Cai Yuanyuan, Wang Mingyang, Xiao Xinxin, Liang Bo, Fan Shuqin, Zheng Zongmei, Cosnier Serge, Liu Aihua
Institute for Biosensing, and College of Life Sciences, Qingdao University, Qingdao, 266071, China.
Institute for Biosensing, and College of Life Sciences, Qingdao University, Qingdao, 266071, China; Department of Chemistry, Technical University of Denmark, 2800, Kongens Lyngby, Denmark.
Biosens Bioelectron. 2022 Jul 1;207:114197. doi: 10.1016/j.bios.2022.114197. Epub 2022 Mar 18.
Enzymatic biofuel cells (EBFCs) provide a new strategy to enable direct biomass-to-electricity conversion, posing considerable demand on sequential enzymes. However, artificial blend of multi-enzyme systems often suffer biocatalytic inefficiency due to the rambling mixture of catalytic units. In an attempt to construct a high-performance starch/O EBFC, herein we prepared a starch-oxidizing bioanode based on displaying a sequential enzyme system of glucoamylase (GA) and glucose dehydrogenase (GDH) on E.coli cell surfaces in a precise way using cohesin-dockerin interactions. The enzyme stoichiometry was optimized, with GA&GDH (3:1)-E.coli exhibiting the highest catalytic reaction rate. The bioanode employed polymerized methylene blue (polyMB) to collect electrons from the oxidation of NADH into NAD, which jointly oxidized starch together with co-displayed GA and GDH. The bioanode was oxygen-insensitive, which can be combined with a laccase based biocathode, resulting in a membranless starch/O EBFC in a non-compartmentalized configuration. The optimal EBFC exhibited an open-circuit voltage (OCV) of 0.74 V, a maximum power density of 30.1 ± 2.8 μW cm, and good operational stability.
酶生物燃料电池（EBFCs）为实现生物质直接转化为电能提供了一种新策略，这对顺序作用的酶提出了相当高的要求。然而，多酶系统的人工混合往往由于催化单元的杂乱混合而导致生物催化效率低下。为了构建高性能的淀粉/O酶生物燃料电池，在此我们制备了一种淀粉氧化生物阳极，该阳极基于使用黏连蛋白-对接蛋白相互作用，以精确的方式在大肠杆菌细胞表面展示葡萄糖淀粉酶（GA）和葡萄糖脱氢酶（GDH）的顺序酶系统。优化了酶的化学计量比，GA&GDH（3:1）-大肠杆菌表现出最高的催化反应速率。该生物阳极采用聚合亚甲基蓝（polyMB）从NADH氧化为NAD的过程中收集电子，NADH与共展示的GA和GDH共同氧化淀粉。该生物阳极对氧气不敏感，可与基于漆酶的生物阴极结合，形成非分隔配置的无膜淀粉/O酶生物燃料电池。最优的酶生物燃料电池开路电压（OCV）为0.74 V，最大功率密度为30.1±2.8 μW cm，且具有良好的运行稳定性。
