Microbial hydrogen production with Bacillus coagulans IIT-BT S1 isolated from anaerobic sewage sludge

Bacillus coagulans strain IIT-BT S1 isolated from anaerobically digested activated sewage sludge was investigated for its ability to produce H-2 from glucose-based medium under the influence of different environmental parameters. At mid-exponential phase of cell growth, H-2 production initiated and reached maximum production rate in the stationary phase. The maximal H-2 yield (2.28 mol H-2/mol glucose) was recorded at an initial glucose concentration of 2% (w/v), pH 6.5, temperature 37 degrees C, inoculum volume of 10% (v/v) and inoculum age of 14 h. Cell growth rate and rate of hydrogen production decreased when glucose concentration was elevated above 2% w/v, indicating substrate inhibition. The ability of the organism to utilize various carbon sources for H-2 fermentation was also determined. (c) 2006 Elsevier Ltd. All rights reserved.