Research On Community Structure And Function Microorganism Of Anaerobic Cellulose Degradaiton Composite Microbial System

For cellulolytic matters, the heterogeneity of composition and the particularity of structure are theprimary reasons that lead to appearance of the microbial and enzyme attack. For a long time, thehydrolytic process of cellulose remains to be considered as the most essential speed-limiting stage of thebiotransmation. It is started from boosting the degradation speed of cellulose, by screening theanaerobes which belong to efficient degraded cellulose, analyzing the community structure ofcellulolytic microbial system, searching for the synergistic effect among various strains, as well as thefunction in the degradation process, so that it could build stable and efficient anaerobiccellulose-degradation mix cultures, and finally achieve the resoure utilization of cellulose and providescientific theory and practical foundation in the aspect of methodology.The research achievements:1. We adopted Hungate anaerobic technique to isolate strain HCp from horse manure mixed culture.According to the results of morphological, physiological, biochemical and phylogenetic analysis, HCpwas identified as a new species of the genus Acetivibrio. The strain Hcp was thermophilic, efficientlycellulolytic anaerobe with diverse substrate utilizations and high thermostable enzymes. It was apotential bacteria that can be used for cellulosic ethanol producing.2. After subculturing the cellulose-degradation mix culture CBC which was capable of degradingcellulose to methane with high efficiency and making further research of the structure and function ofits stains, we found that the microorganisms belonging to composite microbial system CBC, whosestructure and function remains stable. The bacterial dominate species mainly include: Acetivibrio,Aminobacterium, Alcaligenes, Clostridium, Ruminococcus, Spirochaeta and dominate methanogenicspecies mainly include: Methanobacterium, Methanoculleus, Methanosarcina.3. We did the anaerobic enrichment culture using a variety of samples from the diverseenvironments, after screening (limited cultivation and optimized combination), eventually, we build agroup of anaerobic cellulose-degradation composite microbial system PSW with the high-efficient andculturing-stable quality. In40hours, the filter paper cellulose will be disintegration completely. Thedominant bacteria of PSW is made up by six kinds of microorganism: Acetivibrio, Aminobacterium,Alcaligenes, Bacteroides, Clostridium and Porphyromonadaceae.4. Compaired with the composition of CBC, PSW which got from different samples andconstruction ways, bears highly similarity in the dominant bacteria composition. These structures lay atheory foundation on the future co-cultivating technology and the analysis of the relationship ofsynergistic effect among microorganism.