Dimensions: Collaborative Research: Functional and genomic diversity in vitamin B1 metabolism and impacts on plankton networks and productivity

Many organisms, from humans to microbes, need to acquire vitamins by ingesting them as food or taking them up directly from the environment. Vitamins are important to individual organisms, but they also have the potential to alter the health and productivity of entire ecosystems. This project will explore the production and consumption of vitamin B1 (thiamin) by planktonic cells that are the base of the ocean food chain.

It will also examine the way that different microorganisms may interact harmoniously and/or competitively in metabolizing thiamin and similar molecules. A network analysis of data will help determine the role that these substances play in controlling microbial biodiversity and photosynthesis in sea water, and the response of microorganisms to changing ocean conditions.

This project will also train postdoctoral scholars, graduate students and underdergraduates, and will support a teacher professional development program that prepares low-income, historically underrepresented, and other educationally underserved students from rural areas to graduate from high school, enroll and succeed in higher education, and pursue STEM careers.

Plankton evolved diverse strategies to acquire thiamin, including salvaging thiamin-related compounds from the environment. This project will: 1) survey metabolic adaptions related to thiamin in plankton, using comparative genomics and evolution (high throughput DNA sequencing); 2) test important functional predictions using cultures and analytical chemistry (chemostats and mass spectrometry); 3) measure plankton interactions in natural and artificially stimulated phytoplankton blooms.

This investigation will join the oceanographic cruises of two major field campaigns in the North Atlantic Ocean. The results will be integrated using several computational approaches to interpret variations in microbial community structure, the role of biochemical, genomic and taxonomic diversity in maintaining biodiversity patterns of today's oceans, as well as potential future oceans, and microbial networks.

Specific aspects of thiamin metabolism pathways will be explored in the context of understanding microbial chemical interactions. These different levels of biodiversity and thiamin cycling will be investigated across transitions between productive phytoplankton blooms and the stratified, oligotrophic conditions that typify the warmer oceans predicted under several environmental change scenarios.