Department of Civil Environmental Engineering, Pusan National University, Busan, Korea.
Water Sci Technol. 2012;66(4):748-53. doi: 10.2166/wst.2012.240.
Microbial fuel cells (MFCs) can convert chemical energy to electricity using microbes as catalysts and a variety of organic wastewaters as substrates. However, electron loss occurs when fermentable substrates are used because fermentation bacteria and methanogens are involved in electron flow from the substrates to electricity. In this study, MFCs using glucose (G-MFC), propionate (P-MFC), butyrate (B-MFC), acetate (A-MFC), and a mix (M-MFC, glucose:propionate:butyrate:acetate = 1:1:1:1) were operated in batch mode. The metabolites and microbial communities were analyzed. The current was the largest electron sink in M-, G-, B-, and A-MFCs; the initial chemical oxygen demands (COD(ini)) involved in current production were 60.1% for M-MFC, 52.7% for G-MFC, 56.1% for B-MFC, and 68.3% for A-MFC. Most of the glucose was converted to propionate (40.6% of COD(ini)) and acetate (21.4% of COD(ini)) through lactate (80.3% of COD(ini)) and butyrate (6.1% of COD(ini)). However, an unknown source (62.0% of COD(ini)) and the current (34.5% of COD(ini)) were the largest and second-largest electron sinks in P-MFC. Methane gas was only detected at levels of more than 10% in G- and M-MFCs, meaning that electrochemically active bacteria (EAB) could out-compete acetoclastic methanogens. The microbial communities were different for fermentable and non-fermentable substrate-fed MFCs. Probably, bacteria related to Lactococcus spp. found in G-MFCs with fermentable substrates would be involved in both fermentation and electricity generation. Acinetobacter-like species, and Rhodobacter-like species detected in all the MFCs would be involved in oxidation of organic compounds and electricity generation.
微生物燃料电池（MFC）可以利用微生物作为催化剂，将各种有机废水作为基质，将化学能转化为电能。然而，当使用可发酵基质时，电子会丢失，因为发酵细菌和产甲烷菌参与了基质到电能的电子流动。在这项研究中，使用葡萄糖（G-MFC）、丙酸盐（P-MFC）、丁酸盐（B-MFC）、乙酸盐（A-MFC）和混合物（M-MFC，葡萄糖：丙酸盐：丁酸盐：乙酸盐=1:1:1:1）以批处理模式运行 MFC。分析了代谢物和微生物群落。电流是 M-、G-、B-和 A-MFC 中最大的电子汇；与电流产生相关的初始化学需氧量（COD(ini)）分别为 M-MFC 为 60.1%、G-MFC 为 52.7%、B-MFC 为 56.1%和 A-MFC 为 68.3%。大多数葡萄糖通过乳酸（COD(ini)的 80.3%）和丁酸盐（COD(ini)的 6.1%）转化为丙酸盐（COD(ini)的 40.6%）和乙酸盐（COD(ini)的 21.4%）。然而，在 P-MFC 中，未知来源（COD(ini)的 62.0%）和电流（COD(ini)的 34.5%）是最大和第二大电子汇。只有在 G-MFC 和 M-MFC 中才检测到超过 10%的甲烷气体，这意味着电化学活性细菌（EAB）可以胜过乙酰化产甲烷菌。可发酵和不可发酵基质喂养的 MFC 的微生物群落不同。可能与可发酵基质的 G-MFC 中发现的乳球菌属相关的细菌将参与发酵和发电。在所有 MFC 中检测到的类似不动杆菌属和类似红杆菌属的物种将参与有机化合物的氧化和发电。
