Abstract:

Soil samples were collected from Maotai town and periphery areas in Chishui river basin. A total of 32 actinomycetes were isolated from 6 soil samples with Gaos No.1 synthetic medium. Molecular identification and phylogenetic analysis were carried out on 15 isolates selected by morphology and biochemistry characteristics. The results of 16S rDNA sequencing and comparison with the reported data in GenBank revealed that strain MA06 is Nocardioides albus, MA24 is genus of Promicromonospora, and the other 13 isolates are genera of Streptomyces, among which MA03 is Streptomyces fulvissimus, MA14 is Streptomyces europaeiscabiei and MA07 is Streptomyces sp.. Phylogenetic analysis indicated that MA06 and MA24 clustered in 2 branches individually, and the other 13 isolates clustered together, forming the third branch. These facts proved that the distance between these 3 genera of Nocardioides, Promicromonospora and Streptomyces is far off. The antimicrobial efficacy of strains M07, M25, M30 and M32 is powerful by bacteria and fungi test. The results indicated the potential of these isolates may serve as biocontrol or antibiotics producing microbes.

Key words: Chishui river basin, actinomycetes from soils, 16S rDNA, phylogenetic analysis, antimicrobial activity

摘要：

从贵州赤水河流域茅台镇及周边地区采集土样，用高氏1号培养基从6份土样中共分离到放线菌32株，根据形态学和生理生化特征，从中筛选15株进行分子鉴定和系统发育树分析，16S rDNA测序比对结果表明：MA06为白色类诺卡氏菌(Nocardioides albus)，MA24为原小单孢菌(Promicromonospora)，其余13株为链霉菌(Streptomyces)，其中MA03为极暗黄链霉菌(Streptomyces fulvissimus)，MA14为Streptomyces europaeiscabiei，MA07属Streptomyces sp.。通过构建系统发育树发现：15株放线菌分离株聚为三支，MA06和MA24各单列一支，其余的聚为第三大支，进一步表明了链霉菌属、类诺卡氏菌属和原小单孢菌属相互之间亲缘关系较远。抗菌活性检测发现M07、M25、M30和M32抗菌作用强，预示其作为生防资源菌和抗生素产生菌的潜在价值。

关键词: 赤水河流域;土壤放线菌;16S rDNA;系统发育分析;抗菌活性