Mixed culture fermentation for production of medium-chain carboxylates (MCC) Targeted loci environmental

To identify the key microorganisms responsible for MCC production during the fermentation of complex organic substrates supplemented with H2 and CO2, two bioreactors were established and initially supplied with the brewer's spent grain as the organic feedstock. Inorganic substrates, H2 and CO2, were added daily throughout the 63-day fermentation period. Time-course analyses of net metabolite production rates, alongside microbial community profiling via 16S rRNA amplicon sequencing, revealed Megasphaera elsdenii and Megasphaera hexanoica as the primary chain-elongating organisms in the system.