Optimization of Fermentative Hydrogen Production by Klebsiella pneumoniae KTSMBNL 11 Isolated from Municipal Sewage Sludge

Abstract

In the present study, the fermentative hydrogen-producing bacterial strain KTSMBNL 11 was isolated from municipal sewage sludge and identified as Klebsiella pneumoniae based on 16S rDNA gene sequence analysis. Batch experimental studies were performed to determine the effects of initial pH, temperature and substrate concentration on hydrogen production. At pH 6.0 and 36 °C, the maximum hydrogen production rate of 525 ml/l/h was obtained with 30 g/l of glucose, and the highest yield of 2.57 mol/mol G was achieved with an initial glucose concentration of 5 g/l. During anaerobic fermentation, the main soluble metabolites obtained were 2, 3-butanediol and ethanol. Under these optimal conditions, Klebsiella pneumoniae has a higher hydrogen yield compared with other pure bacterial cultures reported in the literature. Thus, Klebsiella pneumoniae is a promising option as an effective hydrogen-producer.