Yang Jisu, Sim Young-Bo, Moon Kim Saint, Joo Hwan-Hong, Jung Ju-Hyeong, Kim Sang-Hyoun
Department of Civil and Environmental Engineering, Yonsei University, Seoul 03722, Republic of Korea.
Department of Environmental Engineering, Kunsan National University, Gunsan 54150, Republic of Korea.
Bioresour Technol. 2023 Jun;377:128900. doi: 10.1016/j.biortech.2023.128900. Epub 2023 Mar 17.
The present study investigated the effect of a conductive biofilm supporter on continuous production of biohydrogen in a dynamic membrane bioreactor (DMBR). Two lab-scale DMBRs were operated: one with a nonconductive polyester mesh (DMBR I) and the other with a conductive stainless-steel mesh (DMBR II). The highest average hydrogen productivity and the yield were 16.8% greater in DMBR II than in DMBR I, with values of 51.64 ± 0.66 L/L-d and 2.01 ± 0.03 mol H/mol hexose, respectively. The improved hydrogen production was concurrent with a higher NADH/NAD ratio and a lower ORP (Oxidation-reduction potential). Metabolic flux analysis implied that the conductive supporter promoted H-producing acetogenesis and repressed competitive NADH-consuming pathways, such as homoacetogenesis and lactate production. Microbial community analysis revealed that electroactive Clostridium sp. were the dominant H producers in DMBR II. Conclusively, conductive meshes may be useful as biofilm supporters of dynamic membranes during H production for selectively enhancing H-producing pathways.
本研究调查了导电生物膜载体对动态膜生物反应器（DMBR）中生物制氢连续生产的影响。运行了两个实验室规模的DMBR：一个使用非导电聚酯网（DMBR I），另一个使用导电不锈钢网（DMBR II）。DMBR II的最高平均氢气产率和产量分别比DMBR I高16.8%，其值分别为51.64±0.66 L/L-d和2.01±0.03 mol H/mol己糖。氢气产量的提高与较高的NADH/NAD比率和较低的氧化还原电位（ORP）同时出现。代谢通量分析表明，导电载体促进了产氢乙酰化作用，并抑制了竞争性的消耗NADH的途径，如同型乙酰化作用和乳酸生成。微生物群落分析表明，电活性梭菌属是DMBR II中主要的产氢菌。总之，在制氢过程中，导电网作为动态膜的生物膜载体，可能有助于选择性地增强产氢途径。
