Phillip Fedorak - Academia.edu (original) (raw)
Papers by Phillip Fedorak
Waste Management & Research, 1991
In planning for a new sanitary landfill site, the City of Edmonton, Canada considered the potenti... more In planning for a new sanitary landfill site, the City of Edmonton, Canada considered the potential for dissemination of micro-organisms via aerosols and by gulls that feed on the refuse . The health impacts on the residents and chicken and mushroom farming activities in the vicinity of the proposed location were assessed . Conclusions based on a review of information in the literature and in the City's planning documents were : (1) the densities of airborne microbes generated at the landfill site would be less than those observed at sewage treatment plants which cause very little health risk ; (2) chicken and mushroom farming operations generate very high densities of airborne microbes and the small numbers of microbes that might originate from the landfill site would be insignificant ; (3) the proximity of the proposed landfill location to an existing landfill site would not likely change the number of gulls in the area ; (4) sound agricultural practices (such as preventing wild birds from contacting poultry, or their water supplies, food and new litter) will minimize risk of the spread of pathogens to chickens from gulls .
Journal of Aoac International, 2002
Sulfolane and alkanolamines are used extensively in the processing of sour natural gases. Over ma... more Sulfolane and alkanolamines are used extensively in the processing of sour natural gases. Over many years of operation, there have been inadvertent leaks of these chemicals to groundwater and wetlands surrounding gas processing facilities, leading to uptake by vegetation. Because sulfolane and alkanolamines are extremely water-soluble, their analysis has presented challenges, particularly requirements for suitable extraction from biological matrixes and soil, along with sensitive detection using commonly available instrumentation. Analytical methods usually use gas chromatography or liquid chromatography with a variety of detector systems. Sample preparation techniques may include extraction with organic solvents, water, or a combination of these. In some cases, direct aqueous injections have been used. Derivatization of alkanolamines has been used to improve the chromatographic separations and detection. More recent procedures, using positive-ion electrospray ionization mass spectrometry (MS), have been useful for the confirmation of uptake of the alkanolamines and transformation products by wetland vegetation. Future developments will likely center on further MS analyses for identification of metabolites and transformation products in aquatic environments.
Applied and Environmental Microbiology, Feb 1, 1994
Lignin peroxidase from Phanerochaete chrysosporium was used to study the oxidation of aromatic co... more Lignin peroxidase from Phanerochaete chrysosporium was used to study the oxidation of aromatic compounds, including polycyclic aromatic hydrocarbons and heterocyclic compounds, that are models of moieties of asphaltene molecules. The oxidations were done in systems containing water-miscible organic solvents, including methanol, isopropanol, N,N-dimethylformamide, acetonitrile, and tetrahydrofuran. Of the 20 aromatic compounds tested, 9 were oxidized by lignin peroxidase in the presence of hydrogen peroxide. These included anthracene, 1-, 2-, and 9-methylanthracenes, acenaphthene, fluoranthene, pyrene, carbazole, and dibenzothiophene. Of the compounds studied, lignin peroxidase was able to oxidize those with ionization potentials of <8 eV (measured by electron impact). The reaction products contain hydroxyl and keto groups. In one case, carbon-carbon bond cleavage, yielding anthraquinone from 9-methylanthracene, was detected. Kinetic constants and stability characteristics of lignin peroxidase were determined by using pyrene as the substrate in systems containing different amounts of organic solvent. Benzyl alkylation of lignin peroxidase improved its activity in a system containing water-miscible organic solvent but did not increase its resistance to inactivation at high solvent concentrations.
Ozone Sci Eng, 2009
It has been demonstrated in many advanced European drinking water facilities that the application... more It has been demonstrated in many advanced European drinking water facilities that the application of ozone in conjunction with a subsequent granular activated carbon (GAC) treatment step results in reduced distribution system disinfectant demand. This is due, in large measure, to the removal of biodegradable organic substances by miroorganisms colonizing the activated carbon. The concentration of easily biodegradable or assimilable caron (AOC) can be measured in various ways. This paper compares available methods for measuring AOC or bacterial regrowth, and presents pilot plant results showing some factors affecting the van der Kooij method. Difficulties with the survival of Pseudomonas aeruginosa P17 strain following sedimentation are attributed to the use of polyaluminum chloride as a coagulant. This effect was, however, not evident at low doses of polyaluminum chloride. Incidents of inhibition of P17 following ozonation have been observed but, as of yet, not explained. Filtration of samples through cellulose/acetate filters will increase the concentration of AOC determined significantly.
Science of the Total Environment, Feb 1, 2009
Naphthenic acids, with the general formula C(n)H(2n+Z)O(2), are found in conventional petroleums ... more Naphthenic acids, with the general formula C(n)H(2n+Z)O(2), are found in conventional petroleums and oil sands ores. These acids are toxic to aquatic life, so their discharge from petroleum processing into receiving waters must be avoided. In a previous study, naphthenic acids were putatively identified in groundwaters from two domestic wells that were distant from petroleum sources. However, coal deposits were near these wells. In this study, waters from the two wells were extracted and analyzed by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry to unequivocally confirm the presence of naphthenic acids and other organic acids. In addition, distilled water was percolated through three crushed coal samples and the leachates were shown to contain a variety of organic acids, including naphthenic acids. These results clearly demonstrate that coal is a source of naphthenic acids and that the naphthenic acids can leach into groundwaters. Thus, the presence of naphthenic acids in waters cannot be solely attributed to petroleum or petroleum industry activities.
Applied and Environmental Microbiology, Feb 1, 1986
Isolates of Paecilomyces, Verticillium, Beauveria, and Penicilium species were tested for ability... more Isolates of Paecilomyces, Verticillium, Beauveria, and Penicilium species were tested for ability to metabolize a variety of n-alkylbenzenes. Minimum side chain lengths were required for metabolism of these substrates. These were C4 for the Paecilomyces sp., C8 for the Verticillium sp., and Cg for the other two isolates. Growth on dodecylbenzene yielded benzoic and phenylacetic acids as transient intermediates, and these acids supported growth of the isolates.
Journal of Industrial Microbiology and Biotechnology, Dec 1, 2002
Nitrate addition to oil field waters stops the biogenic formation of sulfide because the activiti... more Nitrate addition to oil field waters stops the biogenic formation of sulfide because the activities of nitrate -reducing bacteria ( NRB ) suppress the activities of sulfate -reducing bacteria ( SRB ). In general, there are two types of NRBthe heterotrophic NRB and the chemolithotrophic NRB. Within the latter group are the nitrate -reducing, sulfideoxidizing bacteria ( NR -SOB ). To date, no study has specifically addressed the roles of these different NRB in controlling sulfide concentrations in oil field produced waters. This study used different culture media to selectively enumerate heterotrophic NRB and NR -SOB by most probable number ( MPN ) methods. Produced waters from three sulfide -containing western Canadian oil fields were amended with nitrate as an electron acceptor, but no exogenous electron donor was added to the serum bottle microcosms. Changes in the chemical and microbiological characteristics of the produced waters were monitored during incubation at 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8C.
Applied and Environmental Microbiology, Dec 1, 1990
The distribution of genes for [Fe], [NiFe], and [NiFeSe] hydrogenases was determined for 22 Desul... more The distribution of genes for [Fe], [NiFe], and [NiFeSe] hydrogenases was determined for 22 Desulfovibrio species. The genes for [NiFe] hydrogenase were present in all species, whereas those for the [Fe] and [NiFeSe] hydrogenases had a more limited distribution. Sulfate-reducing bacteria from 16S rRNA groups other than the genus Desulfovibrio (R. Devereux, M. Delaney, F. Widdel, and D. A. Stahl, J. Bacteriol. 171:6689-6695, 1989) did not react with the [NiFe] hydrogenase gene probe, which could be used to identify different Desulfovibrio species in oil field samples following growth on lactate-sulfate medium.
Applied and Environmental Microbiology, 1997
Applied Microbiology and Biotechnology, May 31, 1996
... process (Silverman and Ehrlich 1964). In the presence of the bacteria at acidic pH,Fe > ox... more ... process (Silverman and Ehrlich 1964). In the presence of the bacteria at acidic pH,Fe > oxidation of the sulphide is the rate-limiting step (Silverman 1967) and therefore Fe > ions accumu-late in the system. In bioleaching, the ferric ...
Applied and Environmental Microbiology, Nov 1, 1991
A novel method for the identification of bacteria in environmental samples by DNA hybridization i... more A novel method for the identification of bacteria in environmental samples by DNA hybridization is presented. It is based on the fact that, even within a genus, the genomes of different bacteria may have little overall sequence homology. This allows the use of the labeled genomic DNA of a given bacterium (referred to as a "standard") to probe for its presence and that of bacteria with highly homologous genomes in total DNA obtained from an environmental sample. Alternatively, total DNA extracted from the sample can be labeled and used to probe filters on which denatured chromosomal DNA from relevant bacterial standards has been spotted. The latter technique is referred to as reverse sample genome probing, since it is the reverse of the usual practice of deriving probes from reference bacteria for analyzing a DNA sample. Reverse sample genome probing allows identification of bacteria in a sample in a single step once a master filter with suitable standards has been developed. Application of reverse sample genome probing to the identification of sulfate-reducing bacteria in 31 samples obtained primarily from oil fields in the province of Alberta has indicated that there are at least 20 genotypically different sulfate-reducing bacteria in these samples.
Preprints American Chemical Society Division of Petroleum Chemistry, 2003
Applied and Environmental Microbiology, 1998
Naphthothiophenes are minor components of fossil fuels, and they can enter the environment from o... more Naphthothiophenes are minor components of fossil fuels, and they can enter the environment from oil spills. Naphtho[2,1-b]thiophene, naphtho[2,3-b]thiophene, and 1-methylnaphtho[2,1-b]thiophene were synthesized and used in biodegradation studies with 1-methylnaphthalene (1-MN)-degrading Pseudomonas strains W1, F, and BT1. Cultures were incubated with one of the naphthothiophenes with or without 1-MN, acidified, and extracted with CH 2 Cl 2 . The extracts were analyzed by gas chromatography with flame photometric and mass detectors to characterize sulfur-containing metabolites and with an atomic emission detector for quantification. Only strain W1 was able to grow on naphtho[2,1-b]thiophene, but strains F and BT1 cometabolized this compound if 1-MN was present. 1-MN was required by all three strains to metabolize naphtho[2,3-b]thiophene, which was more resistant to biodegradation than the [2,1-b] isomer. Two metabolites of naphtho [2,1-b]thiophene were purified, analyzed by 1 H nuclear magnetic resonance spectroscopy, and found to be 4-hydroxybenzothiophene-5-carboxylic acid (metabolite I) and 5-hydroxybenzothiophene-4-carboxylic acid (metabolite II). In cultures of strain W1 grown for 7 days on 52 mol of naphtho[2,1-b]thiophene, >84% of the substrate was degraded and metabolites I and II accounted for 19 and 9%, respectively, of the original amount of naphtho[2,1-b]thiophene. When 1-MN was present, strain W1 degraded >97% of the naphtho[2,1-b]thiophene and similar amounts of metabolite II were produced, but metabolite I did not accumulate. 1-MN was shown to promote the further degradation of metabolite I, but not of metabolite II, by strain W1. Thus, 1-MN enhanced the biodegradation of naphtho[2,1-b]thiophene. Approximately 70% of the 1-methylnaphtho [2,1-b]thiophene added to cultures of strain W1 with 1-MN was recovered as 4-hydroxy-3-methylbenzothiophene-5-carboxylic acid, the 3-methyl analog of metabolite I. The methyl substitution hindered further metabolism of 3-methyl-metabolite I even in the presence of 1-MN. Cometabolism of naphtho[2,3-b]thiophene yielded two products that were tentatively identified as 5-hydroxybenzothiophene-6-carboxylic and 6-hydroxybenzothiophene-5-carboxylic acids.
Preprints American Chemical Society Division of Petroleum Chemistry, 2003
Preprints American Chemical Society Division of Petroleum Chemistry, 2003
Canadian Journal of Microbiology, Feb 10, 2011
A most probable number (MPN) method was used to enumerate dissimilatory ammonium-producing, nitra... more A most probable number (MPN) method was used to enumerate dissimilatory ammonium-producing, nitrate-reducing bacteria (DAP-NRB) in oil field waters and to determine whether they were stimulated by nitrate addition used to control hydrogen sulfide production. An ammonium production medium with 5 carbon and energy sources (acetate, glucose, glycerol, pyruvate, and succinate) and nitrate was used in a 3-tube MPN procedure to enumerate DAP-NRB. These bacteria were detected in 12 of 18 oil field water samples, but they were seldom detected in wellhead samples. Three oil field water samples were amended with nitrate in serum bottles and the numbers of different NRB were determined over a 38-day incubation time. This amendment stimulated increases in the numbers of heterotrophic NRB and autotrophic nitrate-reducing, sulfide-oxidizing bacteria, but DAP-NRB remained a minor portion of these communities. Overall, DAP-NRB were present in many of the oil field waters that were examined but their numbers were low. It appears that DAP-NRB would play a minor role in the consumption of nitrate injected into oil field waters for the control of hydrogen sulfide production.
Applied and Environmental Microbiology, Feb 1, 1990
The metabolism of m-cresol by methanogenic cultures enriched from domestic sewage sludge was inve... more The metabolism of m-cresol by methanogenic cultures enriched from domestic sewage sludge was investigated. In the initial studies, bromoethanesulfonic acid was used to inhibit methane production. This led to the accumulation of 4.0 ± 0.8 mol of acetate per mol of m-cresol metabolized. These results suggested that CO2 incorporation occurred because each molecule of m-cresol contained seven carbon atoms, whereas four molecules of acetate product contained a total of eight carbon atoms. To verify this, ['4C]bicarbonate was added to bromoethanesulfonic acid-inhibited cultures, and those cultures yielded [14C]acetate. Of the label recovered as acetate, 89% was found in the carboxyl position. Similar cultures fed [methyl-'4C]m-cresol yielded methyl-labeled acetate. A 14C-labeled transient intermediate was detected in cultures given either m-cresol and [14C]bicarbonate or bicarbonate and [methyl-14C]m-cresol. The intermediate was identified as 4-hydroxy-
Http Dx Doi Org 10 1080 09593339109385034, Dec 17, 2008
Waste Management & Research, 1991
In planning for a new sanitary landfill site, the City of Edmonton, Canada considered the potenti... more In planning for a new sanitary landfill site, the City of Edmonton, Canada considered the potential for dissemination of micro-organisms via aerosols and by gulls that feed on the refuse . The health impacts on the residents and chicken and mushroom farming activities in the vicinity of the proposed location were assessed . Conclusions based on a review of information in the literature and in the City's planning documents were : (1) the densities of airborne microbes generated at the landfill site would be less than those observed at sewage treatment plants which cause very little health risk ; (2) chicken and mushroom farming operations generate very high densities of airborne microbes and the small numbers of microbes that might originate from the landfill site would be insignificant ; (3) the proximity of the proposed landfill location to an existing landfill site would not likely change the number of gulls in the area ; (4) sound agricultural practices (such as preventing wild birds from contacting poultry, or their water supplies, food and new litter) will minimize risk of the spread of pathogens to chickens from gulls .
Journal of Aoac International, 2002
Sulfolane and alkanolamines are used extensively in the processing of sour natural gases. Over ma... more Sulfolane and alkanolamines are used extensively in the processing of sour natural gases. Over many years of operation, there have been inadvertent leaks of these chemicals to groundwater and wetlands surrounding gas processing facilities, leading to uptake by vegetation. Because sulfolane and alkanolamines are extremely water-soluble, their analysis has presented challenges, particularly requirements for suitable extraction from biological matrixes and soil, along with sensitive detection using commonly available instrumentation. Analytical methods usually use gas chromatography or liquid chromatography with a variety of detector systems. Sample preparation techniques may include extraction with organic solvents, water, or a combination of these. In some cases, direct aqueous injections have been used. Derivatization of alkanolamines has been used to improve the chromatographic separations and detection. More recent procedures, using positive-ion electrospray ionization mass spectrometry (MS), have been useful for the confirmation of uptake of the alkanolamines and transformation products by wetland vegetation. Future developments will likely center on further MS analyses for identification of metabolites and transformation products in aquatic environments.
Applied and Environmental Microbiology, Feb 1, 1994
Lignin peroxidase from Phanerochaete chrysosporium was used to study the oxidation of aromatic co... more Lignin peroxidase from Phanerochaete chrysosporium was used to study the oxidation of aromatic compounds, including polycyclic aromatic hydrocarbons and heterocyclic compounds, that are models of moieties of asphaltene molecules. The oxidations were done in systems containing water-miscible organic solvents, including methanol, isopropanol, N,N-dimethylformamide, acetonitrile, and tetrahydrofuran. Of the 20 aromatic compounds tested, 9 were oxidized by lignin peroxidase in the presence of hydrogen peroxide. These included anthracene, 1-, 2-, and 9-methylanthracenes, acenaphthene, fluoranthene, pyrene, carbazole, and dibenzothiophene. Of the compounds studied, lignin peroxidase was able to oxidize those with ionization potentials of <8 eV (measured by electron impact). The reaction products contain hydroxyl and keto groups. In one case, carbon-carbon bond cleavage, yielding anthraquinone from 9-methylanthracene, was detected. Kinetic constants and stability characteristics of lignin peroxidase were determined by using pyrene as the substrate in systems containing different amounts of organic solvent. Benzyl alkylation of lignin peroxidase improved its activity in a system containing water-miscible organic solvent but did not increase its resistance to inactivation at high solvent concentrations.
Ozone Sci Eng, 2009
It has been demonstrated in many advanced European drinking water facilities that the application... more It has been demonstrated in many advanced European drinking water facilities that the application of ozone in conjunction with a subsequent granular activated carbon (GAC) treatment step results in reduced distribution system disinfectant demand. This is due, in large measure, to the removal of biodegradable organic substances by miroorganisms colonizing the activated carbon. The concentration of easily biodegradable or assimilable caron (AOC) can be measured in various ways. This paper compares available methods for measuring AOC or bacterial regrowth, and presents pilot plant results showing some factors affecting the van der Kooij method. Difficulties with the survival of Pseudomonas aeruginosa P17 strain following sedimentation are attributed to the use of polyaluminum chloride as a coagulant. This effect was, however, not evident at low doses of polyaluminum chloride. Incidents of inhibition of P17 following ozonation have been observed but, as of yet, not explained. Filtration of samples through cellulose/acetate filters will increase the concentration of AOC determined significantly.
Science of the Total Environment, Feb 1, 2009
Naphthenic acids, with the general formula C(n)H(2n+Z)O(2), are found in conventional petroleums ... more Naphthenic acids, with the general formula C(n)H(2n+Z)O(2), are found in conventional petroleums and oil sands ores. These acids are toxic to aquatic life, so their discharge from petroleum processing into receiving waters must be avoided. In a previous study, naphthenic acids were putatively identified in groundwaters from two domestic wells that were distant from petroleum sources. However, coal deposits were near these wells. In this study, waters from the two wells were extracted and analyzed by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry to unequivocally confirm the presence of naphthenic acids and other organic acids. In addition, distilled water was percolated through three crushed coal samples and the leachates were shown to contain a variety of organic acids, including naphthenic acids. These results clearly demonstrate that coal is a source of naphthenic acids and that the naphthenic acids can leach into groundwaters. Thus, the presence of naphthenic acids in waters cannot be solely attributed to petroleum or petroleum industry activities.
Applied and Environmental Microbiology, Feb 1, 1986
Isolates of Paecilomyces, Verticillium, Beauveria, and Penicilium species were tested for ability... more Isolates of Paecilomyces, Verticillium, Beauveria, and Penicilium species were tested for ability to metabolize a variety of n-alkylbenzenes. Minimum side chain lengths were required for metabolism of these substrates. These were C4 for the Paecilomyces sp., C8 for the Verticillium sp., and Cg for the other two isolates. Growth on dodecylbenzene yielded benzoic and phenylacetic acids as transient intermediates, and these acids supported growth of the isolates.
Journal of Industrial Microbiology and Biotechnology, Dec 1, 2002
Nitrate addition to oil field waters stops the biogenic formation of sulfide because the activiti... more Nitrate addition to oil field waters stops the biogenic formation of sulfide because the activities of nitrate -reducing bacteria ( NRB ) suppress the activities of sulfate -reducing bacteria ( SRB ). In general, there are two types of NRBthe heterotrophic NRB and the chemolithotrophic NRB. Within the latter group are the nitrate -reducing, sulfideoxidizing bacteria ( NR -SOB ). To date, no study has specifically addressed the roles of these different NRB in controlling sulfide concentrations in oil field produced waters. This study used different culture media to selectively enumerate heterotrophic NRB and NR -SOB by most probable number ( MPN ) methods. Produced waters from three sulfide -containing western Canadian oil fields were amended with nitrate as an electron acceptor, but no exogenous electron donor was added to the serum bottle microcosms. Changes in the chemical and microbiological characteristics of the produced waters were monitored during incubation at 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8C.
Applied and Environmental Microbiology, Dec 1, 1990
The distribution of genes for [Fe], [NiFe], and [NiFeSe] hydrogenases was determined for 22 Desul... more The distribution of genes for [Fe], [NiFe], and [NiFeSe] hydrogenases was determined for 22 Desulfovibrio species. The genes for [NiFe] hydrogenase were present in all species, whereas those for the [Fe] and [NiFeSe] hydrogenases had a more limited distribution. Sulfate-reducing bacteria from 16S rRNA groups other than the genus Desulfovibrio (R. Devereux, M. Delaney, F. Widdel, and D. A. Stahl, J. Bacteriol. 171:6689-6695, 1989) did not react with the [NiFe] hydrogenase gene probe, which could be used to identify different Desulfovibrio species in oil field samples following growth on lactate-sulfate medium.
Applied and Environmental Microbiology, 1997
Applied Microbiology and Biotechnology, May 31, 1996
... process (Silverman and Ehrlich 1964). In the presence of the bacteria at acidic pH,Fe > ox... more ... process (Silverman and Ehrlich 1964). In the presence of the bacteria at acidic pH,Fe > oxidation of the sulphide is the rate-limiting step (Silverman 1967) and therefore Fe > ions accumu-late in the system. In bioleaching, the ferric ...
Applied and Environmental Microbiology, Nov 1, 1991
A novel method for the identification of bacteria in environmental samples by DNA hybridization i... more A novel method for the identification of bacteria in environmental samples by DNA hybridization is presented. It is based on the fact that, even within a genus, the genomes of different bacteria may have little overall sequence homology. This allows the use of the labeled genomic DNA of a given bacterium (referred to as a "standard") to probe for its presence and that of bacteria with highly homologous genomes in total DNA obtained from an environmental sample. Alternatively, total DNA extracted from the sample can be labeled and used to probe filters on which denatured chromosomal DNA from relevant bacterial standards has been spotted. The latter technique is referred to as reverse sample genome probing, since it is the reverse of the usual practice of deriving probes from reference bacteria for analyzing a DNA sample. Reverse sample genome probing allows identification of bacteria in a sample in a single step once a master filter with suitable standards has been developed. Application of reverse sample genome probing to the identification of sulfate-reducing bacteria in 31 samples obtained primarily from oil fields in the province of Alberta has indicated that there are at least 20 genotypically different sulfate-reducing bacteria in these samples.
Preprints American Chemical Society Division of Petroleum Chemistry, 2003
Applied and Environmental Microbiology, 1998
Naphthothiophenes are minor components of fossil fuels, and they can enter the environment from o... more Naphthothiophenes are minor components of fossil fuels, and they can enter the environment from oil spills. Naphtho[2,1-b]thiophene, naphtho[2,3-b]thiophene, and 1-methylnaphtho[2,1-b]thiophene were synthesized and used in biodegradation studies with 1-methylnaphthalene (1-MN)-degrading Pseudomonas strains W1, F, and BT1. Cultures were incubated with one of the naphthothiophenes with or without 1-MN, acidified, and extracted with CH 2 Cl 2 . The extracts were analyzed by gas chromatography with flame photometric and mass detectors to characterize sulfur-containing metabolites and with an atomic emission detector for quantification. Only strain W1 was able to grow on naphtho[2,1-b]thiophene, but strains F and BT1 cometabolized this compound if 1-MN was present. 1-MN was required by all three strains to metabolize naphtho[2,3-b]thiophene, which was more resistant to biodegradation than the [2,1-b] isomer. Two metabolites of naphtho [2,1-b]thiophene were purified, analyzed by 1 H nuclear magnetic resonance spectroscopy, and found to be 4-hydroxybenzothiophene-5-carboxylic acid (metabolite I) and 5-hydroxybenzothiophene-4-carboxylic acid (metabolite II). In cultures of strain W1 grown for 7 days on 52 mol of naphtho[2,1-b]thiophene, >84% of the substrate was degraded and metabolites I and II accounted for 19 and 9%, respectively, of the original amount of naphtho[2,1-b]thiophene. When 1-MN was present, strain W1 degraded >97% of the naphtho[2,1-b]thiophene and similar amounts of metabolite II were produced, but metabolite I did not accumulate. 1-MN was shown to promote the further degradation of metabolite I, but not of metabolite II, by strain W1. Thus, 1-MN enhanced the biodegradation of naphtho[2,1-b]thiophene. Approximately 70% of the 1-methylnaphtho [2,1-b]thiophene added to cultures of strain W1 with 1-MN was recovered as 4-hydroxy-3-methylbenzothiophene-5-carboxylic acid, the 3-methyl analog of metabolite I. The methyl substitution hindered further metabolism of 3-methyl-metabolite I even in the presence of 1-MN. Cometabolism of naphtho[2,3-b]thiophene yielded two products that were tentatively identified as 5-hydroxybenzothiophene-6-carboxylic and 6-hydroxybenzothiophene-5-carboxylic acids.
Preprints American Chemical Society Division of Petroleum Chemistry, 2003
Preprints American Chemical Society Division of Petroleum Chemistry, 2003
Canadian Journal of Microbiology, Feb 10, 2011
A most probable number (MPN) method was used to enumerate dissimilatory ammonium-producing, nitra... more A most probable number (MPN) method was used to enumerate dissimilatory ammonium-producing, nitrate-reducing bacteria (DAP-NRB) in oil field waters and to determine whether they were stimulated by nitrate addition used to control hydrogen sulfide production. An ammonium production medium with 5 carbon and energy sources (acetate, glucose, glycerol, pyruvate, and succinate) and nitrate was used in a 3-tube MPN procedure to enumerate DAP-NRB. These bacteria were detected in 12 of 18 oil field water samples, but they were seldom detected in wellhead samples. Three oil field water samples were amended with nitrate in serum bottles and the numbers of different NRB were determined over a 38-day incubation time. This amendment stimulated increases in the numbers of heterotrophic NRB and autotrophic nitrate-reducing, sulfide-oxidizing bacteria, but DAP-NRB remained a minor portion of these communities. Overall, DAP-NRB were present in many of the oil field waters that were examined but their numbers were low. It appears that DAP-NRB would play a minor role in the consumption of nitrate injected into oil field waters for the control of hydrogen sulfide production.
Applied and Environmental Microbiology, Feb 1, 1990
The metabolism of m-cresol by methanogenic cultures enriched from domestic sewage sludge was inve... more The metabolism of m-cresol by methanogenic cultures enriched from domestic sewage sludge was investigated. In the initial studies, bromoethanesulfonic acid was used to inhibit methane production. This led to the accumulation of 4.0 ± 0.8 mol of acetate per mol of m-cresol metabolized. These results suggested that CO2 incorporation occurred because each molecule of m-cresol contained seven carbon atoms, whereas four molecules of acetate product contained a total of eight carbon atoms. To verify this, ['4C]bicarbonate was added to bromoethanesulfonic acid-inhibited cultures, and those cultures yielded [14C]acetate. Of the label recovered as acetate, 89% was found in the carboxyl position. Similar cultures fed [methyl-'4C]m-cresol yielded methyl-labeled acetate. A 14C-labeled transient intermediate was detected in cultures given either m-cresol and [14C]bicarbonate or bicarbonate and [methyl-14C]m-cresol. The intermediate was identified as 4-hydroxy-
Http Dx Doi Org 10 1080 09593339109385034, Dec 17, 2008