1. A membraneless starch/O2 biofuel cell based on bacterial surface regulable displayed sequential enzymes of glucoamylase and glucose dehydrogenase.
- Author
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Cai, Yuanyuan, Wang, Mingyang, Xiao, Xinxin, Liang, Bo, Fan, Shuqin, Zheng, Zongmei, Cosnier, Serge, and Liu, Aihua
- Subjects
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AMYLOLYSIS , *BACTERIAL cell surfaces , *MULTIENZYME complexes , *GLUCOAMYLASE , *LACCASE , *BIOMASS energy , *ENZYMES , *REDOX polymers - Abstract
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 2 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 2 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−2, and good operational stability. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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