Progress 01/15/09 to 01/14/14
Outputs
Target Audience: Target audiences reached during the duration of the project include: 1. undergraduate students in environmental sciences, microbiology, bioenvironmental engineering, environmental chemistry, biochemistry, biology. 2. graduate students in environmental sciences, microbiology, environmental engineering, environmental chemistry. 3. researchers in petroleum biodegradation, hydrocarbon contamination, applied microbiology, environmental engineering and clean-up. 4. readers of research journals related to biodegradation, environmental sciences, applied and environmental microbiology, environmental science and technology. 5. attendees of environmental sciences, applied environmental sciences scientific meetings where presentations were made. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? Craig Phelps consulted with us on the project as he was the one who first analyzed groundwater from the site being investigated. Amita Oka, graduate student carried out sampling, extractions, chemical analyses on GC-MS, DNA extractions, PCR analyses, QPCR analyses. Joseph Anello, Matthew Bruno, Shravan Dave, undergraduate research students assisted in all phases of the sampling, analyses and experiments. All three undergraduate students did a senior honors thesis in the lab. Gas Technology Institute, Chicago, Illinois, did some chemical analyses of the water samples. Three undergraduate honors research students learned chemical and molecular biology techniques, field sampling work, data analyses of results. Yanan Li, visiting graduate student carried out sampling, extractions, chemical analyses on GC-MS, DNA extractions, PCR analyses. Abigail Porter, postdoc, worked with Yanan Li and oversaw most of the work. Winifred Awa, Ashley Jennings, Nilar Win, David Ozga, Kyle Oschell, undergraduate research students assisted in all phases of the sampling, analyses and experiments. Two of the undergraduate students did a senior honors thesis in the lab. All undergraduate research students learned chemical and molecular biology techniques, field sampling work, data analyses of results. Nilar Win, Wei Jie Tan, undergraduate research students assisted in all phases of the sampling, analyses and experiments. These undergraduate students did a senior honors thesis in the lab. All undergraduate research students learned chemical and molecular biology techniques, field sampling work, data analyses of results. Sarah Wolfson, graduate student, did the bamA studies in the marine environment as a participant in the Microbial Ecology summer course at the Marine Biological Laboratory in Woods Hole, MA. This was a training opportunity for her in field work, field sampling and analyses of field data. Wie Jie Tan graduated May, 2013, was a biotechnology major and completed an undergraduate honors thesis on bamA gene diversity. Wie Jie presented his thesis defense in May, 2013. Daniel Hoffman is a junior and has been working on bamA diversity under different environmental conditions and is also working on an honors thesis. Sarah Wolfson is a graduate student who has been looking at hydrocarbon and PAH degradation in coastal marine environments. She has found bamA genes widely distributed in the marine environment. Dr. Porter has presented her work at national meetings and many times within the department and university. How have the results been disseminated to communities of interest? Dessimination is through peer reviewed publications, reports and presentations local, regional and national meetings, invited lectures and seminars. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
The natural microbial community has a well known capacity to clean our environment of unwanted, toxic, or hazardous chemicals. If it were not for the natural cleansing capabilities of the microbes in our aquatic, soil, and sediment habitats, our environmental would long ago have become uninhabitable. Our studies aim to understand in as much detail as possible the biological mechanisms that these complex microbial communities possess in the removal and biodegradation of unwanted organic chemicals. Petroleum is a natural product and microbes are able to degrade it both aerobically and anaerobically. The rates and extent of degradation, however, are limited by the molecular mass, solubility, accessibility, other limiting nutrients and environmental conditions such as temperature and pressure. Our investigations have shown that the anaerobic biodegradation of petroleum components can occur naturally in anoxic groundwaters in NJ. These processes are not rapid, but are specifically identifiable as taking place anaerobically through the identification of specific and unique metabolites of the degradation pathway. Furthermore, specific genes known to be responsible for anaerobic activation and degradation of petroleum components are also a key identification mechanism unique to anoxic habitats. In previous studies we demonstrated that at a NJ MGP contaminated ground water site, natural attenuation was demonstrated bu the presend of specific hydrocarbon metabolites produced by specific hydrocarbon degrading anaerobes. Since these compounds are unique and cannot be produced by other meants, it provides strong evidence for natural attenuation of the contamination taking place over time. The concentrations also decrease with distance from the source, further supporting the natural attenuation process. In this current project we were able to gain access to the same site 9 years later to examine changes in conditions over this time period. Furthermore, we now have biomolecular tools that can be used to detect and measure the specific genes that are responsible for the attack on the hydrocarbon molecule during its degradation under anaerobic conditions. By measuring the metabolic biomarker and also the genetic biomarker the site conditions can be comprehensively described. The observations show that both the biomolecular and the chemical metabolite data support each other give stronger support and further credence to natural attenuation taking place in the subsurface. These data support the ongoing discussion on using natural attenuation as a means of groundwater cleanup. Anaerobic aromatic degradation undergoes initial modification of the ring structure through various pathways. This includes the gasoline components BTEX and polycyclic aromatic hydrocarbons (PAH) such as naphthalene. Aside from the anaerobic conditions or community, the common intermediate prior to ring fission is benzoyl-CoA. We have been inviestigating the distribution and diversity of the ring opening hydrolase gene, bam A, for several years. We found wide distribution of bam A in a variety of environmental samples and that the sequence diversity from the different sites separated into 2 main clusters that did not appear to be related to site characteristics. The number of samples, however, need to be larger for stronger conclusions. The more information we gather on the anaerobic fate and degradation pathways of aromatic compounds the better we will understand the processes in the environment. This can help us assess conditions in the subsurface and the activity of anaerobic attenuation of contaminants.
Publications
- Type:
Other
Status:
Other
Year Published:
2009
Citation:
Invited speaker, Bioremediation Short Course, University of Helsinki, Department of Environmental Ecology and Toxicology, October 11-16, 2009.
- Type:
Other
Status:
Other
Year Published:
2009
Citation:
Invited Lecture, Biodegradation of petroleum compounds, Department of Civil and Environmental Engineering, University of Minnesota, Nov 20, 2009.
- Type:
Other
Status:
Other
Year Published:
2010
Citation:
Invited Lecture, Biodegradation, Georgia State University, Department of Microbiology, April 29, 2010.
- Type:
Other
Status:
Other
Year Published:
2010
Citation:
John M. Henske Endowed Lecture, Biodegradation of Oil, from the Exxon Valdez to the Deepwater Horizon, Yale University, Department of Environmental Engineering and Sciences. December 1, 2010.
- Type:
Other
Status:
Other
Year Published:
2012
Citation:
Invited Lecture, Petroleum Biodegradation, School of Environmental Engineering and Science, Tianjin University, Tianjin, China, January, 4 2012.
- Type:
Other
Status:
Other
Year Published:
2012
Citation:
American Chemical Society Special Symposium, "Hydrocarbon Degradation Without Benefit of Oxygen: Original Microbial Chemistry", March 25, 2012.
- Type:
Other
Status:
Other
Year Published:
2012
Citation:
Invited Lecture, Biodegradation of Petroleum, South China University of Technology, School of Environmental Engineering and Science, Guangzhou, China, November, 2012.
- Type:
Other
Status:
Other
Year Published:
2013
Citation:
Invited Lecture, Petroleum Hydrocarbon Biodegradation, Department of Applied Chemistry, University of Toronto, March, 2013.
- Type:
Other
Status:
Other
Year Published:
2014
Citation:
Invited Lecture, Institute of Soil Science, Guangzhou Academy of Sciences, Guangzhou, China, January 2014.
- Type:
Other
Status:
Other
Year Published:
2011
Citation:
Invited Lecture, Rutgers University Microbiology Symposium, Biodegradation of Oil, from the Exxon Valdez to the Deepwater Horizon, February, 2011.
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Progress 01/01/13 to 09/30/13
Outputs
Target Audience: Target audience include researchers and personnel in the fields of environmental sciences, microbiology, environmental consulting, water quality engineering, environmental engineering, ground water hydrology. In addition, state and federal environmental protection agencies are also target audiences. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? The project has provided opportunity for training of research scientists, graduate students, undergraduate student research projects and presentations at other institutions and professional scientific meetings. Dr. Abigail Porter is a research scientist who is lead author on several of the most recent publications. She has worked with and directly overseen the undergraduate research projects. Wie Jie Tan graduated May, 2013, was a biotechnology major and completed an undergraduate honors thesis on bamA gene diversity. Wie Jie presented his thesis defense in May, 2013. Daniel Hoffman is a junior and has been working on bamA diversity under different environmental conditions and is also working on an honors thesis. Sarah Wolfson is a graduate student who has been looking at hydrocarbon and PAH degradation in coastal marine environments. She has found bamA genes widely distributed in the marine environment. Dr. Porter has presented her work at national meetings and many times within the department and university. How have the results been disseminated to communities of interest? This is largely through the peer reviewed publications that are listed, and through the regional and national meetings. What do you plan to do during the next reporting period to accomplish the goals? More data will be collected on bamA gene diversity.
Impacts
What was accomplished under these goals?
Anaerobic aromatic degradation undergoes initial modification of the ring structure through various pathways. This includes the gasoline compenents, BTEX and polycyclic hydrocarbons such as naphthalene. Regardless of the anaerobic conditions or community responsible, the common intermediate prior to ring fission is benzoyl-CoA. We have been investigating the distribution and diversity of the ring opening hydrolase gene, bamA for the last several years. We found wide distribution of bamA in a variety of environmental samples and that the sequence diversity from the different sites separated into 2 clusters that did not appear to be related to site characteristics. The number of samples, however, are not broad enough or large enough for clear cut conclusions. Additional samples and analyses are needed and are being undertaken. The more information we gather on the anaerobic fate and degradation pathway of aromatic compounds, the better we will understand the processes in the environment. This can help us assess whether conditions in the subsurface that have been impacted with gasoline and other petroleum contaminants are improving. By monitoring pathway metabolites and specific genes related to key reactions, we can evaluate the bioremediation and natural attenuation processes in groundwater.
Publications
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2014
Citation:
PORTER, AW, LY YOUNG. 2014. The bamA gene for anaerobic ring fission is widely distributed in the environment. Frontiers in Microbiological Chemistry. (in press).
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2014
Citation:
HEENAN, J, AW PORTER, D NTARLAGIANNIS, LY YOUNG, DD WERKEMA, L SLATER. 2013. Sensitivity of the spectral induced polarization method to microbial enhanced oil recovery processes. Geophysics 78(5):E261-E269.
- Type:
Journal Articles
Status:
Published
Year Published:
2012
Citation:
LI, Y, AW PORTER, A MUMFORD X ZHAO & LY YOUNG. 2012. Bacterial community structure and bamA gene diversity in anaerobic degradation of toluene and benzoate under denitrifying conditions. J Appl Microbiol. 112:269-279.
- Type:
Journal Articles
Status:
Awaiting Publication
Year Published:
2014
Citation:
PORTER, AW, LY YOUNG. 2014. Benzoyl-CoA, a universal biomarker for anaerobic degradation of aromatic compounds. Advances in Applied Microbiology. (in press).
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Progress 01/01/12 to 12/31/12
Outputs
OUTPUTS: Freshwater samples were obtained from a eutrophic pond to examine the bamA gene diversity in the anaerobic degradation of toluene and benzoate under denitrifying conditions. The bamA gene is downstream from the initial reactions for aromatic hydrocarbons and encodes for benzoyl-CoA degradation. Nitrate-reducing enrichment cultures were established on either toluene, benzoate or without additional substrate. Bacterial community structures were characterized by 16S rRNA gene-based PCR-DGGE analysis. bamA gene diversity was analysed using DGGE and cloning methods. The results showed that bamA gene related to bamA gene of Thauera chlorobenzoica was dominant in toluene and benzoate cultures. However, a greater diversity of sequences was obtained in benzoate cultures. Low diversity of bamA gene was observed, and some similarities of bamA were also found between active cultures and backgrounds, suggesting that potential natural attenuation of aromatic compounds could occur. Effort also was focused on examining bamA gene diversity in marine sediments including Eel Pond (small boat harbor), Wild Harbor, and Sippewiwisset Marsh. bamA diversity in these marine sediments divided into 2 main clusters. The 2 cluster, however, could not be separated by any physical differences (ecosystem, sediment morphology, tidal distribution). Dissemination included a presentation made at national scientific meeting and invited seminars given at Rutgers and elsewhere. 1. Seminar given at Rutgers, bamA gene diversity in different habitats, 2. Seminars given at Tianjin University and South China University of Technology, China, Anaerobic biodegradation of oil from the Exxon Valdez to the Deepwater Horizon. PARTICIPANTS: L.Y. Young PI has overall responsibility for the project. Craig Phelps consulted with us on the project as he was the one who first analyzed groundwater from the site being investigated. Abigail Porter, postdoc, worked with both undergraduate research students and oversaw most of the work. Nilar Win, Wei Jie Tan, undergraduate research students assisted in all phases of the sampling, analyses and experiments. These undergraduate students did a senior honors thesis in the lab. All undergraduate research students learned chemical and molecular biology techniques, field sampling work, data analyses of results. Sarah Wolfson, graduate student, did the bamA studies in the marine environment as a participant in the Microbial Ecology summer course at the Marine Biological Laboratory in Woods Hole, MA. This was a training opportunity for her in field work, field sampling and analyses of field data. TARGET AUDIENCES: Target audience include researchers and personnel in the fields of environmental sciences, microbiology, environmental consulting, water quality engineering, environmental engineering, ground water hydrology. In addition, state and federal environmental protection agencies, electric and gas utilities are also target audiences. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Underground or above ground fuel storage tanks can leak and contaminate groundwater used for irrigation or human consumption. This can end up as a costly clean-up even if the groundwater is not used as drinking water. Determining the rate and extent of the natural biodegradation of fuel components provides information on natural attenuation processes that can remove the contaminants. Chemical identification of signature metabolites can be used to identify any ongoing biodegradation process. Even more interesting is that we have the tools to determine the genetic signature that can identify the microbiological pathway of degradation. We are testing gene probes specific to the degradation pathway as an additional marker that unambiguous. We have extended the gene probing to other genes in the anaerobic degradation pathway during this phase of the study. These observations support the ongoing discussions on using natural attenuation as a means of groundwater or sediment contaminant cleanup.
Publications
- MUMFORD AC, JL BARRINGER, WM BENZEL, PA REILLY & LY YOUNG. 2012. Microbial transformations of arsenic: mobilization from glauconitic sediments to water. Water Res. 46:2859-2868.
- WANG Y, HA WIATROWSKI, R JOHN, CC LIN, LY YOUNG, LJ KERKHOF, N YEE, T BARKAY. 2012. Impact of mercury on denitrification and denitrifying microbial communities in nitrate enrichments of subsurface sediments. Biodegradation DOI 10.1007/s10532-012-9555-8.
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Progress 01/01/11 to 12/31/11
Outputs
OUTPUTS: Samples from the Deepwater Horizon oil spill in the Gulf of Mexico were obtained to examine if there is anaerobic hydrocarbon biodegradation, and to determine if the dispersant used (Corexit) had an impact on the anaerobic biodegradation process. In addition, we obtained freshwater samples from a eutrophic pond to examine the bamA gene diversity in the anaerobic degradation of toluene and benzoate under denitrifying conditions. The bamA gene is downstream from the initial reactions for aromatic hydrocarbons and encodes for benzoyl-CoA degradation. Anaerobic toxicity assays showed that the Corexit had little effect on anaerobic biodegradation under a range of concentrations, including those several orders of magnitude higher than what was used in the Gulf of Mexico. Nitrate-reducing enrichment cultures were established on either toluene, benzoate or without additional substrate. Bacterial community structures were characterized by 16S rRNA gene-based PCR-DGGE analysis. bamA gene diversity was analysed using DGGE and cloning methods. The results showed that bamA gene related to bamA of Thauera chlorobenzoica was dominant in toluene and benzoate cultures. However, a greater diversity of sequences was obtained in benzoate cultures. Low diversity of bamA gene was observed, and some similarities of bamA were also found between active cultures and backgrounds, suggesting that potential natural attenuation of aromatic compounds could occur. Dissemination included a presentation made at national scientific meeting and invited seminars given at Rutgers and elsewhere. 1. Porter, A.W., Y. Li, M. Rivera, L. Kerkhof, and L.Y. Young. 2011. Anaerobic aromatic metabolism: benzoate gene diversity and implications for the Gulf oil spill. Gordon Research Conference on Applied & Environmental Microbiology, South Hadley, MA. 2. Seminar given at Rutgers, Biodegradation of oil, from the Exxon Valdez to the Deepwater Horizon 3. Seminar given at Yale, Anaerobic biodegradation of oil from the Exxon Valdez to the Deepwater Horizon. PARTICIPANTS: L.Y. Young PI has overall responsibility for the project. Craig Phelps consulted with us on the project as he was the one who first analyzed groundwater from the site being investigated. Yanan Li, visiting graduate student carried out sampling, extractions, chemical analyses on GC-MS, DNA extractions, PCR analyses. Abigail Porter, postdoc, worked with Yanan Li and oversaw most of the work. Winifred Awa, Ashley Jennings, Nilar Win, David Ozga, Kyle Oschell, undergraduate research students assisted in all phases of the sampling, analyses and experiments. Two of the undergraduate students did a senior honors thesis in the lab. All undergraduate research students learned chemical and molecular biology techniques, field sampling work, data analyses of results. TARGET AUDIENCES: Target audiences include researchers and personnel in the fields of environmental sciences, microbiology, environmental consulting, water quality engineering, environmental engineering, ground water hydrology. In addition, state and federal environmental protection agencies, electric and gas utilities are also target audiences. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Underground or above ground fuel storage tanks can leak and contaminate groundwater used for irrigation or human consumption. This can end up as a costly clean-up even if the groundwater is not used as drinking water. Determining the rate and extent of the natural biodegradation of fuel components provides information on natural attenuation processes that can remove the contaminants. Chemical identification of signature metabolites can be used to identify any ongoing biodegradation process. Even more interesting is that we have the tools to determine the genetic signature that can identify the microbiological pathway of degradation. We are testing gene probes specific to the degradation pathway as an additional marker that unambiguous. We have extended the gene probing to other genes in the anaerobic degradation pathway during this phase of the study. These observations support the ongoing discussions on using natural attenuation as a means of groundwater cleanup.
Publications
- OKA AR, CDPHELPS, X ZHU, DL SABER & LY YOUNG. 2011. Dual biomarkers of anaerobic hydrocarbon degradation in historically contaminated groundwater. Environ Sci Technol 45:3407-3414.
- LI, Y, AW PORTER, A MUMFORD X ZHAO & LY YOUNG. 2012. Bacterial community structure and bamA gene diversity in anaerobic degradation of toluene and benzoate under denitrifying conditions. J Appl Microbiol. In press.
- CALLAGHAN, AV, BEL MORRIS, IAC PEREIRA, MJ MCINERNEY, JJ KUKOR, JM SUFLITA, GJ ZYLSTRA, RN AUSTIN, JJ GROVES, LY YOUNG & B WAWRIK. 2011. The genome sequence of Desulfatibacillum alkenivorans AK-01: a blueprint for anaerobic alkane oxidation. Environ Microbiol. DOI:10.1111/j.1462-2920.2011.02516.x
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Progress 01/01/10 to 12/31/10
Outputs
OUTPUTS: The data from the field work described last year was the subject of analyses and examination during this year's effort. Here is a summary of the field work. Groundwater samples within and outside the plume of contaminants were collected to analyze for metabolic and genetic biomarkers of hydrocarbon biodegradation. Metabolic biomarkers included intermediates of anaerobic naphthalene and 2-methylnaphthalene degradation. The genetic biomarker was the gene bssA encoding for the alpha subunit of the enzyme benzylsuccinate synthase (Bss). Samples were analyzed by GC-MS and DNA extracts were used for end-point and quantitative PCR analysis. QPCR analysis of 16S rRNA genes in eubacteria indicated that abundance of total bacteria was 1-2 orders of magnitude higher within the impacted wells, as compared to the unimpacted wells. Using end-point PCR analysis, bssA genes were detected in the impacted wells, which indicate the presence of hydrocarbon degrading bacteria. Presence of bssA genes in the samples was confirmed by DNA sequence. High abundance of specific metabolic intermediates and bssA gene analogues within the plume indicate that the site was enriched for anaerobic hydrocarbon degradation. Analysis showed a distribution of both the metabolic and the molecular biomarkers were in high concentration near the contaminant source and decreased in concentration downgradient from the source. Molecular biomarkers are specific to the microbes that are responsible for the anaerobic biodegradation process. Data showed that their numbers and the gene copies for the anaerobic hydrocarbon genes are high near the source providing strong support for natural attenuation at the site. The work was extended to marine sediment samples. Dissemination included a presentation made at national scientific meeting and invited seminars given at Rutgers and elsewhere. 1. "Anaerobic Transformation of Carboxylic Acids in Guaymas Basin Enrichments", Goldschmidt Geochemistry Conference, June 13-17, 2010, Knoxville, TN. An abstract was published. 2. Seminar given at NYU, "Petroleum Hydrocarbons: Anaerobic Biodegradation in the Lab and in the Field." 3. Seminar given at Georgia State University, "Petroleum Hydrocarbons: Anaerobic Biodegradation in the Lab and in the Field." PARTICIPANTS: L.Y. Young PI has overall responsibility for the project. Craig Phelps consulted with us on the project as he was the one who first analyzed groundwater from the site being investigated. Amita Oka, graduate student carried out sampling, extractions, chemical analyses on GC-MS, DNA extractions, PCR analyses, QPCR analyses. Joseph Anello, Matthew Bruno, Shravan Dave, undergraduate research students assisted in all phases of the sampling, analyses and experiments. All three undergraduate students did a senior honors thesis in the lab. Gas Technology Institute, Chicago, Illinois, did some chemical analyses of the water samples. Three undergraduate honors research students learned chemical and molecular biology techniques, field sampling work, data analyses of results. TARGET AUDIENCES: Target audience include researchers and personnel in the fields of environmental sciences, microbiology, environmental consulting, water quality engineering, environmental engineering, ground water hydrology. In addition, state and federal environmental protection agencies, electric and gas utilities are also target audiences. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Underground or above ground fuel storage tanks can leak and contaminate groundwater used for irrigation or human consumption. This can end up as a costly clean-up even if the groundwater is not used as drinking water. Determining the rate and extent of the natural biodegradation of fuel components provides information on natural attenuation processes that can remove the contaminants. Chemical identification of signature metabolites can be used to identify any ongoing biodegradation process. Even more interesting is that we have the tools to determine the genetic signature that can identify the microbiological pathway of degradation. We are testing gene probes specific to the degradation pathway as an additional marker that unambiguous. These observations support the ongoing discussions on using natural attenuation as a means of groundwater cleanup.
Publications
- WALCZAK AB, N YEE & LY YOUNG. 2010. Bosea sp. WAO oxidizes metal sulfides at neutral pH. Abstract for the Goldschmidt Geochemistry Meeting, Knoxville, TN, June 2010.
- MUMFORD A, J BARRINGER P REILLY & LY YOUNG. 2010. Potential role for bacteria in arsenic release to groundwater. Abstract for the Goldschmidt Geochemistry Meeting, Knoxville, TN, June 2010.
- PORTER AW, C VETRIANI & LY YOUNG. 2010. Aromatic carboxylic acids are anaerobically transformed in Guaymas Basin Sediments. Abstract for the Goldschmidt Geochemistry Meeting, Knoxville, TN, June 2010.
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Progress 01/01/09 to 12/31/09
Outputs
OUTPUTS: Contaminated ground water samples were collected in the field and analyzed for metabolic and molecular biomarkers for anaerobic alkane and PAH degradation. Groundwater samples within and outside the plume of contaminants were collected to analyze for metabolic and genetic biomarkers of hydrocarbon biodegradation. Metabolic biomarkers included intermediates of anaerobic naphthalene and 2-methylnaphthalene degradation. The genetic biomarker was the gene bssA encoding for the alpha subunit of the enzyme benzylsuccinate synthase (Bss). Samples were analyzed by GC-MS and DNA extracts were used for end-point and quantitative PCR analysis. QPCR analysis of 16S rRNA genes in eubacteria indicated that abundance of total bacteria was 1-2 orders of magnitude higher within the impacted wells, as compared to the unimpacted wells. Using end-point PCR analysis, bssA genes were detected in the impacted wells, which indicate the presence of hydrocarbon degrading bacteria. Presence of bssA genes in the samples was confirmed by DNA sequence. High abundance of specific metabolic intermediates and bssA gene analogues within the plume indicate that the site was enriched for anaerobic hydrocarbon degradation. Analysis showed a distribution of both the metabolic and the molecular biomarkers were in high concentration near the contaminant source and decreased in concentration downgradient from the source. Molecular biomarkers are specific to the microbes that are responsible for the anaerobic biodegradation process. Data showed that their numbers and the gene copies for the anaerobic hydrocarbon genes are high near the source providing strong support for natural attenuation at the site. Dissemination included presentations made at national and international scientific meetings: 1. Metabolic biomarkers and biomolecular signatures provide evidence for natural attenuation of hydrocarbons in anoxic groundwater, Annual Meeting American Society of Microbiology, Philadelphia, May 17-21, 2009. An abstract was published. 2. Evidence for anaerobic biodegradation of hydrocarbons in the subsurface environment. Goldschmidt Symposium. Davos, Switzerland, June 21-26, 2009. An abstract was published. An intensive short course was given at the Department of Ecological and Environmental Sciences, at the University of Helsinki, Lahti, Finland, October 12-16, 2009. Lectures were given on hydrocarbon biodegradation fundamentals and field studies to advanced graduate students from northern Europe. PARTICIPANTS: L.Y. Young PI has overall responsibility for the project. Craig Phelps consulted with us on the project as he was the one who first analyzed groundwater from the site being investigated. Amita Oka, graduate student carried out sampling, extractions, chemical analyses on GC-MS, DNA extractions, PCR analyses, QPCR analyses. Joseph Anello, Matthew Bruno, Shravan Dave, undergraduate research students assisted in all phases of the sampling, analyses and experiments. All three undergraduate students did a senior honors thesis in the lab. Gas Technology Institute, Chicago, Illinois, did some chemical analyses of the water samples. Three undergraduate honors research students learned chemical and molecular biology techniques, field sampling work, data analyses of results. TARGET AUDIENCES: Target audience include researchers and personnel in the fields of environmental sciences, microbiology, environmental consulting, water quality engineering, environmental engineering, ground water hydrology. In addition, state and federal environmental protection agencies, electric and gas utilities are also target audiences. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
In previous studies we demonstrated that at this MGP (manufactured gas plant) contaminated ground water site in southern New Jersey natural attenuation could be demonstrated by the presence in the ground water of specific hydrocarbon metabolites produced by specific hydrocarbon degrading bacteria. Since these compounds are unusual and cannot be produced by other means, it provides strong support for natural attenuation of the contamination taking place over time. The concentrations also decrease with distance from the source, further supporting the natural attenuation process. In this current project, we were able to gain access to the same site 9 years later to examine changes in conditions over this time period. Furthermore, we now have biomolecular tools that can be used to detect and measure the specific genes that are responsible for the initial attack of the hydrocarbon molecule during its degradation under anaerobic conditions. By measure both the chemical metabolic biomarkers and also the genetic biomarkers, the site conditions could be comprehensively described. The observations showed that both the biomolecular and the chemical metabolite data support each other giving further credence to natural attenuation taking place in the groundwater. These data support the ongoing discussions on using natural attenuation as a means of groundwater cleanup.
Publications
- Callaghan AV, M Tierney, CD Phelps & LY Young. 2009. Anaerobic biodegradation of hexadecane by a nitrate-reducing consortium. Appl Environ Microbiol 75:1339-1334.
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