Post-doctoral research associateDiatoms under the microscope
office: (206) 685-4196
Marine microbes are a critical component of the ocean ecosystem, principally through their influence on energy and nutrient flow. I am interested in interactions among marine microbes, specifically, how microbes use organic compounds as metabolic currencies and signaling molecules to form the basis for different trading alliances.
Oceanic primary production, carried out predominantly by unicellular phytoplankton, generates one of the largest reservoirs of carbon on Earth. About half of this fixed carbon is subsequently degraded by heterotrophic bacteria, a transfer that accounts for the largest flux of carbon through the ocean. The chemical makeup of this carbon pool is inherently complex, a product of the diversity of the hundreds of thousands of different planktonic organisms that make up seawater communities. Thus, compounds important in this trophic link are poorly known.
To explore metabolite exchange in bacterial-phytoplankton interactions, our lab has employed a model microbial system approach where we co-culture marine bacteria and diatoms together and use gene expression and metabolite analyses to assay for compounds passed between them (see Amin et al., 2015 & Durham et al., 2015). So far, we have detected exchange of sulfonated substrates and auxin-like signaling molecules between bacteria and diatoms. Genes for biosynthesis and degradation of these organic compounds have limited distribution among bacterioplankton, suggesting that these sulfonated substrates and signaling molecules underlie targeted interactions between mutualistic bacteria and diatoms.
I am currently using a combination of laboratory- and field-based measurements to study sulfonates and auxins in terms of their contribution to marine organic matter flux, their taxonomically driven spatiotemporal dynamics, and their roles in ecosystem interdependencies.
Collection of plankton onboard the UW's R/V Thomas G. ThompsonExtraction of plankton metabolites in the lab
Photo credit: Robyn Von Swank
Ph.D., Microbiology, University of Georgia, 2014
B.S., Biology, Virginia Tech, 2008
Amin SA, Hmelo LR, van Tol HM, Durham BP, Carlson LT, Heal KR, Morales RL, Berthiaume CT, Parker MS, Djunaedi B, Ingalls AE, Parsek MR, Moran MA, Armburst EV. 2015. Interaction and signalling between a cosmopolitan phytoplankton and associated bacteria. Nature 522:98-101.
Varaljay VA, Robidart J, Preston CM, Gifford SM, Durham BP, Burns AS, Ryan JP, Marin R III, Kiene RP, Zehr JP, Scholin CA, Moran MA. 2015. Single-taxon field measurements of bacterial gene regulation controlling DMSP fate. ISME Journal 9:1677-1686.
Durham BP, Sharma S, Luo H, Smith CB, Amin SA, Bender SJ, Dearth SP, Van Mooy BAS, Campagna SR, Kujawinski EB, Armbrust EV, Moran MA. 2015. Cryptic carbon and sulfur cycling between surface ocean plankton. Proc Natl Acad Sci USA 112:453-457.
Durham BP, Grote J, Whittaker KA, Bender SJ, Luo H, Grim SL, Brown JM, Casey JR, Dron A, Florez-Leiva L, Krupke A, Luria CM, Mine AH, Pather S, Talarmin A, Wear EK, Weber TS, Wilson JM, Church MJ, DeLong EF, Karl DM, Steward GF, Eppley JM, Kyrpides NC, Schuster S, Rappé MS. 2014. Draft genome sequence of marine alphaproteobacterial strain HIMB11, the first cultivated representative of a unique lineage within the Roseobacter clade possessing a remarkably small genome. Standards in Genomic Sciences 9:632-645.
Moran MA, Satinsky B, Gifford SM, Luo H, Rivers A, Chan LK, Meng J, Durham BP, Shen C, Varaljay VA, Smith CB, Yager PL, Hopkinson BM. 2013. Sizing up metatranscriptomics. ISME Journal 7:237-243.