Polyphasic Taxonomy Of The Active Actinomycetes

Polyphasic taxonomy studies were carried out on thirteen actinomycetes strains, which have herbicidal activities and isolated from different areas of Yunnan Province. China.In the summarization, the article firstly reviewed on the importance of Actinomycetes as microbial resource. Then it listed some kinds of herbicides produced by microbe, especially by actinomycetes, and summarized the developments and trends of microbial herbicides. Last, the article introduced the technologies and methods of polyphasic taxonomy of Actinomycetes, including the application of the new phylogenetic markers and molecular taxonomic technology.The first part of this study is polyphasic taxonomy analysis of the thirteen strains which have herbicidal activities. The polyphasic taxonomy methods include morphology, cytochemistry, DNA G+C mol%, phylogenetic analysis of 16S rDNA sequences and physiological and biochemical experiments. The results of chemotaxoriomy showed: thirteen strains were divided into five groups, the cell-wall type varied from I/C type to III/B type, contained all the phospholipids type and major menaquinones are different.Based on the nearly all sequence of 16S rDNA of the thirteen strains, they were also divided into five groups: seven strains such as 40001 have similar relationships with the strains of Streptomyces, strain 40009 is similar to Nocardiopsis dassonvillei subsp. Albirubida and their sequence similarity is 100%, strain 40010 and 40011 are similar to the strains of Micromonospora, strain 40012 is similar to Streptosporangium amethystogenes and their sequence similarity is 99.37%, strain 40007 and strain 40008 have a lower sequence similarity with the strains of Actinomadura, which is only 95.43%. So two of them maybe belong to a new genus.According to the results of polyphasic taxonomy, the phylogenetic relationship of thirteen strains were defied that seven strains such as 40001 belong to Streptomyces, strain 40009 belong to Nocardiopsis, strain 40010 and 40011 belong to Micromonospora , strain 40012 belong to Streptosporangium; strain 40007 and 40008 have similar relationship withActinomadura, but their sequence similarity are lower than 97%, may belong to a new genus.The second part of this study is herbicidal activity analysis of some strains. From thebroth of the strains, some yellow crystals were obtained. The chromatographic profiles presented that these crystals all contained several compositions and each of them has the selectively herbicidal activity to the weed, which belonging to dicotyledonous weeds. Moreover, it didn't do harm to the tomato, the dicotyledonous plant.The third part of this study is analysis of 16S-23S rDNA ITS. Specific primers were used and DNA segments of 500bp and part sequence were obtained.