[Characteristics and diversity of a microbial community decomposing wheat straw under aerobic conditions]

A microbial community with the stable ability of effectively decomposing wheat stalks was constructed at room temperature under aerobic conditions by the method of restricted cultivation. The degradation ability of the microbial community shows that when performed in 100 mL improved CMC liquid medium, the depth and diamerer of the fluid level were 2 cm and 9 cm, it kept higher degradation efficiency with capability of decomposing straws of 66.1% during the initial six days. By the tenth day of decomposition, the degradation ratio was slowly up to 77.0%. Analysis of the components of wheat stalk (1.86 g) showed that the cellulose lost 0.78 g, hemicellulose lost 0.16 g and lignin lost 0.24 g. The composition diversity of the microbial community shows that 13 genera of microorganisms were identified by the technologies of clone library and isolation of pure strain. The results indicated that the dominate genera were Hydrogenophaga, Pseudomonas, Bacteroides and Clostridium taking up 78% in one hundred of positive clones. Phylogenetic dendrogram indicates that the relations among clones and isolated strains and their closest relatives presented certain distances; both Isolated 7 (FJ439527) and Clone 86 (EU834839) were closely related to Pseudomonas xiamenensis.