Phylogenetic Analysis Of Twelve Actinomycete Strains

Phylogenetic analysis was carried out on twelve actinomycetes strains isolated from different areas of Chengde, Baoding and Yunnan Province, China.In summarize, this thesis firstly reviewed the value of actinomycetes as microbial resource on research and using. Then it introduced the developments and trends of taxonomy of actinomycetes. Meanwhile, the new phylogenetic markers and molecular taxonomic technology applied in actinomycete taxonomy have been presented.Firstly, morphology, physiological and biochemical features of the 12 test strains were determined. In the morphologic study, the characters of 12 strains on four culture media were observed by using coverslip techniques. In the physiology and biochemistry experiment, carbon utility, nitric acid deoxidiation, amylum hydrolyzation, antibiotic sensitivity, glutin-liquefication, and NaCl tolerance were studied.DNA G+C mol% of 12 strains varied from 70.74% to 75.22%, which is consistent with actinomyces.Based on the nearly complete sequences of 16S rDNA, the 12 strains could be divided into four groups. Strain 79064 is similar to Nocardiopsis synnemataformans and their 16S rDNA sequence similarity is 98.51%. Strain 84169 has a lower 16S rDNA sequence similarity with the strains of Micromonospora, which is only 94.22%. Strain 87063 has a lower 16S rDNA sequence similarity with the strains of Actinoplanes, which is only 96.45%. Nine strains such as 71413 have similar relationships with the strains of Streptomyces, strain 71413 is similar to Streptomyces ciscaucasicus and their 16S rDNA sequence similarity is 99.77%, Streptomyces ciscaucasicus and Streptomyces canus strain are similar to the strains 84717, their 16S rDNA sequence similarity is 97.52%, strain 81113 is similar to Streptomyces longisporoflavus and their 16S rDNA sequence similarity is 98.84%, strain AH-31-13 is similar to Streptomyces werraensis and their 16S rDNA sequence similarity is 97.99%, Streptomyces xantholiticus and Streptomyces graminofaciens are similar to the strains 78524, their 16S rDNA sequence similarity is 99.00%, strain 83957 is similar to Streptomyces tauricus and their 16S rDNA sequence similarity is 97.26%, strain 84254 is similar to Streptomyces albolongus and their 16S rDNA sequence similarity is 97.52%, strain 74842 is similar to Streptomyces tauricus and their 16S rDNA sequence similarity is 97.05%.According to the results of polyphasic taxonomy, the phylogenetic relationship of 12 strains was defined. Strain 79064 belongs to Nocardiopsis. Nine strains such as 71413,84016, 84717,81113, AH-31-13,78524,83957,84254 and 74842 belong to Streptomyces.Strain 84169 has similar relationship with Micromonospora, but 16S rDNA sequence similarity with the strains of Micromonospora, which is below 95.00%, so it maybe belongs to a new genus. Strain 87063 has similar relationship with Actinoplanes, but 16S rDNA sequence similarity with the strains of Actinoplanes, which is below 97.00%, so it maybe belongs to a new species. Thus, further analysis is needed.