Construction Of Rumen Bacterial Artificial Chromosome Library And Screening Function Gene From A Goat Rumen Microflora

Most of the microbes present in many environments are not readily culturable which limits the research of microorganism. Metagenome libraries were constructed by directly extracting DNA from environmental sample and transforming to surrogate host and screening novel function genes. In order to study the effect of the degradation of cellulose of a goat rumen microflora, the mixed microbial DNA was extracted from rumen samples of goat. After partial digestion with BamH I, DNA fragments ranging from 50~800kb was collected and ligated to pCC1BAC vector and the ligation mixture was transformed in to E. coli EPI300. After RFLP analysis, the rumen metagenomic BAC library with 12672 clones was constructed and the average insert fragment is about 61 kb. 16 positive clones ofβ-glucosidases were got from the BAC library by using plate of esculin culture medium.Do further study of a higher positive clone, recoveried fragment from 2~5 kb after partial digestion with Sau3A I, and ligated to pUC 19. Obtained positive clone after DNA be transformed into E. coli DH5α. 4566bp fragments obtained after sequence analysis. By comparison of DNA sequences, it is cellulase gene from E.coli genome.