Abstract
Electrochemically active bacteria (EAB) receive considerable attention in sustainable biotechnology, since they are essential components in microbial fuel cells (MFCs) that are able to generate electricity from biomass wastes. EAB are also expected to be applied to the production of valued chemicals in microbial electrosynthesis systems (MESs) with the supply of electric energy from electrodes. It is, therefore, important to deepen our understanding of EAB in terms of their physiology, genetics and genomics. Knowledge obtained in these studies will facilitate the engineering of EAB for developing more efficient biotechnology processes. In this article, we summarize current knowledge on Shewanella oneidensis MR-1, a representative EAB extensively studied in the laboratory. Studies have shown that catabolic activities of S. oneidensis MR-1 are well tuned for efficiently conserving energy under varied growth conditions, e.g., different electrode potentials, which would, however, in some cases, hamper its application to biotechnology processes. We suggest that understanding of molecular mechanisms underlying environmental sensing and catabolic regulation in EAB facilitates their biotechnological applications.
Highlights
Active bacteria (EAB) are capable of electric interactions with extracellularly located redoxactive materials, such as electrodes (Chang et al 2006; Sydow et al 2014)
Successful laboratory examples have been reported, production efficiencies reported in these studies are much lower than those reported for conventional fermentation processes (Kracke et al 2018)
This would be attributable to the facts that MR-1 was isolated from lake sediment, and its metabolic pathways are well tuned for surviving in nutrient-limited natural environments (Hirose et al 2018)
Summary
Active bacteria (EAB) are capable of electric interactions with extracellularly located redoxactive materials, such as electrodes (Chang et al 2006; Sydow et al 2014) Owing to their abilities to catalyze various intracellular catabolic reactions with the aid of electrodes, EAB serves as essential components in bioelectrochemical systems (BESs), including microbial fuel cells (MFCs) and microbial electrosynthesis systems (MESs) (Schröder et al 2015). Many EAB have been isolated and characterized in the laboratory (Doyle and Marsili 2015; Kokko et al 2016; Ueoka et al 2018), our knowledge on molecular mechanisms underlying electrochemical interactions of EAB with electrodes has mostly been gained in studies using model EAB, including Shewanella oneidensis MR-1 and Geobacter sulfurreducens PCA (Sydow et al 2014) These bacteria were originally isolated as dissimilatory metal-reducing bacteria that can respire using. Comparative evaluation of activities of different EAB in same BESs is limited (Newton et al 2009; Kato et al 2013)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
