Cellulase extraction from cellulolytic bacteria promoting bioelectricity production by degrading cellulose

Abstract In this study, mixed culture obtained from waste water was subjected to enzyme extraction which was used with carboxymethyl cellulose (CMC) in microbial fuel cell (MFCs) for electricity generation. Higher current density of the mixed culture enriched on electrode surface in the presence of dialyzed enzyme was 360 μA cm −2 than without enzyme (307 μA cm −2 ). Similarly, power density of MFCs with the dialyzed enzyme (866 ± 16.6 mW m −2 ) was also higher than that without enzyme (737 ± 2.0 mW m −2 ). Sequencing and relative abundance analysis of community diversity in the enriched exoelectrogenic mixed culture biofilms in presence and absence of dialyzed enzyme added system showed Tolumonas as ratio of 50%, being much higher than that in the enriched community without adding enzyme (less than 10%). Among them three strains of n1, n2 and n3 were isolated and evaluated for their cellulase activity with 0.67 IU mL −1  min −1 , 0.46 IU mL −1  min −1 and 0.46 IU mL −1  min −1 , respectively. These results demonstrated that microbial crude enzyme subjected to partial purification had effect on bacteria community diversity composition of the mixed culture enriched on the electrode which improved the electricity generation performance of MFC by hydrolyzing CMC as carbon source.