Dual-chamber differs from single-chamber microbial electrosynthesis in biogas production performance under low temperature (15℃)

• DOI: 10.1016/j.biortech.2021.125377
• Publication Date: 2021-06-03T03:53:44Z
• Authors: Hui Wang; Hongxia Du; Haiyin Xie; Jiemin Zhu; Shufang Zeng; Yasuo Igarashi; Feng Luo
• Keywords: Biofuels; Temperature; 0202 electrical engineering, electronic engineering, information engineering; Methanosarcinaceae; 02 engineering and technology; Carbon Dioxide; Electrodes; Methane; 7. Clean energy; 6. Clean water

In this study, single-chamber and dual-chamber Microbial electrosynthesis (MES) with carbon fiber brushes as electrodes were operated at 15°C to compare and analyze the difference in methanogenic performance. Metatranscriptomic analysis showed that the relative abundance of electroactive microorganisms Syntrophomonas, Pseudomonas and Bacteroides in each group exceeded 90%, while the abundance of Geobacter was less than 4%. Acetoclastic methanogens Methahnosarcina was more enriched in dual-chamber MES (61.74%~70.42%), and Methanothrix showed higher abundance in single-chamber MES (33.44%~51.71%). Methahnosarcina and Methanothrix could interact with electroactive microorganisms to improve the electron transfer efficiency through direct interspecies electron transfer (DIET). Analysis of the methane metabolic pathways of low-temperature MES found acetoclastic pathway was domination, and single-chamber MES achieved acetate to acetyl-CoA through acetate-CoA ligase (EC: 6.2.1.1), whereas dual-chamber MES was by acetate kinase (EC: 2.7.2.1) and phosphate acetyltransferase (EC: 2.3.1.8). These results are beneficial to further research on the treatment of low-temperature wastewater.