Comparative metabolomic studies of Alkanivorax xenomutans showing differential power output in a three chambered microbial fuel cell

Abstract

Metabolomic study of electrogenic bacteria is a necessity to understand the extent of complex organic matter degradation and to invent new co-culture techniques to achieve complete degradation. In this study, we have subjected Alkanivorax xenomutans (KCTC 23751T; NBRC 108843T), a bacterium capable for biodegradation of complex hydrocarbons, to oxic and anoxic conditions in a three chambered microbial fuel cell. In an attempt to understand the molecular mechanisms during the electrogenic processes of A. xenomutans, intra cellular (endo metabolome or the fingerprint) and exo metabolome (extracellular metabolome or the foot print) were analyzed under oxic and anoxic conditions, using FTIR and GC–MS. Interpretation of the data revealed higher number of metabolites in the anoxic fraction as compared to oxic fraction. In addition, expression of putative metabolites that influence electron transfer like flavins, fumarate and quinones were found to be predominant in the organisms when grown in anoxic conditions. Hence, the presence of anoxic conditions governed the electrogenic bacteria to produce enhanced power output by modulating differential metabolomic profiling, compared to the culture grown in oxic conditions.