Open AccessUnravelling biocomplexity of electroactive biofilms for producing hydrogen from biomass
Author(s) -
Lewis Alex J.,
Campa Maria F.,
Hazen Terry C.,
Borole Abhijeet P.
Publication year - 2018
Publication title -
microbial biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.287
H-Index - 74
ISSN - 1751-7915
DOI - 10.1111/1751-7915.12756
Subject(s) - biorefinery , biomass (ecology) , microbial electrolysis cell , biochemical engineering , hydrogen production , biohydrogen , dark fermentation , bioreactor , microbial fuel cell , pulp and paper industry , microbial population biology , environmental science , fermentation , microbiology and biotechnology , biofuel , chemistry , hydrogen , anode , biology , ecology , food science , bacteria , genetics , organic chemistry , electrode , engineering
Summary Leveraging nature's biocomplexity for solving human problems requires better understanding of the syntrophic relationships in engineered microbiomes developed in bioreactor systems. Understanding the interactions between microbial players within the community will be key to enhancing conversion and production rates from biomass streams. Here we investigate a bioelectrochemical system employing an enriched microbial consortium for conversion of a switchgrass‐derived bio‐oil aqueous phase ( BOAP ) into hydrogen via microbial electrolysis ( MEC ). MEC s offer the potential to produce hydrogen in an integrated fashion in biorefinery platforms and as a means of energy storage through decentralized production to supply hydrogen to fuelling stations, as the world strives to move towards cleaner fuels and electricity‐mediated transportation. A unique approach combining differential substrate and redox conditions revealed efficient but rate‐limiting fermentation of the compounds within BOAP by the anode microbial community through a division of labour strategy combined with multiple levels of syntrophy. Despite the fermentation limitation, the adapted abilities of the microbial community resulted in a high hydrogen productivity of 9.35 L per L‐day. Using pure acetic acid as the substrate instead of the biomass‐derived stream resulted in a three‐fold improvement in productivity. This high rate of exoelectrogenesis signifies the potential commercial feasibility of MEC technology for integration in biorefineries.