Isolate Rare Actinomycetes From Entironment Of Torrid Zone, Taxanomy And Bioactivity Screening

In this research, soil samples collected from different environments including mangroves in Qinglan and Dongzai Harbors in Hainan province as well as those in Shenzhen and Zhanjiang; Tropical rain forest of Diaoluo Mountain, rubber tree forest in Danzhou,volcano area in Haikou, etc. Samples were pretreated with dry heating, adding phenol and SDS and then applied to selective media adding with different antibiotics. One hundred and fourteen isolates were selected and primarily classified by their morphology on the agar plates and under microscope. Thirty eight isolates were putatively identified to the genus level based on 16S rDNA sequence analysis and cell wall amino acid analysis by TLC. Neighbor-joining tree based on almost-complete 16S rRNA gene sequences showing the systematic relationship between the 38 strains.The 114 strains were classified to 7 genus of Actinomadura, Actinoplanes, Micromonospora, Streptosporangium, Nocardia, Microtetraspora and Streptoverticillum.Through detection of bioactivities on the 114 rare actinomycetes isolates, 22 strains showed activity against B16 cell, which was 19.3% of total strains; 25 strains were active against Candida albicans, which was 21.9% of total strains. Strains isolated from mangroves showed higher percentage of bioactivity than other envrironment, which was 33.3%.The distributions of rare actinomycetes in different environment in this research were different. In mangroves Micromonospora and Actinoplanes were of predominant genus. More diversity of rare actinomycetes was found in tropical rain forests of Diaoluo mountain, which are Actinomadura, Actinoplanes, Micromonospora, Nocardia, Microtetraspora and Streptoverticillum.