Open AccessA three-dimensional hybrid electrode with electroactive microbes for efficient electrogenesis and chemical synthesis
Author(s) -
Xin Fang,
Shafeer Kalathil,
Giorgio Divitini,
Qian Wang,
Erwin Reisner
Publication year - 2020
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.1913463117
Subject(s) - geobacter , electrode , graphene , indium tin oxide , electrochemistry , chemistry , geobacter sulfurreducens , nanotechnology , bacteria , materials science , biology , biofilm , genetics
Integration of electroactive bacteria into electrodes combines strengths of intracellular biochemistry with electrochemistry for energy conversion and chemical synthesis. However, such biohybrid systems are often plagued with suboptimal electrodes, which limits the incorporation and productivity of the bacterial colony. Here, we show that an inverse opal-indium tin oxide electrode hosts a large population of current-producing Geobacter and attains a current density of 3 mA cm -2 stemming from bacterial respiration. Differential gene expression analysis revealed Geobacter 's transcriptional regulations to express more electron-relaying proteins when interfaced with electrodes. The electrode also allows coculturing with Shewanella for syntrophic electrogenesis, which grants the system additional flexibility in converting electron donors. The biohybrid electrode containing Geobacter can also catalyze the reduction of soluble fumarate and heterogenous graphene oxide, with electrons from an external power source or an irradiated photoanode. This biohybrid electrode represents a platform to employ live cells for sustainable power generation and biosynthesis.