Mesocosm sludge bioreactors for microbial protein production from soybean processing wastewater, 16S rRNA gene amplicons Metagenome

In this study, single cell protein (SCP) production from soybean processing wastewaters was evaluated, through controlled bioconversion conditions to upcycle nutrients using the microbial communities already present in these wastewaters. Six sequencing batch reactors of 4.5-L working volume were operated for 34 d, in 3 h anaerobic and 9 h aerobic phases at 30 Celsius degrees. Four reactors started without microbial inoculum, while the remaining two started with a 1.5-L inoculum from prior SCP production. Microbial characterization was done via 16S rRNA gene amplicon sequencing. Influent wastewater batches had variable chemical characteristics, but similar microbial composition. We showed that soybean wastewater can be upcycled into SCP through microbial community-based bioconversion, highlighting the effect of variable influent wastewater composition on SCP production.