Frank Stewart, Assistant Professor
Ph.D., Biology, Harvard University
Office: Environmental Science & Technology (ES&T) 1242
Genome evolution and ecology of microbial symbioses * functional diversity and gene expression in natural microbial communities * molecular evolution through microbial genomics * marine microbiology.
Bacteria and Archaea constitute the overwhelming majority of genetic and metabolic diversity on this planet. To understand these organisms in their native habitats, environmental microbiologists are tasked with two fundamental questions. First, how do ecological and evolutionary processes (e.g., symbiosis, competition, recombination, natural selection) create and structure genetic diversity? Second, how is this genetic diversity linked to the diverse biogeochemical functions of microorganisms in nature?
Our research explores these questions for marine microorganisms, using the tools of genomics and molecular biology. We are particularly interested in how microbial genome evolution and physiology are affected by symbiotic interactions with higher taxa. In tandem with this work, we study free-living microorganisms, as they provide important reference points for understanding symbiont biology and mediate key global biogeochemical cycles in the ocean's water column and sediments. Our research integrates the broad fields of microbiology, molecular evolution, and marine biology. This work has both descriptive and experimental components, and involves a blend of field, molecular, and bioinformatic techniques, the latter focused (primarily) on the analysis of high-throughput sequencing datasets. We welcome inquiries from potential students, post-docs, and collaborators who share these interests.
Sanders JG, Beinart RA, Stewart FJ, DeLong EF, Girguis PR. 2013. Metatranscriptomics reveal differences in in situ energy and nitrogen metabolism among hydrothermal vent snail symbionts. ISME J. In press.
Dimond JL, Kerwin AH, Rotjan R, Sharp K, Stewart FJ, Thornhill DJ. 2013. A simple temperature-based model predicts the upper latitudinal limit of the temperate coral Astrangia poculata. Coral Reefs. (in press)
Ulloa O, Canfield DE, DeLong EF, Letelier RM, Stewart FJ. 2012. Perspective: Microbial oceanography of anoxic oxygen minimum zones. P. Natl. Acad. Sci. USA. 109: 15996-6003.
Stewart FJ, Dalsgaard T, Thamdrup B, Revsbech NP, Ulloa O, Canfield DE, and DeLong EF. Experimental incubations elicit profound changes in community transcription in OMZ bacterioplankton. PLoS ONE. 7: e37118.
Bryant JA, Stewart FJ, Eppley JM, and DeLong EF. 2012. Microbial community phylogenetic and trait diversity decline steeply with depth in a marine oxygen minimum zone. Ecology. 93: 1659-1673.
Stewart FJ, Ulloa O, DeLong EF. 2012. Microbial metatranscriptomics in a permanent marine oxygen minimum zone. Environ. Microbiol. 14:23-40.
Stewart FJ. 2011. Dissimilatory sulfur cycling in oxygen minimum zones: an emerging metagenomics perspective. Biochem. Soc. Trans. 39:1859-1863.
Stewart FJ, Dmytrenko O, DeLong EF, Cavanaugh CM. 2011. Metatranscriptomic analysis of sulfur oxidation genes in the endosymbiont of Solemya velum. Front. Microbiol. 2:134. doi:10.3389/fmicb.2011.00134
Stewart FJ, Sharma AK, Bryant JA, Eppley JM, DeLong EF. 2011. Community transcriptomics reveals universal patterns of protein sequence conservation in microbial communities. Genome Biology. 12:R26.
Stewart FJ, Cavanaugh CM. Pyrosequencing analysis of endosymbiont diversity. 2011. In: de Bruijn FJ (ed.). Handbook of Molecular Microbial Ecology II: Metagenomics in Different Habitats. Wiley-Blackwell.