Biohydrogen production from Enterobacter cloacae IIT-BT 08 using distillery effluent

•Suitability of distillery effluent for hydrogen production using E. cloacae IIT-BT 08.•Effect of yeast extract, malt extract, Fe, Mg and Cu on hydrogen production.•Interaction among supplements was studied using central composite design (CCD).•Multi-parameter optimization using CCD improved hydrogen yield by 2.2 folds.

Distillery effluent poses severe environmental pollution problem mainly due to its high organic content. During alcohol fermentation, most of the essential macro- and micro-nutrients get utilized. Therefore, supplementation of these nutrients becomes imperative for the improvement of biohydrogen production. In the present study, starch based distillery effluent was used for dark fermentative hydrogen production using Enterobacter cloacae IIT-BT 08. Hence, this study was undertaken to evaluate the effect of supplementation of yeast extract, malt extract, Fe++, Cu++ and Mg++ on biohydrogen production. The interaction among supplements and their mutual effect on the hydrogen production was studied using five factor–five level central composite design). Optimum hydrogen yield of 7.4 mol H2/kg CODreduced was predicted by the model, which showed an excellent correlation with experimental hydrogen yield of 7.38 ± 0.24 mol H2/kg CODreduced. An average hydrogen production rate of 80 mL/L h was achieved after supplementation, having 2.2 times higher hydrogen yield as compared to non-supplemented distillery effluent.