低温强化有氧条件下二氧化碳同型产乙酸研究

同型产乙酸是 $ CO_{2} $ 生物利用的重要途径，但该过程会受到 $ O_{2} $ 组分的干扰。文章探讨不同温度对无氧条件和有氧条件下 $ CO_{2} $ 同型产乙酸效率、污泥产甲烷和产乙酸活性、电子传递活性和辅酶 $ F_{420} $ 活性及其微生物群落结构的影响。结果表明：在 $ 35^{\circ}C $ 有氧条件下未产生乙酸，但在 $ 15^{\circ}C $ 有氧条件下，同型产乙酸的累积乙酸产量为 $ (174.8 \pm 0.4) $ mg/g；相反，在 $ 15^{\circ}C $ 有氧条件下累积甲烷产量下降了 82.0%，由 $ 35^{\circ}C $ 的 $ (198.1 \pm 9.7) $ mL/g 下降为 $ 15^{\circ}C $ 的 $ (35.6 \pm 9.3) $ mL/g。低温条件不仅能抑制电子传递活性和辅酶 $ F_{420} $ 的活性，而且可以富集同型产乙酸菌 Acetobacterium。因此，在有氧条件下二氧化碳同型产乙酸过程中，控制低温不仅有助于抑制甲烷生成，而且能够提高乙酸累积产量。

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.