Probing the biological chemistry of exchange and sharing of thiamin and purine biosynthesis pathway intermediates within Escherichia coli synthetic cocultures

Abstract

Microbes are known to exchange metabolic intermediates among each other. Though understanding the complex network of metabolic interactions between microbes remains to be studied extensively. We created synthetic consortia of thiamin and purine biosynthesis mutants of Escherichia coli to study the feasibility of metabolic exchange between them. Purine is a primary component of cellular metabolism, whereas vitamins are required in catalytic amounts by cells. This differential requirement of metabolites poses the question of whether a synthetic community could arise from the mutual requirement of biosynthetic metabolites. This study attempts to understand the molecular principles that govern the formation of microbial association by understanding the exchange feasibility of molecules of purine and thiamin. We will also endeavor on the circumstances under which a microorganism would interact with another one in a microbial community and whether those two organisms possess the ability to supplement each other’s metabolic requirements. We used auxotrophic strains ∆purM and ∆purK, which are purine biosynthesis mutants, and observed the possibility of exchange of HMP, TMP, and purine biosynthetic intermediates with thiamin biosynthesis mutants ∆thiC, ∆thiE, ∆thiG. Our study presents the basis for understanding purine and thiamin intermediate metabolite sharing among microorganisms and unveils a comprehensive direction for setting up synthetic microbial cocultures.