Tuesday, May 3, 2011
Two thermophilic, anaerobic bacteria named JN4 and GD17 were isolated from rotten wheat straw. The cellulolytic bacterium JN4 was identified as Clostridium thermocellum and its companion bacterium GD17 was shown to be Thermoanaerobacterium thermosaccharolyticum by 16S rDNA analysis and morphological observation. It was investigated on hydrogen and ethanol production from lignocellulosic biomass with two thermophilic bacteria by co-culture anaerobic fermentation at 60oC.
C. thermocellum JN4 can degrade microcrystalline cellulose to produce hydrogen and ethanol, but cellobiose and glucose released from cellulose were remained. When C. thermocellum JN4 was co-cultured with T. thermosaccharolyticum GD17, hydrogen production increased about 2-fold. Butyrate was the most abundant byproduct at the end of the co-culture process. In co-cultures, JN4 or/and GD17 could utilize lignocellulosic biomass for producing hydrogen.