Enzyme Activity and Diversity of a Straw-Degradation Microbial Community

A microbial community could decomposed 55.1% of rice straw in weight within 5 days, among them cellulose content decreased by 63.4% and hemicellulose content decreased by 43.9%. And the content of water soluble carbohydrates (WSC) in the fermentation broth increased progressively during the initially days, and decreased thereafter, suggesting an accumulation of WSC in the early phase of the degradation process. Furthermore the community could excrete cellulases and hemicellulase simultaneously. In order to find out the relation between multienzyme and bacterial composition of the community, the standard enzyme activity assays was used. Results showed that the cellulases and hemicellulase activity were all one trend, that all of them were all ascended expeditiously until reached the peak, after that descended rapidly. In order to determine the bacterial composition of the community, clone library was used to clarified bacterial composition. Constructed 16S rDNA clone library showed 60% closest relative among them were known the detailed information. Some of closest relative of Clostridium and bacteria could excrete cellulase and hemicellulase, which might be the main reason for the community with multienzyme.