Methanobacterium enables high rate electricity-driven autotrophic sulfate reduction

Abstract

The autotrophic reduction of sulfate can be sustained with a cathode as the only electron donor in bioelectrochemical systems (BES). This work studies the effect of inoculum source on autotrophic sulfate reduction start-up and performance of autotrophic sulfide production rates using a biocathode in a fed-batch operation mode. After 180 days, low electron and sulfate consumption was observed using BES controlled at -0.9 V vs. SHE and inoculated with mixed microbial consortia from sewer biofilm reactors, anaerobic sludge and mangrove sediments. However, when an enriched electroactive consortium capable of cathodic CO2 reduction to acetate was used as biocatalyst in combination with the above ..