OCE-PRF: The Role of Chemotaxis in Bacterioplankton Ecology

Smriga Steven, Cambridge MA

Investigators

Abstract

Microbial activities at the microscale influence biogeochemical cycles at the ocean-basin scale. Motility and chemotaxis - the sensing of resource gradients and subsequent movement toward them - may enable bacteria to use microscale nutrient resource patches for maintenance and growth. Indeed, some marine bacteria can markedly outperform the classic chemotaxis model organism Escherichia coli, which suggests that advanced chemotaxis strategies have evolved in the marine environment. However, attaining a comprehensive understanding of the prevalence and ecological roles of bacterial chemotaxis remains a major challenge in microbial oceanography, especially given enormous genetic diversity among marine bacteria. This research will tackle this challenge within three overarching hypotheses: 1) The community composition of chemotactic bacteria shifts as motility increases in response to nutrient inputs. 2) Resource gradients trigger the partitioning of a natural bacterial assemblage into subcommunities, as evidence of niche specialization through chemotaxis. 3) Planktonic particles attract ephemeral bacterial swarms, the dynamics of which are dependent on the sensing and chemotactic capabilities of nearby cells. The broader impacts include development of new molecular tools that will be of interest to the research community. The investigator will continue long-term involvement as a volunteer for the National Ocean Science Bowl (NOSB), an outreach program to help high school students from diverse backgrounds prepare for an ocean-themed academic competition. Additional activities include mentoring undergraduate students through an institutional program, teaching, and development of an education videogame on marine microbes. This project is supported under the NSF Ocean Sciences Postdoctoral Research Fellowship (OCE PRF) program, with goals to support novel research by early career scientists and increase the diversity of the U.S. ocean sciences workforce and research community. With OCE-PRF support, this project will enable a promising early career researcher to establish themselves in an independent research career related to ocean sciences and broaden participation of under-represented groups in the ocean sciences.