Progress 09/01/05 to 08/31/10
Outputs
OUTPUTS: Four students were supported by this National Needs Fellowship (NNF) program. Three successfully completed PhD degrees and one completed an MS degree and then continued on after the NNF program to a PhD. An African-American female diversity candidate failed to maintain adequate progress towards her PhD degree, in spite of interventions, and dropped out of the program. Three PhD dissertations and one MS thesis were submitted to The Ohio State University as partial fulfillment of degree requirements. Much of this work has been presented at scientific meetings and published as refereed research articles. N.N. Merrick and D.C. Florence extended their NNF experience by both becoming National Science Foundation (NSF) Graduate Science, Technology, Engineering and Math (STEM) Fellows in K-12 Education Program. They developed and presented science-based programs that came out of their NNF program experience to high schools located in the Sugar Creek watershed, Ohio. PARTICIPANTS: Three Ohio State University professors served as mentors to graduate students supported by this National Needs Fellowship program. Dr. Warren A. Dick and Dr. Richard P. Dick in soil science and Dr. Olli H. Tuovinen in microbiology worked with four graduate students to develop scientific and technical expertise in microbial soil ecology. This work was extended when two students, Darlene C. Florence and Natsuko N. Merrick, participated in a National Science Foundation (NSF) Graduate Science K-12 Education program in Science, Technology, Engineering and Math (STEM). This work was primarily focused within schools located within a small watershed in Ohio, i.e. the Sugar Creek watershed. However, the materials produced are appropriate for many schools seeking relevant STEM materials to teach in their classrooms. TARGET AUDIENCES: Graduate students, high school teachers, K-12 students all benefitted from this project. Four graduate students were supported in part or whole by this NNF program and three received PhD degrees and one received an MS degree. The student receiving an MS degree went on to complete her PhD degree in a related program. Female and minority candidates were recruited and three of the four graduate students were female. Of these three female students, one was Asian and one was of Middle East descent. An African American female student was recruited but was unable to complete the program because of academic problems, in spite of intervention efforts. Another target audience was the scientific community and a significant number of refereed publications and presentations (both national and international) were produced out of this project. This includes a patent that is pending on a rapid soil biochemical test to determine disease incidence of Phytophthora sojae in soybean fields. Elementary and high school students benefitted because two of the graduate students involved in this National Needs Fellowship program also became involved in a National Science Foundation program in Science, Technology, Engineering and Math (STEM) that targeted K-12 students. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
The purpose of the NNF program is to develop scientific and technical expertise in critical needs areas. This project was focused in the area of soil microbial ecology. The students that were supported by this program, after completing their degrees, have continued to be very professionally active. L.F. Yousef is currently an Assistant Professor, Water and Environmental Engineering, Masdar Institute, Abu Dhabi, United Arab Emirate with close ties to the Massachusetts Institute of Technology (MIT), Cambridge, MA. Dr. Florence, after completing her NNF program moved on to a PhD and worked in Africa. She is currently an adjunct faculty in the Soil Science, Agronomy and Engineering Technology Division, The Ohio State University - Agricultural Technical Institute, Wooster, OH. N.N. Merrick is currently serving as the program manager of an National Science Foundation GK-12 program that is located at the The Ohio State University / The Ohio Agricultural Research and Development Center, Wooster, Ohio. This program develops science-based programs for GK-12 classroom use.
Publications
- Florence, D.C. 2009. Growth performance of six plant species and removal of heavy metal pollutants (Cu, Cr. Pb and Zn) in a field-scale bi-phasic rain garden. M.S. Thesis. The Ohio State University, Columbus, OH.
- Yousef, L.F. 2010. Class-I elicitins in relation to sterol acquisition and lipid profiling of Phytophthora sojae. Ph.D. Dissertation, The Ohio State University, Columbus, OH.
- Merrick, N.N. 2010. Microbial source tracking: Watershed scale study of pathogen origin, fate, and transport in the upper Sugar Creek watershed, Northeast Ohio. Ph.D. Dissertation, The Ohio State University, Columbus, OH.
- Carver, S.M. 2011. Characterization of a thermophilic, cellulolytic microbial culture. Ph.D. Dissertation, The Ohio State University, Columbus, OH.
- Yang H.B, Florence, D.C., McCoy, E.L. Dick, W.A., and Grewal, P.S. 2009. Design and hydraulic characteristics of a field-scale bi-phasic bioretention rain garden system for stormwater management. Water, Science & Technology. 59:1863-72.
- Yousef, L.F, Yousef A.F., Mymryk J.S., Dick,W.A., and Richard, R.P. 2009. Stigmasterol and cholesterol regulate the expression of elicitin genes in Phytophthora sojae. Journal of Chemical Ecology 35:824-832.
- Yousef, L.F, Dick, W.A., and Dick R.P. 2011. Use of a 15N-tracer method as a tool to indicate the assimilation of elicitin-sterol complexes by Phytophthora sojae. International Journal of Biology 3:119-127.
- Carver, S.M., Vuoriranta, P., and Tuovinen, O.H. 2011. A thermophilic microbial fuel cell design. Journal of Power Sources 196:3757-3760.
- Carver, S.M., Nelson, M.C., Yu, Z., and Tuovinen, O.H. 2012. Hydrogen and volatile fatty acid production during fermentation of cellulosic substrates by a thermophilic consortium at 50 and 60 C. Bioresource Technology 104:424-431.
- Rismani-Yazdi, H., Carver, S.M., Christy, A.D., Yu, Z., Bibby, K., Peccia, J., and Tuovinen, O.H. 2013. Suppression of methanogenesis in cellulose-fed microbial fuel cells in relation to performance, metabolite formation, and microbial population. Bioresource Technology, in press (http://dx.doi.org/10.1016/j.biortech.2012.10.137).
- Drozd, M., Merrick, N., Sanad, Y.M., Dick, L., Dick, W.A., and Rajashekara, G. 2013. Evaluating the occurrence of host-specific Bacteroidales, general fecal indicators and bacterial pathogens in a mixed use watershed. Journal of Environmental Quality (accepted).
- Carver, S.M., Lepisto, R., and Tuovinen, O.H. 2010. Hydrolysis and metabolism of cellulose by an anaerobic, thermophilic consortium. In: Proceedings of the Third Conference on Energy from Biomass and Waste. CISA-Environmental Sanitary Engineering Centre, Padova, Italy, Paper 436, 9 p.
- Yousef, L.F., Dick, W.A., and Dick, R.P. 2012. A rapid soil biochemical test to determine disease incidence of Phytophthora sojae in soybean fields. Patent pending. Tech ID #10110F, The Ohio State University.
- Carver, S.M., Hulatt, C.J., Thomas, D.N., and Tuovinen, O.H. 2011. Thermophilic, anaerobic co-digestion of microalgal biomass and cellulose for H2 production. Biodegradation 22:805-814.
- Yousef, L.F., Wojno M., Dick, W.A., and Dick, R.P. 2012. Lipid profiling of the soybean pathogen Phytophthora sojae using fatty acid methyl esters (FAME). Fungal Biology 116:613-619.
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Progress 09/01/06 to 08/31/07
Outputs
This project is currently supporting two soil microbial ecology PhD dissertations. Other students in the laboratories of the Principle Investigators, as well as faculty in complementary disciplines, are also conducting research projects in soil microbial ecology. As a result, this project has helped stimulate the development of a "center of excellence" at The Ohio State University focused on soil microbial ecology. Of the two students being supported by this project, one is researching ways of tracking microbial pathogens in the headwaters area of the Sugar Creek Watershed in Ohio. We are investigating the origin and transport of microbial contaminants from non-point sources at a watershed scale and identifying the social and cultural keys that will lead to adoption of good management practices within the watershed. Trial PCR runs with field samples show positive results for Bacteroidales, an indicator microorganism of fecal contamination, with primers that are host
specific for humans, ruminant animals, horse and swine. Preliminary results to optimize conditions to develop quantitative PCR techniques for these host specific markers looks promising. The second student is studying the role of extracellular proteins (elicitins) in sterol acquisition and host recognition by the soybean pathogen Phytophthoa sojae. The demand for soybean is expected to increase because soybean oil (also referred to as biodiesel) has been identified as a more environmentally friendly and sustainable source for energy than coal and fossil fuels. Soybean yield is significantly affected by disease caused by the soilborne pathogen Phytophthora sojae. Currently, planting soybean cultivars containing specific resistance (Rps) genes is the major form for control of the disease caused by P. sojae. However, P. sojae exist in the soil as populations of different races and the planting of disease resistant soybean cultivars is not effective against all races of this pathogen.
Knowledge pertaining to the plant-microbe interactions that occur in soil prior to plant infection by P. sojae is lacking, and understanding these interactions could lead to novel strategies for plant disease management. Using biological growth assays, we have found that P. sojae is 100-fold more sensitive, as determined by an increase in growth, to the presence of a plant sterol than a non-plant sterol. This suggests that Phytopthora has developed tools (e.g. elicitins) that can recognize plant sterols and respond to them to inform the plant pathogen that their host is nearby.
PRODUCTS: None reported.
OUTCOMES: None reported.
DISSEMINATION ACTIVITIES: A web site (http://www.oardc.ohio-state.edu/soilbiolab/) has been developed that has a link titled "Opportunities" on the left side of the page. This describes current research activities and opportunities in the area of soil microbial ecology.
FUTURE INITIATIVES: For the second phase of the microbial source tracking project, we will conduct a highly focused sampling to associate specific land management practices with host source diversity of fecal indicators, detection of select pathogens, and microbial indicator concentrations. Microbial indicator transport through the soil matrix and via surface runoff will be studied using model field plots. In the last phase, we will identify social and cultural keys to land management decisions that impact the potential for microbial contamination in the study watershed. For the study involving the soybean pathogen, Phytophthoa sojae, an experiment has been designed in which elicitins of P. sojae will be labeled with 15N, and then placed into the growth medium of P. sojae with or without added sterols. Following this, tissue of P. sojae will be harvested and analyzed. We expect that signature shifts will be observed only when sterols are added to the growth medium of P. sojae,
indicating the involvement of 15N-elicitins in sterol uptake by Phytophthora. The web site presence for the soil microbial ecology project will be updated in this coming year.
Impacts
Microbial contaminants from non-point sources are often diffuse and difficult to control without knowledge of the specific origin of the pathogen. Better methods to identify pathogen sources and the hosts of the microbial pathogen will lead to a safer food supply and a better understanding of how microbial pathogens move across the landscape. The latter information is important in the case of an accidental or deliberate release of pathogens into the environment. Knowledge pertaining to the plant-microbe interactions that occur in soil prior to plant infection by P. sojae is lacking, and understanding these interactions could lead to novel strategies for plant disease management. This is also true for managing plant diseases caused by other pathogens of the genus Phytophthora.
Publications
- No publications reported this period
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Progress 09/01/05 to 09/01/06
Outputs
Recruitment of Fellows involved placing ads in (1) the CSA Newsletter of the Soil Science Society of America, (2) the American Society for Microbiology newsletter, and (3) on-line on the Historic Black Colleges and Universities (HBCU) web site. A visit by a minority African American student from Lincoln University, a member of the HCBU, to The Ohio State University campus was made in April of 2006. This student ultimately enrolled at another university where she had previously worked during summer months. However, we were successful in recruiting two excellent PhD students into the program and we still have one Fellowship available to be awarded. We would like to reserve this Fellowship for a minority student as that was one of our project goals. At the recent Soil Science Society of American annual meeting in Indianapolis (November, 2006), an invitation was extended to four potential graduate students from Tuskegee University to visit The Ohio State University
(OSU)campus. These students would be ready to enroll at OSU next autumn at the start of a new academic year. Research activities conducted this past year included collection of water samples from upstream and downstream of nine different locations of the Upper Sugar Creek. This included (1) dairy pasture, (2) forested area, (3) town, (4) water treatment plant, (5) pond with water fowl, (6) wetland, (7) barn with horse, (8) pig operation, and (9) septic tank effluent. The DNA from the microbial community from each sample was extracted, purified and then analyzed for Bacteroidales, using probes developed to be specific for the animal host source of the bacteria. Bacteroidales is a fecal indicator bacteria and is an abundant constituent of the animal gastrointestinal tract. GIS data and fecal contamination characteristics data will be combined to observe the effects of land use and agricultural management practices on source, distribution and fate of Bacteroidales
PRODUCTS: No products to report for this first year.
OUTCOMES: A novel set of Bacteroidales nucleic acid probes, that distinguish bacteria on the basis of their animal hosts, have been evaluated using spiked and environmental stream water samples. There was little overlap of signal among the various probes using feces from known animal sources. This suggests it should be possible to determine the animal source of Bacteroidales in environmental samples. Bacteroidales is a fecal indicator bacteria and is an abundant constituent of the animal gastrointestinal tract.
DISSEMINATION ACTIVITIES: An announcement of Fellowship availability was posted at the ASA meeting in November in Indianapolis. Fellowships were also announced in the newsletters of two professional societies (i.e. the Soil Science Society of America and the American Society for Microbiology) and on-line on the Historic Black Colleges and Universities (HBCU) web site.
FUTURE INITIATIVES: Priority will be placed on using the third USDA National Needs Fellowship, still available to this project, for the recruitment of a minority student. There is also interest in developing a more formal soil microbial ecology community of faculty and students at The Ohio State University. This will be a focus of emphasis in the coming year and will probably involve informal seminars, paper reviews, web page development, etc. The course work will be completed for two of the students being supported by the Fellowship program and one has also already passed the General Qualifying Exam. For these two students, there will be an emphasis on collection of research data. One research project will focus on the association of general land use patterns with host source diversity of microbial contaminant indicators in headwater streams of the Upper Sugar Creek watershed by combining stream gage monitoring and complementary bacterial source tracking methods. The other research
project will investigate the role of elicitins in mediating host recognition by Phytophthora via specific binding to host sterols.
Impacts
Most of the activities of this first year of the project related to recruitment of Fellows, of which two PhD students were enrolled this past year. Four other students, not supported by the National Needs Fellowship program, are also pursuing degrees in soil microbial ecology. These are listed as follows: (1) Swati Dey, PhD - Isotope tracking of 13C into microbial communities during plant residue decomposition. Advisor is Dr. Richard Dick (2) David Slocum, MS - Pulsing wetlands and the microbial ecology of methanotrophs. Advisor is Dr. Richard Dick. (3) James Douglas, PhD - Atrazine degradation by microbial communities. Advisor is Dr. Olli Tuovinen. (4) Sougata Bardhan, PhD - Diversity of atrazine degradation genes in the soil microbial community. Advisor is Dr. Warren Dick
Publications
- No publications reported this period
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