Sunday, July 26, 2009
P5

Degradation of Rice Straw by Bacillus niabensis HCYU-B2 Hemicellulases and Contribution of Scaffolding Protein

Chia-Wen Hsieh, Chia-Chun Lai, Jhong-Jie Cao, and Kuan-Lun Huang. Microbiology and Immunology, National ChiaYi University Taiwan, No. 300, University Rd., ChiaYi, Taiwan

Currently, the worldwide awareness of global climate change, urban air pollution, and security of future supply of energy carriers stimulates research for alternative fuels. Biofuels are an attractive alternative to current petroleum-based fuels as they can be utilized as transportation fuels with little change to current technologies and have significant potential to improve sustainability and reduce greenhouse gas emissions. Liquid (ethanol, biodiesel) or gaseous (methane or hydrogen) biofuels are derived from organic materials such as starch, oilseeds, or cellulose.Cellulose is the most abundant biopolymer in the world. Discarded cellulosic biomass derived from forestry and agriculture are potential feedstocks for the synthesis of biofuels. As the primary and rate-limiting step involved in waste degradation, cellulose breakdown is an important step in the development of strategies to treat cellulosic biomass. Bacillus niabensis HCYU-B2, isolated from a digester produces various extracellular cellulo/xylano-lytic enzymes when induced with various sources of cellulosic materials. B. niabensis HCYU-B2 shows significant xylanolytic and slight cellulolytic activities when induced with brichwood-xylan. There was no detectable cellulo/xylano-lytic activity exhibited during induced with avical, however, scanning electron microscopic analysis revealed the adhesion of cells to avical. Synergistic effects were observed in increments in both simultaneous and sequential reactions with brichwood-xylan induced cellulo/xylano-lytic enzymes and avical induced avical-associated fraction. Based on the degradation of different types of celluloses and hemicelluloses, the interaction between brichwood-xylan induced cellulo/xylano-lytic enzymes and avical induced avical-associated fraction displayed a diversity that suggests that dockerin-cohesin interaction from Bacillus niabensis HCYU-B2 may be existed and more selective than random.