Increased biofilm in Shewanella oneidensis MR-1 leads to higher current generation in METs

Biofilm formation is a central process in the function of Microbial Electrochemical Technologies (METs). These technologies have emerged in recent years as a promising alternative green source of energy, in which microbes consume organic matter to produce energy or valuable by-products. It is the ability of performing extracellular electron transfer that allows these microbes, called electroactive organisms, to exchange electrons with an electrode in these systems. The low levels of current achieved have been the set-back for the large-scale application of METs. Shewanella oneidensis MR-1 is one of the most studied electroactive organisms, and it has been demonstrated that its increased biofilm formation can lead to higher current generation. The bolA gene has been identified as a central player in biofilm formation in different organisms, with its overexpression leading to increased biofilm production. In this work, we explored the effect of this gene in biofilm formation and current production by S. oneidensis MR-1. Our results demonstrate that this gene is involved in the biofilm formation by this organism, with its over expression leading to an increased biofilm formation. We could also show that this increase in biofilm formation lead to a consequent higher current generation. This information is a relevant step for the optimization of electroactive organisms towards their practical application in METs.