Microbiome analysis of MFCs Exp5

Microbial fuel cells (MFCs) can generate electricity simultaneously with wastewater treatment. For MFCs to be considered as a cost effective treatment technology, it should quickly re-establish a stable electro-active microbial community in case of system failure. In order to shorten startup times, temporal studies of anodic-biofilm development are required, however, frequent sampling may reduce functionality of the system due to electroactive-biomass loss; therefore, on-line monitoring of the microbial community without interfering with the system's stability is essential. Athough all anodic-biofilms were composed of Desulfuromonadaceae, MFCs differed in startup times. Generally, a Desulfuromonadaceae-dominated-biofilm was associated with faster startup-MFCs. A positive PCR product of a specific 16S rRNA gene PCR primer set for detecting the acetate-oxidizing, PCE-dechlorinating Desulfuromonas group was associated with efficient-MFCs in our samples. This observation could therefore serve as a biomarker for monitoring the formation of an efficient anodic biofilm. Additionally, we successfully enriched an electroactive consortium from an active anode also resulting in a positive amplification of the specific primer set. Direct application of this enrichment to a clean MFC anode showed a substantial reduction of startup times from 16 to 3 days.