Uncovering the metabolic potential of mixed microbial cultures

Microorganisms are an important source of varous chemicals, such as drugs, vitamins, flavors, and biofuels. However, what is currently known about microbial metabolism is limited because most studies on microbial metabolism use axenic culture; that is, a pure culture of a single microbial species. Although axenic culture provides a tractable and reproducible system, its use severely limits our ability to harness the enormous metabolic potential of microorganisms. This is because microbes in nature live in a heterogeneous community, in which various microbes form interdependent metabolic networks to sustain the survival of the community. As such, most microbes in nature cannot be cultivated as an axenic culture in the laboratory, thereby keeping the majority of microbial metabolic activities out of our reach. To gain access to the untapped metabolic potential of microbes, we have been studying mixed microbial cultures (MMCs) that are derived from plants and environmental samples. Here, we present a series of data that demonstrate MMCs can serve as a stable platform to explore their metabolic potential. This presention will highlight our recent discoveries from this MMC program; namely, (1) the discovery of potential signaling factors for interspecies communication, (2) biotransformation of indole derivatives, and (3) biomineralization, a process in which metal ions in aqueous media are transformed into nanoscale particles.