[Study on biodiversity of type I & II polyketide synthesis genes positive microorganisms]

Abstract

Some soil samples were collected from different places in Yunnan Provinces, China. 876 bacteria or actinomycete strains were isolated using Glucose-Peptone-Yeast extract agar, Starch-Casein agar and Glycerol-Asparagine agar with these soil samples, of which about 100 strains belong to genus Streptomyces and the others belong to rare actinomycetes or bacteria. With polyketide synthesis gene screening, 75 strains were picked up as type I & II polyketide synthesis gene positive strains. Then 10 strains were chosen for 16S rDNA amplification and systematic analysis based on comparing results with their anti-bacteria activity, morphology, and physiological characteristics analysis. They were classified to be at least 7 families and 8 genera, such as genus Streptomyces of the family Streptomycetaceae, two genera Streptosporangium and Nonomuraea of the family Streptosporangiaceae, genus Mycobacterium of the family Mycobacteriaceae, genus Nocardia of the family Nocardiaceae, genus Achromobacter of the family, another two strains belong to the suborder Micrococcineae and the family Oxalobacteraceae', respectively. Eight of them were classified into six potential novel species and two new genera with polyphasic taxonomic methods. The results showed that designing new strategies for isolation and identification of microorganisms from natural environments was the key step to exploit microbial resources.