SynCom-mediated microbial community changes in food waste anaerobic digestion Metagenome
We constructed two synthetic microbial consortia (SynComs) using a function-driven strategy: a methanogen-only consortium (SynCom-J) and a multi-stage consortium comprising hydrolytic, acidogenic, and methanogenic members (SynCom-YSJ). Three groups were established based on the microbial seeds added for bioaugmentation: (1) CK (control group, inoculated only with anaerobic digestion liquid inoculum); (2) J (SynCom-J); and (3) YSJ (SynCom-YSJ). Triplicate reactors were conducted for each group. The anaerobic digestion liquid inoculum was loaded into reactors with working volumes of 860 mL. After headspace purging with high-purity nitrogen (99.999%) for 10 minutes, three-day starvation cultivation was initiated to exhaust residual degradable organic matter. Subsequently, SynComs were added to the reactors, and daily feeding using food waste hydrolysate was carried out, with the OLR incrementally increased from 1.5 to 2.2 g-1 VS d-1. All reactors were operated at 37 C under continuous stirring at 110 rpm and a hydraulic retention time (HRT) of 34 days. Metagenomic shotgun sequencing was conducted on 30 samples, including the initial anaerobic digestion liquid inoculum and digestate collected on Days 1, 17, and 34 from three parallel reactors per group. In this study, we aimed to characterize the metabolic implications of SynComs.