Abstract: Homoacetogenesis is an important pathway for $ CO_{2} $ bio-utilization, but the process is interfered by $ O_{2} $. This study investigated the effects of different temperatures on the efficiency of homoacetogenesis, methanogenic and acetic acid-producing activities, INT-ETS and coenzyme $ F_{420} $ activities, and the microbiological community structure under anaerobic and aerobic conditions. The results showed that no HAc was produced under aerobic conditions at $ 35\;^{\circ}C $, but at $ 15\;^{\circ}C $, the cumulative HAc production of homoacetogenesis was $ (174.8\pm0.4)\;\mathrm{mg/g} $ under aerobic conditions; on the contrary, the cumulative $ CH_{4} $ production decreased by 82.0%, from $ (198.1\pm9.7)\;\mathrm{mL/g} $ at $ 35\;^{\circ}C $ to $ (35.6\pm9.3)\;\mathrm{mL/g} $ at $ 15\;^{\circ}C $. Low-temperature conditions not only inhibited the activities of INT-ETS and coenzyme $ F_{420} $, but also enriched the typical homoacetogens Acetobacterium. Therefore, the low-temperature control during homoacetogenesis under aerobic conditions not only helped to inhibit the methanogenesis, but also increased the cumulative yield of HAc.
Keywords: homoacetogenesis; carbon dioxide; acetic acid; methane; hydrogenotrophic methanogen
合肥工业大学学报自科版