Microbial Corsortia

Student: Kenice Frank
Department: Biology
Advisor: Slava Epstein

Abstract

Uncultivated bacteria exhibit a large source of unknown secondary metabolites and genes involved in bioremediation and other interesting biotechnological processes. In nature, bacteria populations occur in communities and consortia consisting of assemblies of two (and more) different microorganisms. The bacteria in these consortia interact and perform reactions that no one of the partners can perform alone. Members of consortia cooperate via cross feeding, co-metabolism and cell-to-cell signaling. If the majority of microorganisms rely on a network of beneficial interactions in their natural communities for growth, it would be necessary to uncover how each organism is communicating with others and its environment to achieve comprehensive isolation. The “uncultivated” microorganisms were put in diffusion chambers and incubated in their natural environment. The key was that the chemical diffusion through the semi-permeable wall of the chamber (30 nm pore size) would provide the microorganisms inside with all the naturally occurring components. It allows exchange of chemicals with the environment but restricts movement of cells.

I worked on a project to determine mechanisms by which these uncultivable microbes respond to cultivable microbes from the sediment. I used cultivation-independent methods to assess the diversity of microorganisms in medium with and without the tested growth factor.