What is the Role of Individual Species within Bidirectional Electroactive Microbial Biofilms: A Case Study on <i>Desulfarculus baarsii</i> and <i>Desulfurivibrio alkaliphilus</i>

Abstract Desulfarculus baarsii and Desulfurivibrio alkaliphilus are strictly anaerobic bacteria existing in marine sediments. D. gains energy through reducing sulphate is able to reduce elemental sulphur, thiosulphate polysulphide seawater. Both organisms were previously identified as key sediment derived, bidirectional electroactive biofilms. Here, we investigated the electrochemical performance of these two bio‐electrochemical systems their possible involvement anodic cathodic reactions. The results show that was unable donate or accept electrons to/from an electrode, while catalyse both reactions interact with electrode direct potentially indirect electron transfer. Raman spectra biofilms showed a high similarity Geobacter sulfurreducens biofilms, including specific bands cytochromes b c, explaining electroactivity bioelectrochemical