cyclotella cryptica was observed at 25
have potential for mass culture (Neenan et al. mS·cmϪ1 in SERI Type I and at 40 mS·cmϪ1 in Type
1986). II (Johansen et al. 1987). Barclay et al. (1986) listed
Optimal temperature for growth, like media type numerous microalgal strains that required different
(I, II), is genera, species, and even strain specific conductances of each SERI medium for optimal
(Burlew 1953, Barclay et al. 1986). Guillard and Ry- growth. Conversely, the same conductance for op-
ther (1962) isolated strains of Cyclotella nana from timal growth in both SERI media has also been re-
near-shore and offshore locations and reported tem- ported (Barclay et al. 1985, Sommerfeld et al. 1987).
perature optima of 25Њ and 15Њ C, respectively. Sim- For example, Amphora sp. and Ankistrodesmus sp.
ilar to N. communis, Navicula saprophila exhibited op- grew best at 25 mS·cmϪ1 in both SERI media (Bar-
timal growth at 30Њ C (Chelf et al. 1987). Optimal clay et al. 1985). In addition, some strains grew rap-
8. LIPID ACCUMULATION IN N. COMMUNIS 719
idly over a broad range of conductances in both me- two- to threefold increases in the lipid content of
dia (Barclay et al. 1986, Chelf et al. 1987, Tadros chlorophytes, whereas both increases and decreases
1987). were observed in diatoms after nitrogen deprivation.
Lipid yield. Intracellular neutral lipid production Barclay et al. (1985) reported that lipid content
in N. communis was significantly higher in SERI Type more than doubled in Amphora sp., but increased
II than Type I medium. Ellingson et al. (1989) also only slightly in Ankistrodesmus sp. after nitrogen de-
reported that mean lipid yield in Type II was nearly privation. Similarly, postnitrogen stress lipid yield in-
twofold higher than in Type I for 102 strains ex- creased for approximately 10 days in Cyclotella sp.,
amined. However, the optimal SERI media type for but fluctuated in Ankistrodesmus sp., Chlorella sp., and
lipid production also differed between genera, spe- Isochrysis sp. (Benemann and Tillett 1987).
cies, and strains of microalgae (Barclay et al. 1986, Neenan et al. (1986) reported that rapidly grow-
Johansen et al. 1987). ing microalgae consisted of 50%–70% membrane-
Although average lipid yield in N. communis was bound polar lipids, but shifted to a predominant
not significantly different at temperatures between neutral lipid composition (up to 60%) when de-
20Њ and 30Њ C, slightly higher lipid yields were ob- prived of nitrogen. Suen et al. (1987) reported a
served at 30Њ C. Others have shown that lipid yield metabolic shift in Nannochloropsis sp. from polar lip-
usually increased as temperature increased up to 35Њ id biosynthesis under nitrogen sufficiency to neutral
C (Johansen et al. 1987, Tadros 1987). Opute lipid biosynthesis under nitrogen deficiency. How-
(1974a) reported optimal fat synthesis in Nitzschia ever, both polar and neutral lipid yields increased
palea at 35Њ C, but a drastic reduction in lipid pro- after nitrogen or silicon deficiency in Chaetoceros sp.
duction at temperatures below 15Њ C and above 40Њ (Sriharan and Bagga 1987), Cyclotella sp., and Mon-
C. Chelf et al. (1987) observed total lipid increases oraphidium minitum (Sriharan et al. 1987). Cooksey
in Navicula saprophila as temperature increased from et al. (1989) proposed that nitrogen deficiency did
17Њ to 32Њ C. Polar and neutral lipid contents were not directly induce triglyceride synthesis in microal-
significantly higher for Chaetoceros sp., Cyclotella sp., gae but caused cell division to cease, which reduced
and Monoraphidium minitum when cultured at 30Њ C, intracellular energy demand on storage lipids. He
compared to 25Њ C (Sriharan and Bagga 1987, Sri- suggested that triglycerides are synthesized at the
haran et al. 1987). same rate throughout the cell cycle, and triglyceride
Although N. communis exhibited appreciable lipid accumulation varies in response to energy demand
yields over a wide range of specific conductances, at different stages of the cell cycle.
optimal specific conductance for lipid production Influence of major salts. Substitution of salt concen-
was between 40 and 55 mS·cmϪ1. Lipid yield was trations among the two media generally did not lead
usually higher in salt-tolerant microalgae as conduc- to increased neutral lipid storage in N. communis.
tance of SERI media increased (Barclay et al. 1986). However, neutral lipid production was noticeably in-
Increased lipid yield was observed as increased salt fluenced by specifically altering the MgCl2 concen-
concentration caused physiological stress in Botry- tration in the culture medium. Roessler (1989) re-
ococcus braunii and Isochrysis sp. (Ben-Amotz et al. ported that the activity of acetyl-CoA carboxylase
1985) and Chlorella sp. (Tadros 1985). (ACC), an enzyme utilized early in fatty acid synthe-
Nitrogen deprivation. Dramatic intracellular neutral sis, was dependent on the presence of divalent metal
lipid (triglyceride) increases occurred after nitrogen cations, especially magnesium (Mgϩϩ). Roessler ob-
deprivation. Both nitrogen deficiency, a decrease in served reduced ACC activity when manganese
the amount of available nitrogen, and nitrogen de- (Mnϩϩ) was the only divalent metal present and no
privation, the absence of nitrogen in culture media, ACC activity when only cobalt (Coϩϩ) was present.
have been closely related to increased lipid accu- This study has attempted to evaluate some of the
mulation in microalgae. For example, lipid produc- factors that may influence the growth and lipid yield
tion increased as nitrogen concentration decreased of a common diatom, Nitzschia communis, which may
in cultures of Chlorella vulgaris (Fogg and Collyer be a potential candidate for future efforts to develop
1953), Nitzschia palea (Opute 1974a), Ankistrodesmus alternative renewable liquid fuel sources. In the lab-
sp., Chlorella sp., Navicula saprophila (Chelf et al. oratory, N. communis exhibited rapid growth, appre-
1987), Chaetoceros sp. (Sriharan and Bagga 1987), Cy- ciable lipid yield, tolerance of extreme conditions
clotella sp., and Monoraphidium minitum (Sriharan et similar to those found in the arid southwestern Unit-
al. 1987) and Nannochloropsis sp. (Suen et al. 1987). ed States, and a life cycle that permitted continuous
The effect of nitrogen deficiency on lipid produc- culturing. Field operations will be necessary to de-
tion varies among and within algal divisions. Two termine whether N. communis exhibits outdoor
green algae exhibited increased lipid content in re- growth and lipid production characteristics compa-
sponse to nitrogen deficiency, whereas four cyano- rable to those observed in the laboratory.
bacteria did not show any significant changes in lip-
id composition when exposed to reduced nitrogen Barclay, B., Nagle, N. & Terry, K. 1987. Screening microalgae
concentrations (Piorreck et al. 1984). Shifrin and for biomass production potential: protocol modification
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Barclay, B., Nagle, N., Terry, K. & Roessler, P. 1985. Collecting perature, light intensity, and nutrient concentration dur-
and screening microalgae from shallow, inland saline hab- ing the continuous culture of Nitzschia closterium and Te-
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Institute, Golden, Colorado, pp. 52–68. SERI/CP-231–2700. Solar Energy Research Institute, Gold-
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BOOK REVIEW
J. Phycol. 34, 721–723 (1998)
MOLECULAR PHYLOGENY OF THE ALGAE
gins of Algae and Their Plastids. This superb book dis-
Bhattacharya, Debashish, ed. 1997. Origins of Algae cusses in great depth what research using the new
and Their Plastids. Springer, Wien. 287 pp. 270 DM molecular methods has revealed about the evolution
(approximately US$180.00), ISBN: 3-211-83036-7. of algae and their plastids in the decade since So-
gin’s first surprising phylogenetic trees were pub-
lished.
The construction of phylogenetic trees based on This is a weighty book. It contains 14 chapters
the sequence of the ribosomal RNA of the small sub- written by 34 authors and coauthors. Bhattacharya
unit (SSU) of eukaryotic ribosomes has revolution- has chosen young researchers, all molecular biolo-
ized the systematics of the algae. For me, this revo- gists actively working with the algae they discuss, to
lution began with Mitch Sogin’s classic 1987 and write the chapters. The chapters are all very detailed
1989 papers (Proc. Natl. Acad. Sci. USA [1987]84: and contain extensive bibliographies. The bibliog-
5823–5827; Science [1989]243:75–77), which showed raphies are outstanding, giving complete titles in
that Giardia lamblia was the earliest diverging eu- large, easy-to-read print, a feature those of us in the
karyotic lineage, an honor it still holds, although its older generation, who can barely read the refer-
lack of mitochondria is no longer considered prim- ences in Science and Nature, will especially appreci-
itive since it has recently been shown to contain the ate. The references are also up to date, a difficult
gene for chaperonin 60, a mitochondrial protein. feat to manage in a multiauthored book. The book
Slightly higher up the tree, trypanosomes and their was published in late 1997, and the bibliographies
close relative, Euglena gracilis, branched off together,
contain numerous 1996 references and even some
confirming Euglena’s distinctiveness from other al-
1997 ones. Although molecular evolution is a rap-
gae and lending credence to my hypothesis that Eu-
idly moving field, in no case am I aware of a major
glena obtained its chloroplasts secondarily from sym-
biotic green algae. Dictyostelium branched off next, 1997 or 1998 discovery that diminishes a chapter’s
but after that, the tree had a bushy top, with this importance. Bhattacharya has produced the right
crown radiation producing virtually all the other eu- book at the right time. I congratulate the publishers
karyotes. In this crown group, the chrysophyte alga on the very attractive format of the book and the
Ochromonas was on the same branch as the oomycete promptness with which it was published.
Achlya, a relationship phycologists had long suspect- I have only two small complaints. The chapters
ed because of the fine structure of their heterokont are not numbered. Authors do refer to other chap-
flagella. Dinoflagellates, to my surprise, were first ters by number, but usually by the wrong number.
cousins of the ciliates. I wouldn’t have been sur- Also, the book is only available in hardcover, even
prised if I had looked carefully at the fine structure though it was originally published as a supplement
of ciliates and seen the close similarity between their to Plant Systematics and Evolution, and there it was
alveolar sacs and the amphiesmal vesicles of dino- produced in softcover. Springer-Verlag should make
flagellates, but in those premolecular days, most the book available to everyone in softcover and at a
phycologists paid scant attention to protozoa and price more phycologists could afford.
fungi. Today’s molecular phylogenetic trees, how- This book has two main themes. In a number of
ever, clearly show that the ‘‘Algae’’ are a group of the chapters, the authors’ main concern is what mo-
unrelated protists and oomycete fungi, which have lecular sequences reveal about the evolution of the
acquired their chloroplasts either directly or indi- algal class discussed and how subclasses, orders, and
rectly. at times families are related to each other. The con-
Thus, I was very pleased to be asked to review clusions are usually based on SSU rRNA trees, but
Debashish Bhattacharya’s important new book, Ori- some chapters include protein-based trees where
11. 722 BOOK REVIEW
available. In the other chapters, the main concern role in earlier classifications of the green algae that
is the evolution of chloroplasts. Here, the crucial I suspect many morphologically oriented phycolo-
questions are: did a cyanobacterium become a chlo- gists will be unhappy with Friedl’s revisions. I feel
roplast only once or more than once (the consensus SSU rRNA data must be supported by other phylo-
is that this primary symbiosis occurred only once), genetic trees based on protein sequences or mito-
and how many times did chloroplasts arise second- chondrial genes before we discount ultrastructural
arily from a eukaryotic endosymbiont? In the two characteristics. Huss and Krantz’s short and emi-
groups where the symbiont’s nucleus persists, the nently readable chapter on the charophytes shows
cryptomonads and chlorarachniophytes, the authors that contrary to popular opinion, the Charales are
ask why the nucleomorph has persisted and what a distinct and ancient lineage within the group.
genes it contains. However, which of the other orders of the Charo-
In the first chapter, Bhattacharya describes con- phyta is the ancestor to land plants is still an open
cisely and clearly for readers such as myself the question.
three common methods of determining phyloge- The remaining chapters deal in large part with
netic trees from sequence data, namely distance, the evolution of chloroplasts in the algae. Start by
maximum parsimony, and maximum likelihood. I reading Delwiche and Palmer’s superb chapter,
suspect this chapter will also be useful to those start- ‘‘The origin of plastids and their spread via second-
ing to use these methods, for it gives the specific ary symbiosis.’’ This comprehensive chapter gives a
name of the computer programs one can buy to detailed and balanced discussion of the data for and
construct trees by each technique. against a single primary endosymbiosis forming the
Chapters that discuss primarily the evolutionary chloroplasts of the red and green algae as well as
relationships within a single class of algae are Tur- the cyanelles of the glaucocystophytes. They con-
ner’s on the cyanobacteria, Saunders and Kraft’s on clude that plastid sequence data support a mono-
the red algae, Saunders and coauthors’ on the di- phyletic origin, that mitochondrial data support
noflagellates, Druehl and colleagues’ on the brown monophyly of the red and green algae (no mito-
algae, Friedl’s on the green algae, and Huss and chondrial data are available for the glaucocystophy-
Kranz’s on the Charophyta. Although these chapters tes), and that the nuclear data are inconclusive.
will mainly be of interest to specialists in each group, They and Turner emphasize the need for much
they also contain enough general information to more data on the cyanobacteria, and both Turner
make them worthwhile reading for all phycologists and Delwiche and Palmer emphasize that although
interested in evolution. plastids appear as a monophyletic branch on the cy-
Turner’s chapter shows clearly that each of the anobacterial tree, this does not exclude the possi-
three known prochlorophytes, Prochloron didemni, bility that the same or two or more closely related
Prochlorothrix hollandica, and Prochlorococcus marinus, cyanobacteria could have separately given rise to pri-
belongs to a different subgroup of the cyanobacter- mary chloroplasts, what Palmer calls ‘‘cryptic poly-
ia. Whether chlorophyll b has evolved independently phyly.’’ Delwiche and Palmer continue with a con-
a number of times, as first believed, is made less cise description of all the algal groups which have
certain by the recent discovery that P. marinus has secondary chloroplasts, that is, chloroplasts that
both phycoerythrin and chlorophyll b, an observa- evolved from endosymbiotic eukaryotic algae. These
tion that raises the possibility of multiple pigment even include the Apicomplexa, for Iain Wilson and
losses. Donald Williamson have discovered that the malar-
I was disappointed that the chapter on red algal ial parasite Plasmodium has a secondary chloroplast.
evolution did not include a summary of current Wilson (Mol. Gen. Genet. [1994]243:249–252) has
knowledge on the Bangiophycidae, but instead the presented evidence that the plastid of Plasmodium
chapter referred the reader to Mark Ragan’s 1994 evolved from a symbiotic red alga, but Delwiche, in
paper on the topic (Proc. Natl. Acad. Sci. USA a recent paper (Science [1997]275:1485–1489) on
[1994]91:7276–7280). The big advantage of a com- another apicomplexan parasite, suggests the plastid
prehensive book like the present one is that it was originally a symbiotic green alga.
should collect all current data in one convenient Several very informative chapters extend the sec-
place. ondary endosymbiosis story. Fraunholz and col-
Friedl’s chapter on the evolution of the green al- leagues’ chapter on the cryptomonads show just
gae based on SSU rRNA sequences presents once how far our knowledge of cryptomonad nucleo-
again a new classification of the green algae, includ- morphs has advanced since Marcelle Gillott’s pio-
ing a new class, the Trebouxiophyceae. Friedl’s SSU neering study (J. Phycol. [1980]16:558–568) on nu-
rRNA data indicate that counterclockwise basal body cleomorph ultrastructure. The sequence of nucleo-
orientation, the phycoplast type of mitosis, and morph SSU rRNA shows that the symbiont that gave
probably also MLS rootlets are symplesiomorphic rise to the chloroplast was closely related to the red
characters, that is, similar primitive features that are algae. The authors have shown that the nucleo-
presently shared by independent lineages. Phyco- morph genome consists of three small chromo-
plasts and MLS rootlets have played such a major somes with a total length of 600 kb. A collaborative
12. BOOK REVIEW 723
project to sequence this genome is underway, and a Loeffelhardt and colleagues’ on the cyanelle ge-
number of genes have already been identified. nome of Cyanophora paradoxa are both essential
Goeff McFadden, in an excellent chapter written reading for anyone concerned with whether chlo-
with his usual flair, discusses the Chlorarachnioph- roplasts, including the cyanelles, are monophyletic.
yta, filose amoebae whose chloroplasts have finally Although the evidence presented in these two chap-
been shown by the sequence of the SSU rRNA of ters strongly suggests that only a single symbiotic
their nucleomorphs to have evolved from green al- event gave rise to the cyanelles of the glaucocysto-
gae. Surprisingly, the nucleomorphs of Chlorarach- phytes and the plastids of red and green algae, we
nion reptans also have three small chromosomes. still need more data. The enigmatic amoeba Pauli-
McFadden and his team are rapidly characterizing nella chromatophora, which contains two sausage-
these chromosomes. At the time he wrote the chap- shaped cyanelles, is not related to either the glau-
ter, he had shown that each chromosome is capped cocystophytes or to the red and green algae. If its
by telomeres and each has a ribosomal RNA cistron cyanelles are not simply symbiotic cyanobacteria but
interior to each telomere. He had also found eight true plastids (of all the cyanelles, those of Paulinella
protein genes, including heat shock protein 70, a most closely resemble free-living cyanobacteria), it
subunit of RNA polymerase, an RNA helicase, and seems very unlikely that these cyanelles arose from
a chloroplast protease. Although McFadden was the the same symbiotic event that gave rise to the other
first person to show by in situ hybridization that the cyanelles and the chloroplasts of red and green al-
plastid DNA of Toxoplasma, a close relative of Plas- gae. But more importantly, I would like to see data
modium, is located in a small spherical body, sur- on the plastid DNA of what Saunders calls typical
rounded, I believe, by three or four membranes, his dinoflagellate chloroplasts, plastids surrounded by
short chapter on the plastids of the Apicomplexa is three membranes that contain the unique soluble
not up to his usual standards. I recommend that peridinin–chlorophyll a-protein in addition to the
anyone interested in this fascinating story read Wil- peridinin–chlorophyll a/c light-harvesting protein,
son and Williamson’s excellent 1997 review (Micro- and a nuclear-coded form II RUBISCO, consisting
biol. Mol. Biol. Rev. [1997]61:1–16). of two large subunits only. Although the presence
The chloroplast chapter I found most interesting of three surrounding membranes suggests that these
and most original in the sense of being a new syn- chloroplasts have evolved from a secondary symbi-
thesis is that of Linda Medlin and her colleagues on osis, perhaps they did not. Possibly, they evolved di-
the phylogeny of the golden algae. This chapter rectly from a symbiotic prokaryote. If so, these plas-
draws together an immense amount of information tids have so many unique characteristics that they
on the heterokont groups and the haptophytes: his- easily could have arisen from a different symbiosis
tory of their nomenclature, morphology, pigments, than the one that gave rise to other primary chlo-
phylogenetic trees based on the sequences of SSU roplasts. Isolating and sequencing the plastid DNA
rRNA, actin, and the light-harvesting proteins as well of one of these typical dinoflagellate chloroplasts
as plastid phylogenetic trees based on three differ- should be a high priority for this generation of mo-
ent chloroplast genes, to answer a set of clearly de- lecular phycologists.
fined questions on the evolution of both the host This review is dedicated to the memory of Marcelle A. Gillott, an
cells and their chloroplasts. In brief, Medlin shows enthusiastic phycologist, a superb electron microscopist, and a
that the haptophytes and the pigmented hetero- loyal friend, who died tragically in a freak accident on November
konts are separate nonrelated groups. Each inde- 23, 1995.
pendently acquired its plastid from a eukaryotic sym- SARAH P. GIBBS
biont at or shortly before the Permian–Triassic Department of Biology
boundary. Each group endocytosed a different alga. McGill University
The two remaining chapters of the book, Bhatta- 1205 Dr. Penfield Avenue
charya and Schmidt’s on the Glaucocystophyta, and Montreal, Quebec H3A 1B1, Canada