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Research Spending & Results

Award Detail

Awardee:GEORGIA TECH RESEARCH CORPORATION
Doing Business As Name:Georgia Tech Research Corporation
PD/PI:
  • Frank J Stewart
  • (404) 894-5819
  • frank.stewart@biology.gatech.edu
Award Date:02/13/2012
Estimated Total Award Amount: $ 1,210,901
Funds Obligated to Date: $ 1,210,901
  • FY 2012=$233,043
  • FY 2015=$248,111
  • FY 2013=$236,337
  • FY 2014=$242,109
  • FY 2016=$251,301
Start Date:02/15/2012
End Date:01/31/2020
Transaction Type:Grant
Agency:NSF
Awarding Agency Code:4900
Funding Agency Code:4900
CFDA Number:47.050
Primary Program Source:040100 NSF RESEARCH & RELATED ACTIVIT
Award Title or Description:CAREER: A phylogenetic and functional understanding of microbial sulfur cycling in oxygen minimum zones
Federal Award ID Number:1151698
DUNS ID:097394084
Parent DUNS ID:097394084
Program:BIOLOGICAL OCEANOGRAPHY
Program Officer:
  • Daniel J. Thornhill
  • (703) 292-8143
  • dthornhi@nsf.gov

Awardee Location

Street:Office of Sponsored Programs
City:Atlanta
State:GA
ZIP:30332-0420
County:Atlanta
Country:US
Awardee Cong. District:05

Primary Place of Performance

Organization Name:Georgia Institute of Technology
Street:225 North Ave NW
City:Atlanta
State:GA
ZIP:30332-0002
County:Atlanta
Country:US
Cong. District:05

Abstract at Time of Award

Oxygen concentration significantly impacts the community structure and function of marine ecosystems. In waters with low oxygen, including the major marine oxygen minimum zones (OMZs), biological diversity is dominated by a complex community of microorganisms whose anaerobic metabolisms mediate key steps in global nitrogen and carbon cycles. Surprisingly, new evidence indicates that OMZs also support diverse microorganisms capable of utilizing inorganic sulfur compounds for energy metabolism. This assemblage appears to include both sulfur-oxidizing autotrophs and sulfate-reducing heterotrophs, suggesting an active sulfur cycle with potentially substantial roles in organic carbon input and mineralization, as well as critical links to the OMZ nitrogen cycle. Our knowledge of the microorganisms driving OMZ sulfur cycling is based largely on the metagenome of a single bacterial lineage (SUP05) and on surveys of diagnostic marker genes, which have thus far targeted only a subset of the diverse low-oxygen regions in the global ocean. The metabolic diversity, activity, and biogeographic distribution of sulfur-metabolizing microorganisms in the OMZ water column remain largely unexplored. This project uses an integrated molecular and experimental approach to critically examine the physiological and phylogenetic basis of microbial sulfur cycling in oxygen minimum zones. Combining targeted metagenomics with gene expression profiling, microcosm sulfur-addition experiments, and enrichment culturing, the PI will characterize sulfur-metabolizing microorganisms in two oceanographically and ecologically distinct low-oxygen regions: the Eastern Tropical North Pacific (ETNP) OMZ off Mexico, which represents the largest permanent OMZ in the world, and the seasonally hypoxic "dead zone" in the Gulf of Mexico (GOM). Specifically, they will test the hypotheses that sulfur- oxidizing and -reducing bacterioplankton 1) are abundant and transcriptionally active in the ETNP OMZ, 2) are minor components of the hypoxic GOM, but increase in activity and abundance when oxygen decreases and sulfide increases, and 3) exhibit biogeographic variation in functional gene content and phylogenetic diversity over vertical profiles, among OMZs, and in response to environmental gradients. OMZs are predicted to expand in response to future climate change, making it imperative to holistically understand the biology of low-oxygen regions. This project will establish a comprehensive framework for studying the genomics and physiology of an ecologically important, but poorly characterized, functional group(s) of marine bacterioplankton in OMZs. Results will be analyzed relative to existing metagenomic data from the permanent Eastern Tropical South Pacific (ETSP) OMZ, and a second seasonal OMZ (Saanich Inlet), thereby establishing a comparative basis for describing the ecological distribution of pelagic sulfur-metabolizing microorganisms and their relative role in OMZ community metabolism. Broader Impacts Marine science research will be used as a platform for enhancing science education across multiple academic levels. A Summer Workshop in Marine Science (SWIMS) will be developed in collaboration with K-12 educators and teacher-development experts at Georgia Tech. The 5-day SWIMS program, which includes 2 days at the Skidaway Institute of Oceanography, will engage graduate students and Georgia Tech researchers in training local teachers to merge key topics in marine science with new national standards in middle school Earth Science education. In addition, through a partnership with Morehouse and Spelman Colleges, this project funds summer internships to enhance representation of minority students in undergraduate marine science and bioinformatics research. A PI-graduate student working group is to be established at Georgia Tech to develop and implement new guidelines for training in the cross-disciplinary field of marine genomics. A new course will be created at Georgia Tech, Writing for Scientists, to enhance the professional development of graduate students. It will use structured, peer-driven exercises to equip students with the critical writing and speaking skills necessary for success in science - such a course is critically lacking at Georgia Tech. Through the activities outlined above, this CAREER project will not only establish a research group dedicated to characterizing an ecologically significant, but cryptic, component of the marine microbial ecosystem, but will also develop a strong foundation through which the PI can use the results of his work to train and motivate future generations of marine scientists.

Publications Produced as a Result of this Research

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Garcia-Robledo E, Padilla CC, Aldunate M, Paulmier A, Gregori G, Stewart FJ, Ulloa O, Revsbech NP "Cryptic oxygen cycling in anoxic marine zones" Proceedings of the National Academy of Sciences of the USA, v., 2017, p..

Mandric I, Knyazev S, Padilla C, Stewart F, Mandoiu II, Zelikovsky A "Metabolic analysis of metatranscriptomic data from planktonic communities." Bioinformatics Research and Applications. ISBRA 2017. Lecture Notes in Computer Science, vol 10330, v., 2017, p.. doi:10.1007/978-3-319-59575-7_41 

Tsementzi D, Wu J, Deutsch S, Nath N, Rodriguez-R LM, Burns AS, Ranjan P, Sarode N, Malmstrom RR, Padilla CC, Stone BK, Bristow LA, Larsen M, Glass JB, Thamdrup B, Woyke T, Konstantinidis KT, Stewart FJ "SAR11 bacteria linked to ocean anoxia and nitrogen loss" Nature, v., 2016, p..

Glass JB, Kretz CB, Ganesh S, Ranjan P, Seston SL, Buck KN, Landing WL, Morton PL, Moffett JW, Giovannoni SJ, Vergin KL, Stewart FJ "Meta-omic signatures of microbial metal and nitrogen cycling in marine oxygen minimum zones" Frontiers in Microbiology, v., 2015, p..

Ganesh S, Bristow LA, Larsen M, Sarode N, Thamdrup B, Stewart FJ. "Size-fraction partitioning of community gene transcription and nitrogen metabolism in a marine oxygen minimum zone." The ISME Journal, v.9, 2015, p.2682. doi:10.1038/ismej.2015.44 

Ganesh S, Bertagnolli AD, Bristow LA, Padilla CC, Blackwood N, Aldunate M, Bourbonnais A, Altabet MA, Woyke T, Ulloa O, Konstantinidis KK, Thamdrup B, Stewart FJ "Genomic evidence for the use of alternative nitrogen substrates by anammox bacteria" The ISME Journal., v., 2018, p..

Padilla CC, Bertagnolli AD, Bristow LA, Sarode N, Glass JB, Thamdrup B, Stewart FJ "Metagenomic binning identifies a transcriptionally active Gammaproteobacterium linking methanotrophy to partial denitrification in an anoxic oxygen minimum zone" Frontiers in Marine Science, v., 2017, p.. doi:10.3389/fmars.2017.00023 

Parris DJ, Ganesh S, Edgcomb VP, DeLong EF, Stewart FJ "Microbial eukaryote diversity in the marine oxygen minimum zone off northern Chile" Frontiers in Microbiology, v., 2014, p.. doi:10.3389/fmicb.2014.00543 

Padilla C, Ganesh S, Gantt S, Huhman A, Parris DJ, Sarode N, Stewart FJ "Standard filtration practices may significantly distort planktonic microbial diversity estimates" Frontiers in Microbiology, v., 2015, p.. doi:10.3389/fmicb.2015.00547 

Parris DJ, Ganesh S, Edgcomb VP, DeLong EF, Stewart FJ "Microbial eukaryote diversity in the marine oxygen minimum zone off northern Chile" Frontiers in Microbiology, v.5, 2014, p.543. doi:10.3389/fmicb.2014.00543 

Stewart FJ "Preparation of microbial community cDNA for metatranscriptomic analysis in marine plankton" Methods in Enzymology, v., 2013, p..

Bristow LA, Sarode N, Cartee J, Thamdrup B, Stewart FJ. "Metagenomics and biogeochemical analysis of nitrite accumulation in the Gulf of Mexico hypoxic zone." Limnology & Oceanography, v.60, 2015, p.1733. doi:10.1002/lno.10130 

Duret MT, Paciadaki MG, Stewart FJ, Sarode N, Christaki U, Monchy S, Edgcomb VP "Size-fractionated diversity of eukaryotic microbial communities in the Eastern Tropical North Pacific oxygen minimum zone" FEMS Microbiology Ecology, v., 2015, p.. doi:10.1093/femsec/fiv037 

Padilla CC, Bristow LA, Sarode N, Garcia-Robledo E, Gómez Ramírez E, Benson CR, Bourbonnais A, Altabet MA, Girguis PR, Thamdrup B, Stewart FJ "NC10 bacteria in marine oxygen minimum zones" The ISME Journal, v.10, 2016, p.2067. doi:10.1038/ismej.2015.262 

Beckler JS, Kiiazis N, Rabouille C, Stewart FJ, Taillefert M "Importance of microbial iron reduction in deep sediments of river-dominated continental margins." Marine Chemistry, v., 2016, p.. doi:10.1016/j.marchem.2015.12.003 

Beckler JS, Kiriazis N, Rabouille C, Stewart FJ, Taillefert M "Importance of microbial iron reduction in deep sediments of river-dominated continental-margins" Marine Chemistry, v., 2016, p..

Larsen M, Lehner P, Borisov SM, Klimant I, Fischer J, Stewart FJ, Canfield DE, Glud RN "In situ quantification of ultra-low O2 concentrations in oxygen minimum zones" Limnology & Oceanography Methods, v., 2016, p.. doi:10.1002/lom3.10126 

Ganesh S, Bertagnolli AD, Bristow LA, Padilla CC, Blackwood N, Aldunate M, Bourbonnais A, Altabet MA, Woyke T, Ulloa O, Konstantinidis KK, Thamdrup B, Stewart FJ "Genomic evidence for the use of alternative nitrogen substrates by anammox bacteria" The ISME Journal, v., 2018, p..

Kitzinger K, Padilla CC, Marchant HK, Hach PF, Herbold CW, Kidane AT, Könneke M, Littmann S, Mooshammer M, Niggemann J, Petrov S, Richter A, Stewart FJ, Wagner M, Kuypers MMM, Bristow LA "Cyanate and urea are substrates for nitrification by Thaumarchaeota in the marine environment" Nature Microbiology, v., 2019, p..

Ganesh S, Bristow LA, Larsen M, Sarode N, Thamdrup B, Stewart FJ "Size-fraction partitioning of community gene transcription and nitrogen metabolism in a marine oxygen minimum zone" The ISME Journal, v., 2015, p.. doi:10.1038/ismej.2015.44 

Padilla C, Ganesh S, Gantt S, Huhman A, Parris DJ, Sarode N, Stewart FJ "Standard filtration practices may significantly distort planktonic microbial diversity estimates." Frontiers in Microbiology, v.6, 2015, p.547. doi:10.3389/fmicb.2015.00547 

Larsen M, Lehner P, Borisov SM, Klimant I, Fischer J, Stewart FJ, Canfield DE, Glud RN "In situ quantification of ultra-low O2 concentrations in oxygen minimum zones." Limnology & Oceanography Methods, v.14, 2016, p.784. doi:10.1002/lom3.10126 

Stewart FJ "Preparation of microbial community cDNA for metatranscriptomic analysis in marine plankton" Methods in Enzymology, v., 2013, p.. doi:10.1016/B978-0-12-407863-5.00010-1 

Padilla CC, Bristow LA, Sarode N, Garcia-Robledo E, Go?mez Rami?rez E, Benson CR, Bourbonnais A, Altabet MA, Girguis PR, Thamdrup B, Stewart FJ "NC10 bacteria in marine oxygen minimum zones" The ISME Journal, v., 2016, p.. doi:10.1038/ismej.2015.262 

Larsen M, Lehner P, Borisov SM, Klimant I, Fischer J, Stewart FJ, Canfield DE, Glud RN "In situ quantification of ultra-low O2 concentrations in oxygen minimum zones" Limnology & Oceanography Methods, v., 2016, p..

Stewart FJ "Preparation of microbial community cDNA for metatranscriptomic analysis in marine plankton" Methods in Enzymology, v.531, 2013, p.187. doi:10.1016/B978-0-12-407863-5.00010-1 

Stewart FJ "Commentary: Where the genes flow" Nature Geoscience, v.6, 2013, p.688. doi:10.1038/ngeo1939 

Ganesh S, Parris DJ, DeLong EF, Stewart FJ "Metagenomic analysis of size-fractionated picoplankton in a marine oxygen minimum zone" he ISME Journal, v., 2014, p.. doi:10.1038/ismej.2013.144 

Seston SL, Beinart R, Sarode N, Shockey AC, Ranjan P, Ganesh S, Girguis PR, Stewart FJ "Metatranscriptional response of chemoautotrophic Ifremeria nautilei endosymbionts to differing sulfur regimes" Frontiers in Microbiology, v., 2016, p..

Kitzinger K, Padilla CC, Marchant HK, Hach PF, Herbold CW, Kidane AT, Könneke M, Littmann S, Mooshammer M, Niggemann J, Petrov S, Richter A, Stewart FJ, Wagner M, Kuypers MMM, Bristow LA. "Cyanate and urea are substrates for nitrification by Thaumarchaeota in the marine environment" Nature Microbiology, v., 2019, p..

Parris DJ, Ganesh S, Edgcomb VP, DeLong EF, Stewart FJ "Microbial eukaryote diversity in the marine oxygen minimum zone off northern Chile" Frontiers in Microbiology, v., 2014, p.. doi:10.3389/fmicb.2014.00543 

Bertagnolli AD, Stewart FJ "Microbial niches in marine oxygen minimum zones" Nature Reviews Microbiology, v., 2018, p..

Bertagnolli AD, Stewart FJ "Microbial niches in marine oxygen minimum zones." Nature Reviews Microbiology, v.16, 2018, p..

Thamdrup B, Steinsdóttir HGR, Bertagnolli AD, Patin NV, Padilla CC, García-Robledo E, Bristow LA, Stewart FJ "Anaerobic methane oxidation is an important sink for methane in the ocean’s largest oxygen minimum zone" Limnology & Oceanography, v., 2019, p..

Stewart FJ "Where the genes flow" Nature Geoscience, v., 2013, p.. doi:10.1038/ngeo1939 

Beckler JS, Kiiazis N, Rabouille C, Stewart FJ, Taillefert M "Importance of microbial iron reduction in deep sediments of river-dominated continental margins" Marine Chemistry, v.178, 2016, p.22. doi:10.1016/j.marchem.2015.12.003 

Glass JB, Kretz CB, Ganesh S, Ranjan P, Seston SL, Buck KN, Landing WM, Morton PL, Moffett JW, Giovannoni SJ, Vergin KL, Beszteri B, Stewart FJ "Meta-omic signatures of microbial metal and nitrogen cycling in marine oxygen minimum zones" Frontiers in Microbiology, v., 2015, p.. doi:10.3389/fmicb.2015.00998 

Stewart FJ "Commentary: Where the genes flow" Nature Geoscience, v.6, 2013, p.688.

Ganesh S, Bristow LA, Larsen M, Sarode N, Thamdrup B, Stewart FJ "Size-fraction partitioning of community gene transcription and nitrogen metabolism in a marine oxygen minimum zone" The ISME Journal, v., 2015, p.. doi:10.1038/ismej.2015.44 

Ganesh S, Parris DJ, DeLong EF, Stewart FJ. "Metagenomic analysis of size-fractionated picoplankton in a marine oxygen minimum zone" The ISME Journal, v.8, 2014, p.187. doi:10.1038/ismej.2013.144 

Duret MT, Pachiadaki MG, Stewart FJ, Sarode N, Christaki U, Monchy S, Edgcomb VP "Size-fractionated diversity of eukaryotic microbial communities in the Eastern Tropical North Pacific oxygen minimum zone" FEMS Microbiology Ecology, v., 2015, p..

Bertagnolli AD, Padilla CC, Glass JB, Thamdrup B, Stewart FJ "Metabolic potential and in situ activity of marine Marinimicrobia bacteria in an anoxic water column" Environmental Microbiology, v., 2017, p..

Bertagnolli AD, Padilla CC, Glass JB, Thamdrup B, Stewart FJ "Metabolic potential and in situ activity of marine Marinimicrobia bacteria in an anoxic water column" Environmental Microbiology, v., 2017, p.. doi:10.1111/1462-2920.13879 

Vik DR, Roux S, Brum JR, Bolduc B, Emerson JB, Padilla CC, Stewart FJ, Sullivan MB "Putative Archaeal viruses from the mesopelagic ocean" PeerJ, v., 2017, p..

Bristow LA, Sarode N, Cartee J, Thamdrup B, Stewart FJ "Metagenomics and biogeochemical analysis of nitrite accumulation in the Gulf of Mexico hypoxic zone" Limnology & Oceanography, v., 2015, p.. doi:10.1002/lno.10130 

Parris DJ, Ganesh S, Edgcomb VP, DeLong EF, Stewart FJ "Microbial eukaryote diversity in the marine oxygen minimum zone off northern Chile" Frontiers in Microbiology, v., 2014, p..

Ganesh S, Bristow LA, Larsen M, Sarode N, Thamdrup B, Stewart FJ "Size-fraction partitioning of community gene transcription and nitrogen metabolism in a marine oxygen minimum zone" The ISME Journal, v., 2015, p..

Mandric I, Knyazev S, Padilla C, Stewart F, Mandoiu II, Zelikovsky A "Metabolic analysis of metatranscriptomic data from planktonic communities" Bioinformatics Research and Applications. ISBRA 2017. Lecture Notes in Computer Science, vol 10330, v., 2017, p..

Vik DR, Roux S, Brum JR, Bolduc B, Emerson JB, Padilla CC, Stewart FJ, Sullivan MB "Putative Archaeal viruses from the mesopelagic ocean" PeerJ, v., 2017, p.. doi:10.7717/peerj.3428 

Bristow LA, Sarode N, Cartee J, Caro-Quintero A, Thamdrup B, Stewart FJ "Biogeochemical and metagenomic analysis of nitrite accumulation in the Gulf of Mexico hypoxic zone" Limnology & Oceanography, v., 2015, p..

Seston SL, Beinart R, Sarode N, Shockey AC, Ranjan P, Ganesh S, Girguis PR, Stewart FJ "Metatranscriptional response of chemoautotrophic Ifremeria nautilei endosymbionts to differing sulfur regimes" Frontiers in Microbiology, v., 2016, p.. doi:10.3389/fmicb.2016.01074 

Padilla CC, Ganesh S, Gantt S, Huhman A, Parris DJ, Sarode N, Stewart FJ "Standard filtration practices may significantly distort planktonic microbial diversity estimates" Frontiers in Microbiology, v., 2015, p..

Tsementzi D, Wu J, Deutsch S, Nath N, Rodriguez-R LM, Burns AS, Ranjan P, Sarode N, Malmstrom RR, Padilla CC, Stone BK, Bristow LA, Larsen M, Glass JB, Thamdrup B, Woyke T, Konstantinidis KT, Stewart FJ "SAR11 bacteria linked to ocean anoxia and nitrogen loss" Nature, v., 2016, p.. doi:10.1038/nature19068 

Padilla CC, Bertagnolli AD, Bristow LA, Sarode N, Glass JB, Thamdrup B, Stewart FJ "Metagenomic binning recovers a transcriptionally active Gammaproteobacterium linking methanotrophy to partial denitrification in an anoxic oxygen minimum zone" Frontiers in Marine Science, v., 2017, p..

Padilla CC, Bertagnolli AD, Bristow LA, Sarode N, Glass JB, Thamdrup B, Stewart FJ "Metagenomic binning identifies a transcriptionally active Gammaproteobacterium linking methanotrophy to partial denitrification in an anoxic oxygen minimum zone" Frontiers in Marine Science, v., 2017, p.. doi:doi: 10.3389/fmars.2017.00023 

Ganesh S, Parris DJ, DeLong EF, Stewart FJ "Metagenomic analysis of size-fractionated picoplankton in a marine oxygen minimum zone" The ISME Journal, v., 2014, p..

Padilla CC, Bristow LA, Sarode N, Garcia-Robledo E, Gomez Ramirez E, Benson CR, Bourbonnais A, Altabet MA, Girguis PR, Thamdrup B, Stewart FJ "NC10 bacteria in marine oxygen minimum zones" The ISME Journal, v., 2016, p..

Canfield DE, Kraft B, Löscher C, Boyle RA, Thamdrup B, Stewart FJ "The regulation of oxygen to low concentrations in marine oxygen-minimum zones" Journal of Marine Research, v., 2019, p..

Seston SL, Beinart R, Sarode N, Shockey AC, Ranjan P, Ganesh S, Girguis PR, Stewart FJ. "Metatranscriptional response of chemoautotrophic Ifremeria nautilei endosymbionts to differing sulfur regimes." Frontiers in Microbiology, v.7, 2016, p.1074. doi:doi.org/10.3389/fmicb.2016.01074 

Stewart FJ "Preparation of microbial community cDNA for metatranscriptomic analysis in marine plankton" Methods in Enzymology, v., 2013, p.. doi:10.1016/B978-0-12-407863-5.00010-1 

Glass JB, Kretz CB, Ganesh S, Ranjan P, Seston SL, Buck KN, Landing WM, Morton PL, Moffett JW, Giovannoni SJ, Vergin KL, Beszteri B, Stewart FJ. "Meta-omic signatures of microbial metal and nitrogen cycling in marine oxygen minimum zones." Frontiers in Microbiology, v.6, 2015, p.998. doi:10.3389/fmicb.2015.00998 

Bristow LA, Sarode N, Cartee J, Thamdrup B, Stewart FJ "Metagenomics and biogeochemical analysis of nitrite accumulation in the Gulf of Mexico hypoxic zone" Limnology and Oceanography, v., 2015, p.. doi:10.1002/lno.10130 

Glass JB, Kretz CB, Ganesh S, Ranjan P, Seston SL, Buck KN, Landing WM, Morton PL, Moffett JW, Giovannoni SJ, Vergin KL, Beszteri B, Stewart FJ. "Meta-omic signatures of microbial metal and nitrogen cycling in marine oxygen minimum zones." Frontiers in Microbiology, v., 2015, p.. doi:10.3389/fmicb.2015.00998 

Stewart FJ "Where the genes flow" Nature Geoscience, v., 2013, p.. doi:10.1038/ngeo1939 

Ganesh S, Parris DJ, DeLong EF, Stewart FJ "Metagenomic analysis of size-fractionated picoplankton in a marine oxygen minimum zone." The ISME Journal, v.8, 2014, p.187. doi:10.1038/ismej.2013.144 

Stewart FJ "Where the genes flow" Nature Geoscience, v., 2013, p..

Burns AS, Padilla CC, Pratte ZA, Gilde K, Regensburger M, Hall E, Dove ADM, Stewart FJ "Broad phylogenetic diversity associated with nitrogen loss through sulfur oxidation in a large public marine aquarium" Applied and Environmental Microbiology, v., 2018, p..

Kitzinger K, Marchant HK, Bristow LA, Herbold CW, Padilla CC, Kidane AT, Littmann S, Daims H, Pjevac P, Stewart FJ, Wagner M, Kuypers MMM "Single cell analyses reveal contrasting life strategies of the two main nitrifiers in the ocean" Nature Communications, v., 2020, p..

Ganesh S, Parris DJ, DeLong EF, Stewart FJ "Metagenomic analysis of size-fractionated picoplankton in a marine oxygen minimum zone" The ISME Journal, v., 2014, p.. doi:10.1038/ismej.2013.144 

Garcia-Robledo E, Padilla CC, Aldunate M, Paulmier A, Gregori G, Stewart FJ, Ulloa O, Revsbech NP "Cryptic oxygen cycling in anoxic oxygen minimum zones" Proceedings of the National Academy of Sciences of the USA, v., 2017, p.. doi:10.1073/pnas.1619844114 

Stewart FJ "Preparation of microbial community cDNA for metatranscriptomic analysis in marine plankton." Methods in Enzymology, v.531, 2013, p.187. doi:10.1016/B978-0-12-407863-5.00010-1 

Tsementzi D, Wu J, Deutsch S, Nath N, Rodriguez-R LM, Burns AS, Ranjan P, Sarode N, Malmstrom RR, Padilla CC, Stone BK, Bristow LA, Larsen M, Glass JB, Thamdrup B, Woyke T, Konstantinidis KT, Stewart FJ. "SAR11 bacteria linked to ocean anoxia and nitrogen loss" Nature, v.536, 2016, p.179. doi:10.1038/nature19068 

Padilla C, Ganesh S, Gantt S, Huhman A, Parris DJ, Sarode N, Stewart FJ "Standard filtration practices may significantly distort planktonic microbial diversity estimates" Frontiers in Microbiology, v., 2015, p.. doi:10.3389/fmicb.2015.00547 

Parris DJ, Ganesh S, Edgcomb VP, DeLong EF, Stewart FJ "Microbial eukaryote diversity in the marine oxygen minimum zone off northern Chile" Frontiers in Microbiology, v.5, 2014, p.. doi:10.3389/fmicb.2014.00543 


Project Outcomes Report

Disclaimer

This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.

The overarching goal of this project was to understand how changes in ocean oxygen content affect the diversity and metabolism of microbial communities. Knowledge of these effects is important for predicting the flow of matter and energy through marine food webs. Changes in matter and energy flow at the microbial level may in turn affect levels (e.g., fish) that are of relevance to human economic and recreational activities. This project therefore contributes data that may enable more accurate predictions of how large shifts in ocean properties affect social and economic systems.

The first sub-goal of this research was to characterize the microorganisms that use the essential elements of sulfur and nitrogen to generate energy.  This work involved four field campaigns (research cruises) to two physically and chemically distinct low oxygen regions, the permanently anoxic (no detectable oxygen) oxygen minimum zone (OMZ) of the Eastern Tropical North Pacific off Mexico and the seasonally hypoxic (low but detectable oxygen) OMZ of the Gulf of Mexico (Figure 1). Our analyses involved experiments to assess how seawater microbes respond metabolically to shifts in oxygen, sulfur, and nitrogen content, as well as extensive computational analyses of microbial DNA and RNA sequences.  The computational analyses were particularly important for identifying both novel organisms and metabolic processes.  This work, for example, identified novel clades of OMZ bacteria that oxidize sulfur compounds or the greenhouse gas methane, and do so by linking this metabolism to the removal of nitrogen from the ecosystem.  This work also identified previously unrecognized adaptations to low oxygen by the world's most abundant organism, a bacterium called SAR11.  A secondary component of sub-goal 1 was to understand how these unique OMZ microbes are distributed in the environment.  Specifically, we assessed how OMZ microbes, and the chemical processes they mediate, differ depending on whether microbes are living attached to the surfaces of marine particles (such as zooplankton or phytoplankton cells, or sediments) versus living freely as individual cells in the water column.  Our work on this question identified significant differences in microbial cycling of nitrogen and sulfur between these environments.  This finding helped identify ecological interactions (e.g., between microbes) and confirmed that, as in other ecosystems, we need to understand the microscale distribution of microorganisms in order to fully understand their contribution to chemical and nutrient cycling as oxygen levels change.  This research has thus far produced 21 published journal articles and 2 published book chapters; trained 8 Georgia Tech undergraduates, 4 Georgia Tech graduate students, 4 postdocs, 2 high school teachers, and 5 summer Research Experiences for Undergraduates (REU) students from non-research institutions; and funded 4 research cruises, creating research opportunities for 12 different labs, including those of international collaborators.  Data associated with this project are archived via the BCO-DMO website for award 1151698.

The second major sub-goal of our project was to establish an educational framework that uses marine research to enhance science curricula in middle and high schools.  This goal focused specifically on developing and running a teacher training workshop at Georgia Tech, the Summer Workshop in Marine Science (SWiMS) (Figure 2). The workshop involves a week of hands?on lab and learning activities at Georgia Tech and at the Georgia Marine Institute on Sapelo Island, followed by assessment of classroom outcomes throughout the following school year.  SWiMS was developed using resources and personnel (including local high school teachers) associated with this grant, and was implemented for the first time in 2015.  SWiMS has run consecutively for 5 summers and has provided training for over 90 Georgia educators (2015-2019), primarily in high?needs districts around Atlanta. The development of SWiMS also provided summer internships at Georgia Tech for 5 Atlanta-area high school science teachers.  Plans are in place to continue offering SWiMS in conjunction with the Center for Education Integrating Science, Mathematics, and Computing (CEISMC) and the recently launched graduate program in Ocean Science and Engineering at Georgia Tech. 

 

 

 


Last Modified: 06/11/2020
Modified by: Frank J Stewart

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