Progress 01/15/14 to 01/14/18
Outputs
Target Audience:This project is focused on fundamental microbial metabolisms that affect phosphorus mobility, with the goal of understanding these mechanisms for future inclusion in reactive transport models for predictive and management purposes. As such, the primary audience for this stage of work is the research community, with a transition to the agroecosystem modeling community. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?This project, coupled with separate fellowship funding, contributed to four graduate degrees (two M.S. degrees in environmental engineering, one M.S. degree in Biology, and one Ph.D. degree in Biological and Environmental Engineering) and one postdoctoral researcher training. How have the results been disseminated to communities of interest?The results were disseminated to local, regional, and national audiences within the environmental chemistry, biogeochemistry, and wastewater communities through numerous conference presentations. They have also been published in peer-reviewed literature, and this process is ongoing for three more components of the work. Most recently, the results were presented to the Chesapeake Bay modeling community, with the goal of transitioning the fundamental research into inclusion in computational modeling efforts for predictive and management purposes. What do you plan to do during the next reporting period to accomplish the goals?
Nothing Reported
Impacts
What was accomplished under these goals?
Based on results from our field and lab-scale tests, we found significant abundance and diversity of polyphosphate-accumulating organisms (PAOs) in stream biofilms. These microbes contributed to phosphorus retention in the stream, in the form of polyphosphate, even though total stream productivity was constant in our field site. (It was not phosphorus limited.) PAO also contributed to diel phosphorus release from biofilms into the overlying bulk water under anaerobic (dark) conditions. In soil systems, we detected genes associated with polyphosphate formation and hydrolysis, but the results were not conclusive that PAO play an active role in this context. However, we did see evidence of dissimilatory iron reducing bacteria activity during periods of flooded soils that promote lower redox conditions and a shift from oxygen to Fe(III) as an electron acceptor. Accompanying this activity was a release of phosphorus into pore water. These findings indicate the importance of microbial mechanisms in transient phosphorus mobility and speciation, and the need to include these processes in models of phosphorus budgets in agroecosystems.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2016
Citation:
Stockton, M., C. Rojas, S. Saia, M.T. Walter, H. Carrick, A. Buda, J.M. Regan (2016). Effect of polyphosphate-accumulating organisms on phosphorus mobility in variably saturated sand columns. American Geophysical Union Fall Meeting, December 12 16, San Francisco, CA.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2016
Citation:
Saia, S., K. Hofmeister, J.M. Regan, A. Buda, H. Carrick, M. T. Walter (2016). Factors Influencing Divergent Patterns of Phosphorus Availability in NY and PA Biogeochemical Hotspots. American Geophysical Union Fall Meeting, December 12 16, San Francisco, CA.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2016
Citation:
Stockton, M., C. Rojas, S. Saia, S. Taylor, M.T. Walter, H. Carrick, A. Buda, J.M. Regan (2016). Potential role of polyphosphate-accumulating organisms in regulating phosphorus mobility in sand environments subject to aerobic/anaerobic cycles. PSUs 19th Annual Environmental Chemistry and Microbiology Student Symposium, April 8th, University Park, PA.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2016
Citation:
Rojas, C.M., Stockton, M., S. Saia, M.T. Walter, J.M. Regan (2016). Microbial activity controlling iron-phosphorus mobility. 16th International Symposium on Microbial Ecology, August 23rd, Montreal, Canada.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2016
Citation:
Taylor, S. (2016). Polyphosphate Accumulation in Stream Biofilms Evaluated Among Sites of Various Land Use Using an In-Situ Enrichment Experiment in Pennsylvania, USA. M.S. Thesis, Central Michigan University.
- Type:
Journal Articles
Status:
Published
Year Published:
2017
Citation:
Saia, S.M., P.J. Sullivan, J.M. Regan, H.J. Carrick, A.R. Buda, N.A. Locke, M.T. Walter (2017). Evidence for polyphosphate accumulating organism (PAO)-mediated phosphorus cycling in stream biofilms under alternating aerobic/anaerobic conditions. Freshwater Science, 36(2):284-296.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2017
Citation:
Stockton, M. (2017). Changes in Soil Microbial Community Structure Associated with Iron Reduction and Phosphate Release in Soil Microcosms. M.S. Thesis, The Pennsylvania State University, University Park, PA.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2018
Citation:
Regan, J.M., Locke, N.A., C. Rojas, M. Stockton, A.R. Buda, H.J. Carrick, S.M. Saia, M.T. Walter (2018). Identification of Polyphosphate-Accumulating Organisms Contributing to P Cycling in Stream Biofilms. 2018 Chesapeake Community Research and Modeling Symposium. June 13, 2018. Annapolis, MD.
- Type:
Journal Articles
Status:
Other
Year Published:
2018
Citation:
Locke, N.A., A.R. Buda, H.J. Carrick, S.M. Saia, M.T. Walter, J.M. Regan. Classification of bacteria responsible for polyphosphate accumulation in benthic biofilms. In Progress
- Type:
Journal Articles
Status:
Other
Year Published:
2018
Citation:
Saia, S.M., H.J. Carrick, J.M. Regan, A.R. Buda, M.T. Walter. A Cross-Disciplinary Review of Microbial P Cycling for Landscape-Scale Water Quality Management. In Progress
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Progress 01/15/15 to 01/14/16
Outputs
Target Audience:Given the scope of this project, with the initial emphasis on methods development and the identification of polyphosphate-accumulating organisms and dissimilatory iron-reducing bacteria present in benthic biofilms and soils, the main target audience during this reporting period was the scientific community. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided?There were a number of presentations given at institutional, regional, and internation conference over this past reporting period. These are presented in the Major Activities section. A postdoctoral researcher with a PhD in soil science joined the Regan lab, and is providing assistance on the soil column experiments and field work of this project. How have the results been disseminated to communities of interest?We co-organized a session at the 2015 AGU meeting in San Francisco entitled "Human Alteration of the Phosphorus Cycle: Past, Present, and Future". What do you plan to do during the next reporting period to accomplish the goals?We have ongoing activities (described above) designed to accomplish the goals of the project with respect to identifying and characterizing microbial contributions to P mobility in the landscape. These include: - soil columns to study iron-reducing bacteria and PAO - leaf litter exeriments to charactize P release and P sorption associated with biomass decay - field studies to derive correlations among P availability and soil properties/crop management strategies. In addition, our team is considering hosting an international symposium on factors affecting P mobility and retention in agricultural landscapes.
Impacts
What was accomplished under these goals?
We have submitted for publication a manuscript that documents P uptake and release in stream biofilms induced by aerobic and anaerobic conditions, with supporting evidence that polyphosphate-accumulating organisms (PAOs) contribute to the cycling. We also have a manuscript nearing submission that phylogenetically characterizes PAOs in stream biofilms that span a range of environmental conditions. We have ongoing experiments on the fate of P in incubated leaf litter bags. We have ongoing soil column experiments designed to differentiate contributions from iron-reducing bacteria and PAO on P release and uptake under drying and wetting conditions. We have ongoing field studies designed to identify relationships between soil moisture, crop management history, and total reactive phosphorus.
Publications
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2015
Citation:
Locke, N., S. Saia, T. Walter, S. Taylor, H. Carrick, A. Buda, J.M. Regan (2015). Polyphosphate Accumulating Bacteria in Benthic Biofilms. PSUs 18th Annual Environmental Chemistry and Microbiology Student Symposium, April 25th, University Park, PA.
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2015
Citation:
Locke, N., S. Saia, T. Walter, S. Taylor, H. Carrick, A. Buda, J.M. Regan (2015). Polyphosphate Accumulating Bacteria in Benthic Biofilms. Pennsylvania Water Environment Association PennTec, June 2, Lancaster, PA. (Student Research Award to N. Locke.)
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2015
Citation:
Taylor, S.M., J.M. Regan, N. Locke, S. Saia, T. Walter, A.R. Buda, H.J. Carrick (2015). Polyphosphate Accumulation in Stream Biofilms in Pennsylvania. American Geophysical Union Fall Meeting, December 14 18, San Francisco, CA. (Poster)
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2015
Citation:
Taylor, S.M., H.J. Carrick, J.M. Regan, N. Locke, S. Saia, T. Walter, A.R. Buda (2015). Polyphosphate Accumulation in Benthic Biofilms of Pennsylvania Streams. PSUs 18th Annual Environmental Chemistry and Microbiology Student Symposium, April 25th, University Park, PA. (Poster)
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2015
Citation:
Taylor, S.M., H.J. Carrick, J.M. Regan, N. Locke, S. Saia, T. Walter, A.R. Buda (2015). Polyphosphate Accumulation in Benthic Biofilms and Artificial Substrates in Pennsylvania Streams. CMUs Institute for Great Lakes Research Symposium, February 25th. (Poster)
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2015
Citation:
Saia, S.M., J.M. Regan, H.J. Carrick, A.R. Buda, and M.T. Walter (2015). Phosphorus Cycling in Biogeochemical Hot Spots. American Geophysical Union Fall Meeting, December 14 18, San Francisco, CA. (Poster)
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2015
Citation:
Regan, J.M., N. Locke*, S. Saia, T. Walter, S. Taylor, H. Carrick, A. Buda (2015). Bacteria Associated with Polyphosphate Accumulation in Benthic Biofilms. Association of Environmental Engineering and Science Professors Research and Education Conference, June 13-16, New Haven, CT. (Poster)
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2015
Citation:
Regan, J.M., N. Locke*, S. Saia, T. Walter, S. Taylor, H. Carrick, A. Buda (2015). Polyphosphate-accumulating organisms: looking beyond enhanced biological phosphorus removal systems to natural contexts. Invited seminar at Department of Hydraulic and Environmental Engineering, Pontificia Universidad Cat�lica, Santiago, Chile June 24th.
- Type:
Theses/Dissertations
Status:
Published
Year Published:
2015
Citation:
N. Locke (2015). Classification of Polyphosphate-Accumulating Bacteria in Benthic Biofilms. M.S. Thesis.
- Type:
Journal Articles
Status:
Under Review
Year Published:
2015
Citation:
Saia, S.M., P.J. Sullivan, J.M. Regan, H.J. Carrick, A.R. Buda, N.A. Locke, M.T. Walter. Evidence for polyphosphate accumulating organism (PAO)-mediated phosphorus cycling in stream biofilms under alternating aerobic/anaerobic conditions. Submitted for peer-review to Freshwater Science.
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Progress 01/15/14 to 01/14/15
Outputs
Target Audience: Given the scope of this project, with the initial emphasis on methods development and the identification of polyphosphate accumulating organisms present in benthic biofilms and soils, the main target audience during this reporting period was the scientific community. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? This project has involved two MS students (PSU and CMU) and one PhD student (Cornell). The students have been encouraged to present their findings at regional and national conferences. Any important component of this collaboration is the interdisciplinary exchanges at our semi-weekly Skype conference calls, as each partner contributes their unique disciplinary insights on the entire project scope. How have the results been disseminated to communities of interest? We have presented our results at a regional meeting (Environmental Chemistry and Microbiology Student Symposium at PSU) and a national meeting (American Geophysical Union fall meeting). Two manuscripts are in preparation, and we will be submitting a proposal to organize a session at the AGU 2015 fall meeting. What do you plan to do during the next reporting period to accomplish the goals? We will continue our work on identifying PAO in benthic biofilms and soil communities. We also expect to begin the soil column experiments in the coming year, to systematically test the hypothesis that cyclic drying and wetting cycles promote PAO activity. Another activity that has begun in this new reporting period is the testing of P transformations in decaying leaf litter. This will expand our analysis to include the release of P through organic matter decomposition. The field activities will be continued, with additional testing of benthic biofilm response to stream conditions and testing of soil communities.
Impacts
What was accomplished under these goals?
This reporting period was focused on three aspects of the project scope. First, we modified a method of polyphosphate accumulating organism (PAO) separation and detection for application to benthic biofilms. The method consists of dispersing biofilm cells by sonication, DAPI staining that induces a metachromatic shift to polyP-containing cells making them yellow, and separation of those cells using flow cytometry with cell sorting. We collected yellow putative PAO, extracted DNA, and sequenced 16S rRNA gene fragments of these populations from several benthic biofilms collected throughout Pennsylvania across a range of P and productivity conditions. We are presently performing fluorescent in situ hybridization on the samples, using probes designed to target the prominent putative PAO populations from these samples. This will allow us to colocalize polyP and phylogenetic identity. This activity is also expanding to include a series of biofilms collected from the USDA-ARS site being studied in this project, and will soon include the identification of PAO in soils at the site. This work was primarily carried out by the Penn State members of the team. Our second focus was on simulating the diurnal aerobic and anaerobic conditions that are expected to occur in benthic biofilms and monitoring the water chemistry and microbiology changes induced by this cyclic condition. The hypothesis is PAO will liberate phosphate during anaerobic conditions and uptake phosphate during aerobic conditions, as observed and designed for in enhanced biological P removal wastewater treatment systems. This task was accomplished in bench-scale reactors that were alternately sparged with air and nitrogen gas to force the aerobic and anaerobic conditions. We observed the expected trend of increasing orthophosphate concentration during anaerobic conditions, and decreasing concentrations during aerobic conditions. We also saw matching trends in cations known to act as counterions in polyP polymers. Ongoing work in this area involves microscopic and molecular analyses of the biofilms in these reactors. These experiments were conducted by the Cornell team members. Finally, the Central Michigan members initiated a field study at the USDA-ARS project site on benthic biofilm productivity as a function of P flux. This involved placing ceramic tiles in a stream adjacent to several stream flumes (with long-term monitoring data), as well as a series of vials at each location that slowly leached P at different loadings above background. The results showed a correlation between total P and polyP in biofilms and P loading. Ongoing work is characterizing the communities in these biofilms, including fractionating the phototrophic community members based on characteristic spectra for particular groups.
Publications
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2014
Citation:
Locke, N., S. Saia, T. Walter, H. Carrick, A. Buda, J.M. Regan (2014). Polyphosphate-accumulating bacteria identification for benthic biofilms from agricultural watersheds. American Geophysical Union Fall Meeting, December 15 19, San Francisco, CA. (Poster)
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2014
Citation:
Saia, S.M., N.A. Locke, J.M. Regan, H.J. Carrick, A.R. Buda, and M.T. Walter (2014). How do changes in dissolved oxygen concentration influence microbially-controlled phosphorus cycling in stream biofilms? American Geophysical Union Fall Meeting, December 15 19, San Francisco, CA. (Poster)
- Type:
Conference Papers and Presentations
Status:
Other
Year Published:
2014
Citation:
Locke, N., S. Saia, T. Walter, H. Carrick, A. Buda, J.M. Regan (2014). Identification of Polyphosphate-Accumulating Bacteria in Agricultural Watershed Soils and Biofilms Subject to Anaerobic/Aerobic Cycles. PSUs 17th Annual Environmental Chemistry and Microbiology Student Symposium, March 28th, University Park, PA. (Poster)
- Type:
Other
Status:
Other
Year Published:
2014
Citation:
Nicholas Locke (2014). Metagenomic analysis of naturally occurring polyphosphate accumulating bacteria in Pennsylvanian streams. Kappe Environmental Engineering Seminar, November 12.
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