Diversity of Culturable Thermophilic Actinobacteria in Hot Springs in Tengchong, China and Studies of their Biosynthetic Gene Profiles
Diversity of Culturable Thermophilic Actinobacteria in Hot Springs in Tengchong, China and Studies of their Biosynthetic Gene Profiles
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腾冲温泉可培养嗜热放线菌多样性及其生物合成基因谱研究
DOI：
10.1007/s00248-016-0756-2
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发表时间：
2016-07-01
影响因子：
3.6
通讯作者：
Li, Wen-Jun
中科院分区：
文献类型：
--
作者：
Liu, Lan;Salam, Nimaichand;Li, Wen-Jun
放线菌纲一直是发现抗生素的金矿，并引起了学术界和工业界的兴趣。然而，在过去的几十年中，缺乏新的方法限制了对工业有用的新的微生物天然产物的发现。科学家们现在正专注于不同环境的生态方面，包括未开发或开发不足的栖息地和极端环境，以寻找新的代谢物。本文报道了云南腾冲温泉可培养放线菌的多样性。从分布在三个地热田（例如，和华、热海和锐典）。通过对16 SrRNA基因和3个生物合成基因簇（PKS-I的KS结构域、PKS-II的KSα结构域和NRPS的A结构域）进行测序，分析了它们的系统发育位置和生物合成谱。根据16 S rRNA基因系统发育分析，这58株放线菌分属于12个放线菌属：Actinomadura Micromonospora、Microbispora、Micrococcus、Nocardiopsis、Nonomuraea、Promicromonospora、Pseudonocardia、Streptomyces、Thermoactinospora、Thermocatellispora和Verrucosispora，其中Thermoactinospora和Thermocatellispora是新发现的两个新属。考虑到这些放线菌菌株的生物合成潜力，22个阳性的PCR扩增的至少一个的三个生物合成基因簇（PKS-I，PKS-II，和NRPS）。这些放线菌进一步进行了对5种人类机会致病菌（鲍曼不动杆菌、大肠杆菌、藤黄微球菌、金黄色葡萄球菌和粪链球菌）的抗菌试验。对至少一个生物合成基因结构域的PCR扩增呈阳性的所有22个菌株对五种测试微生物中的至少一种表现出抗微生物活性。在剩余的36放线菌的生物合成基因的域的PCR扩增是阴性的，33株对至少一个测试病原体的抗菌活性。总之，本研究中的发现强调了未开发的栖息地（如腾冲温泉）作为寻找生物活性分子的潜在来源的重要性。
The class Actinobacteria has been a goldmine for the discovery of antibiotics and has attracted interest from both academics and industries. However, an absence of novel approaches during the last few decades has limited the discovery of new microbial natural products useful for industries. Scientists are now focusing on the ecological aspects of diverse environments including unexplored or underexplored habitats and extreme environments in the search for new metabolites. This paper reports on the diversity of culturable actinobacteria associated with hot springs located in Tengchong County, Yunnan Province, southwestern China. A total of 58 thermophilic actinobacterial strains were isolated from the samples collected from ten hot springs distributed over three geothermal fields (e.g., Hehua, Rehai, and Ruidian). Phylogenetic positions and their biosynthetic profiles were analyzed by sequencing 16S rRNA gene and three biosynthetic gene clusters (KS domain of PKS-I, KSα domain of PKS-II and A domain of NRPS). On the basis of 16S rRNA gene phylogenetic analysis, the 58 strains were affiliated with 12 actinobacterial genera:Actinomadura Micromonospora,Microbispora,Micrococcus,Nocardiopsis,Nonomuraea,Promicromonospora,Pseudonocardia,Streptomyces,Thermoactinospora,Thermocatellispora, andVerrucosispora, of which the two novel generaThermoactinosporaandThermocatellisoporawere recently described from among these strains. Considering the biosynthetic potential of these actinobacterial strains, 22 were positive for PCR amplification of at least one of the three biosynthetic gene clusters (PKS-I, PKS-II, and NRPS). These actinobacteria were further subjected to antimicrobial assay against five opportunistic human pathogens (Acinetobacter baumannii,Escherichia coli,Micrococcus luteus,Staphylococcus aureusandStreptococcus faecalis). All of the 22 strains that were positive for PCR amplification of at least one of the biosynthetic gene domains exhibited antimicrobial activities against at least one of the five test organisms. Among the remaining 36 actinobacteria that are negative for PCR amplification of the domains for the biosynthetic genes, 33 strains showed antimicrobial activities against at least one of the five test pathogens. In summary, the findings presented in this study emphasized the importance of underexplored habitats such as Tengchong hot springs as potential sources for search of bioactive molecules.