Fermentation of simple and complex substrates to biohydrogen using pure Bacillus cereus RTUA and RTUB strains

Abstract

Abstract The microbial conversion of biomass into hydrogen is promising route for clean and renewable bioenergy source. This study focuses on employment of endogenous microbial cultures, for hydrogen production from biomass. Two hydrogen producing strains RTUA and RTUB, isolated from anaerobic digester fed with biomass, were identified as Bacillus cereus based upon 16sRNA analysis and physiochemical characterization. Both strains exhibited wide range of hydrolytic enzymes depending upon substrate provided. This research evaluates biohydrogen potential of RTUA and RTUB from different substrates ranging from simple sugars (glucose, xylose) to complex substrates (rotten fruits, vegetables and wheat straw). Bacillus strains RTUA produced a maximum of 1.15 and 1.05 mol/mole H 2 yield from glucose and xylose. In the BioH2 fermentation of pre-treated and untreated wheat straw, rotten fruits and rotten vegetables, the cumulative H 2 production was higher from the NaOH pretreated wheat straw i.e. 156.4 mL/gVS comparable 40–78 mL/gVS from rotten vegetables and rotten fruits. Owing to diverse hydrolytic enzyme profile and high H 2 yield from complex substrates, RTUA and RTUB proved to be potential candidates for BioH2 production from biomass. The study demonstrated an effective privilege of pure culture for biohydrogen production from mixture of waste biomass and will help to establish eco-friendly and economical setup for biohydrogen production.