Bioaugmentation with marine sediment-derived microbial consortia in mesophilic anaerobic digestion for enhancing methane production under ammonium or salinity stress

• DOI: 10.1016/j.biortech.2023.128853
• Publication Date: 2023-03-09T07:57:40Z
• Authors: Luong Van Duc; Shintaro Nagao; Mohammad Mojarrad; Yuta Miyagawa; Zi-Yan Li; Daisuke Inoue; Takahisa Tajima; Michihiko Ike
• Keywords: Bioaugmentation; Biostimulation; Mesophile; Microbial consortium; Methanosaeta

Ammonium (NH4+) and salinity (NaCl) inhibit CH4 production in anaerobic digestion. However, whether bioaugmentation using marine sediment-derived microbial consortia can relieve the inhibitory effects of NH4+ and NaCl stresses on CH4 production remains unclear. Thus, this study evaluated the effectiveness of bioaugmentation using marine sediment-derived microbial consortia in alleviating the inhibition of CH4 production under NH4+ or NaCl stress and elucidated the underlying mechanisms. Batch anaerobic digestion experiments under 5 gNH4-N/L or 30 g/L NaCl were performed with or without augmentation using two marine sediment-derived microbial consortia pre-acclimated to high NH4+ and NaCl. Compared with non-bioaugmentation, bioaugmentation reinforced CH4 production. Network analysis revealed the joint effects of microbial connections by Methanoculleus, which promoted the efficient consumption of propionate accumulated under NH4+ and NaCl stresses. In conclusion, bioaugmentation with pre-acclimated marine sediment-derived microbial consortia can mitigate the inhibition under NH4+ or NaCl stress and enhance CH4 production in anaerobic digestion.