Research Of Constructing Metagenomic Library And Diversity Of Black Goat Gastrointestinal Tract

China is a country with resources.however, agriculture wastes,straw and other wastes abandent of cellulose are increasing at the same time.how to improve the comprehensive utilization of these resources are becoming one hotspot of research.There are a lot of microbes of decomposing cellulose in nature biosphere,and over99%of them can not be cultured by traditional methods,while they contain abundant of gene resources.and therefore.a new way to screen cellulase is available by constructing metagenomic library and screening cellulase gene.In this research,PFGE technology was used to construct a rumen uncultured microorganisms metagenomic library of black goat,from which we screened cellulose clones.Besides,diversity of microbial community structures in different part of black goat gastrointestinal tract are both analyzed.and the results are as follows:(1) Extract purified DNA with the way of low metling agarose embedding and digest them to100-200kb each by Hind Ⅲ,and then constructed microbial metagenomic library by BAC vector.The library contained5000clones, from which we could screen two clones with endoglucanase and β-glucuroide activity, named as B112-C12and B112-D12.(2) Amplified the microbes(bacteria and fungi) gene fragments in different parts of black goat gastrointestinal tract by PCR technique firstly and then isolated them by DGGE technique,we got a result,the similarity of bacteria and fungi microbes'diversity of microbial community structure in the colon and cecum partsbacterial of black goat was high,84%and74%respectively.Furthermore,after analyzed the microbial Shannon-Weiner index and PieLou index of black goat gastrointestinal tract, we found that the diversity of colon bacteria index was the highest(H'=4.4609), meanwhile, the PieLou index of the rest sample is high,excluding the low result in stomach-1and stomach-2;however,the Shannon-Weiner index of stomach-1was high and the PieLou index of nine samples were also high,there was no obvious difference. In this research, the microorganisms BAC metagenomic library was constructed.and the diversity of microbial community structure was analyzed,which provided reference for further research in metagenomics and micro-ecology.