- Oxford, Oxfordshire, United Kingdom
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ABSTRACT A dispersion/differential centrifugation (DDC) procedure was used to recover actinomycetes from a sandy soil. The efficiency of the procedure in recovering actinomycetes was monitored using tuberculostearic acid (TBSA). To... more
ABSTRACT A dispersion/differential centrifugation (DDC) procedure was used to recover actinomycetes from a sandy soil. The efficiency of the procedure in recovering actinomycetes was monitored using tuberculostearic acid (TBSA). To measure TBSA in soils and in the DDC extracts, an acid methanolysis procedure, used routinely for the extraction of fatty acid methyl esters from pure cultures, was modified to include a preliminary wash in chloroform: methanol. The modified methanolysis procedure extracted 104% of the TBSA from biomass added to soil. The recovery of actinomycetes, estimated from the recovery of TBSA (10-methyloctadecanoic acid) in the soil extract, was 41 ± 1.5% of that present in the whole soil. This compares favourably with values obtained for the recovery from sandy soils of biomarkers representative of the total biomass, namely phospholipid and adenosine triphosphate. The techniques outlined in this paper demonstrates the usefulness of the DDC procedure in enhancing the recovery of TBSA containing actinomycete propagules from soil and provides a simple chemical analysis by which different recovery procedures can be compared.
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Numerous studies have demonstrated the efficacy of bioremediation for enhancing oil removal but the ecological effect on shoreline biota is unclear. Therefore, a field experiment was designed at an intertidal sandflat in SW England to... more
Numerous studies have demonstrated the efficacy of bioremediation for enhancing oil removal but the ecological effect on shoreline biota is unclear. Therefore, a field experiment was designed at an intertidal sandflat in SW England to assess the effects of nutrient addition to oiled sediments on meio- and macrofauna for a period of up to 45 weeks. Natural assemblages were exposed to different types of experimental treatments (no oil, oil alone, oil treated with slow-release fertiliser or liquid fertiliser). Bioremediation stimulated the microbial population and increased oil biodegradation. This, however, did not result in faster recolonisation rates of fertilised versus non-fertilised oiled sediments. Mild effects of oil and bioremediation treatments on benthic fauna were observed, including short-term shifts in dominance patterns. Decreased abundance of dominant species in the oiled compared to unoiled sediments resulted in significantly higher evenness of benthic assemblages within the first 11 weeks of the experiment.
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Research Interests: Kinetics, Molecular Genetics, Multidisciplinary, Single cell analysis, Fluorescence in situ hybridization, and 14 moreEscherichia coli, Applied Environmental Microbiology, Bacteria, Pseudomonas putida, Cytochrome oxidase, Phenotype, Natural Environment, Genotype, Vibrio, Base Sequence, Digital Image, Ribosomal DNA, Oxidation-Reduction, and Molecular Sequence Data
Contamination of soils with heavy metal ions is a major problem on industrial and defense-related sites worldwide. The bioavailability and mobility of these contaminants is partially determined by the microbial biomass present at these... more
Contamination of soils with heavy metal ions is a major problem on industrial and defense-related sites worldwide. The bioavailability and mobility of these contaminants is partially determined by the microbial biomass present at these sites. In this study, we have assessed the effect of the addition of a mixture of toxic metal salts on the prokaryotic community of microcosms consisting of sandy-loam soil using direct molecular analysis of the recoverable eubacterial 16S rDNA molecules by polymerase chain reaction--denaturing gradient gel electrophoresis (PCR-DGGE) and limited phospholipid fatty acid analysis (PLFA). Addition of toxic metals (nonradioactive surrogates of Sr, Co, Cs, Cd) resulted in rapid (ca. 1 week) changes in the DGGE profile of the indigenous eubacterial community when compared with pristine controls. These changes were stable over the course of the experiment (8 weeks). No changes in the eubacterial population of control microcosms were detected. The major changes in community structure in metal-contaminated microcosms consisted of the appearance of four novel bands not detected in controls. Sequence analysis of these bands suggested that two organisms related to the genus Acinetobacter and two related to the genus Burkholderia carried a selective advantage over other indigenous eubacteria under heavy metal induced stress. The Burkholderia spp. were then cultured and further characterized using lipid analysis.
Research Interests: Microbiology, Medical Microbiology, Canadian, Heavy metals, Microbial genetic and drug resistance, and 8 morePolymerase Chain Reaction, Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis, Soil Microbiology, Burkholderia, Acinetobacter, Veterinary Sciences, Base Sequence, and Molecular Sequence Data
Research Interests: Phospholipids, Microbial diversity, Multidisciplinary, Logistic Regression, Phylogeny, and 17 moreFatty acids, Uranium, Gram Positive, Applied, Applied Environmental Microbiology, Polymerase Chain Reaction, Sulfate reducing Bacteria, Nuclear Fuel Cycle, Gram Positive Bacteria, Fresh water, Hydrogenase, Functional Group, Industrial Waste, Microbial Diversity, Natural Attenuation, Oxidation-Reduction, and Molecular Sequence Data
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Numerous studies have established a relationship between soil, sediment, surface biofilm and subsurface contaminant pollution and a marked impact on the in situ microbial community in both microcosms and in the field. The impact of... more
Numerous studies have established a relationship between soil, sediment, surface biofilm and subsurface contaminant pollution and a marked impact on the in situ microbial community in both microcosms and in the field. The impact of pollution on the in situ microbial ...
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Research Interests: Biological Sciences, Ecological Indicator, Environmental Sciences, Discriminant Analysis, Gram Positive, and 13 moreUnited States, Anthropogenic Disturbance, Recovery, Ecological Indicators, Cross Validation, Heavy Traffic, CHEMICAL SCIENCES, Gram-negative bacteria, Indexation, Community Composition, Artificial Neural Network, Microbial community, and Soil microbial biomass
Cesium, cadmium, cobalt, and strontium are four contaminants frequently found in soils at biotoxic levels. Introduction of certain nongenetically modified bacteria has been frequently suggested as a method for the immobilization of heavy... more
Cesium, cadmium, cobalt, and strontium are four contaminants frequently found in soils at biotoxic levels. Introduction of certain nongenetically modified bacteria has been frequently suggested as a method for the immobilization of heavy metal contaminants in soil, thereby reducing runoff and bioavailability. In this study, we have used the polymerase chain reaction (PCR) and denaturing gradient gel electrophoresis (DGGE) to track the survival of five bacterial species added to soil microcosms with and without the addition of a mixture of these metals. The PCR primers targeted conserved regions of the 16S rDNA molecule present in all bacteria. The reaction products were shown to reflect the relative abundance of the bacteria both in mixtures of pure cultures and against a background of all the eubacterial species present in the soil following inoculation. Three of the species (Pseudomonas aeruginosa FRD-1, Shewanella putrifaciens 200, and Desulfovibrio vulgaris Hildenborough) decreased rapidly following inoculation into both soils. The proportion of Alcaligenes eutrophus CH34 remained at a constant level throughout the 8-week experiment in both soil treatments. Sphingomonas aromaticivorans B0695 showed toxic metal-dependent survival in that its relative abundance dropped rapidly in pristine soil but remained at approximately inoculation levels throughout the experiment in contaminated microcosms.
Research Interests: Biological Sciences, Environmental Sciences, Polymerase Chain Reaction, Alkali Metals, Pseudomonas aeruginosa, and 8 moreCHEMICAL SCIENCES, Heavy Metal Contamination, Toxic Metals, Chemical Reaction, Pseudomonas Aeruginosa, Relative Abundance, Environmental Toxicology and Chemistry, and Environmental
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Research Interests: Microbiology, Geology, Medical Microbiology, Ecology, Mining, and 15 moreSequence Analysis, Phylogeny, Canadian, Uranium, Oxidoreductases, Population Size, Community Structure, New Mexico, Ammonia, Genetic variation, Veterinary Sciences, Water Microbiology, Betaproteobacteria, Ammonia oxidizing bacteria, and Nitrosomonas
Research Interests: Microbiology, Medical Microbiology, Sequence Analysis, Phylogeny, Polymerase Chain Reaction, and 15 morePhylogenetic analysis, Seawater, Species Composition, HYDROCARBONS, Crude Oil, Electrophoresis, Fresh water, Water Microbiology, Culture Media, DGGE, Geologic Sediments, Carbon Source, Full Length Movies, Proteobacteria, and Molecular Sequence Data
Research Interests: Microbiology, Medical Microbiology, Sequence Analysis, Phylogeny, Polymerase Chain Reaction, and 15 morePhylogenetic analysis, Seawater, Species Composition, HYDROCARBONS, Crude Oil, Electrophoresis, Fresh water, Water Microbiology, Culture Media, DGGE, Geologic Sediments, Carbon Source, Full Length Movies, Proteobacteria, and Molecular Sequence Data
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... DON SWIFT Old Dominion University Department of Oceans, Earth, and Atmospheric Sciences Norfolk, Virginia, USA SARAH MACNAUGHTON National Environment Technology Centre AEA Technology Environment Culham, Abingdon, UK ...
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Research Interests: Microbiology, Microbial Ecology, Medical Microbiology, Competition, Polymerase Chain Reaction, and 10 moreSodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis, ribosomal RNA, Gel electrophoresis, Sensitivity and Specificity, DGGE, Alcaligenes, Proteobacteria, DNA fragmentation, Thermal Gradient, and Molecular Sequence Data
... 1 ,; Yun-Juan Chang 1 ,; Sarah J. Macnaughton 1 ,; S. Leigh Whitaker 2 ,; Christopher L. Hicks 2 ,; Kam T. Leung ... Correspondence: David C. White ... managed by Lockheed Martin Energy Research Corporation for the US Department of... more
... 1 ,; Yun-Juan Chang 1 ,; Sarah J. Macnaughton 1 ,; S. Leigh Whitaker 2 ,; Christopher L. Hicks 2 ,; Kam T. Leung ... Correspondence: David C. White ... managed by Lockheed Martin Energy Research Corporation for the US Department of Energy under Contract DE-AC05-960R22464. ...
Research Interests: Biological Sciences, Environmental Sciences, Polymerase Chain Reaction, Alkali Metals, Pseudomonas aeruginosa, and 8 moreCHEMICAL SCIENCES, Heavy Metal Contamination, Toxic Metals, Chemical Reaction, Pseudomonas Aeruginosa, Relative Abundance, Environmental Toxicology and Chemistry, and Environmental
Research Interests: Microbiology, Biomass, Medical Microbiology, Environmental Monitoring, Lipids, and 13 moreFatty acids, Intact polar lipids, Bacteria, Field Experiment, Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis, Species Richness, Soil Microbiology, Fatty Acid, Correlation coefficient, Indexation, Species Specificity, Diversity Indices, and Microbial community
Physiological status of microbial mats of the Ebro Delta (Tarragona, Spain) based on the extraction of lipids considered ``signature lipid biomarkers'' (SLB) from the cell membranes and walls of microorganisms has been analyzed. Data from... more
Physiological status of microbial mats of the Ebro Delta (Tarragona, Spain) based on the extraction of lipids considered ``signature lipid biomarkers'' (SLB) from the cell membranes and walls of microorganisms has been analyzed. Data from a day–night cycle show significant differences in viable cells countings (PLFA cells counts) ranging from 1.5 × 1010 to 5.0 × 1010 cells g−1 of sediment. Minimum values were observed at 18:00 and 6:00, when physicochemical conditions change drastically. The diversity of the microbial community was assessed by GC/MS analysis of phospholipid fatty acids (PLFA). The ratio of PLFA, representative of Gram-negative bacteria, comprises 47.8% of the total PLFA of the microbial mat community. The remaining PLFA was representative of Gram-positive (10.0%), anaerobic (5.7%), and eukaryotic microorganisms (5.7%), and other common lipids. Two different approaches were used as a comparative study to assess the physiological status of the microbial mats. Two parameters (cyclopropane fatty acids/ω7c monoenoic fatty acids, and measurement of the trans/cis monoenoic PLFA ratio) showed a minimum at midnight, suggesting the highest microbial activity. Higher values were observed at 18:00 and 6:00, coinciding with lower PLFA cell counts.