Systematic Study Of The Antagonistic Microbial Resources Of Tianmu Mountain Natural Reserve

Soil samples were collected from 10 different routes in Tianmu Mountain Natural Reserve, and 20 of them were studied for microbe diversity. 145 mildews and 65 bacteria were isolated. All bacterial stains were directed selected with the standard whether there were polyketide synthases I (PKS I ) or nonribosomal peptide synthetases (NRPS) genes in there genomes. The selected stains were tested for antimicrobial activities. There phylogenetic relationships were obtained with sequences analysis of 16S rDNA, gyrA and gyrB. Eighteen strains with PKS I or NRPS genes in there genomes were selected, and eight of them have inhibitory activities towards test stains. All eighteen strains were identified to genus level, and ten of them were identified to species, another three have some differences with those stains in public database, and they may have not been studied or identified. B27 which have remarkable resistant activities was studied further, and the phenotype, cultivation situation, physiological and biochemical characteristics, and phylogenesis was tested in detail.On the basis of these results, B27 was identified as a member of genus Paenibacillus. However, there are differences between B27 and other Paenibacillus stains in 16S rDNA sequences and physiological and biochemical characteristics, thus B27 was considered as a new strain of genus Paenibacillus. Its partial NRPS gene sequence indicated that its antimicrobial products might be cyclo-lipopeptide. All there results showed that Tianmu Mountain Natural Reserve has a great storage of microbe resources. Directed selection with PKS I and NRPS genes as the marker, which is followed with fast identification on molecular level, is a effective way of isolation. Ultimately, several valuable stains were picked out, the stain B27 is a good example.