广西北仑河口红树林根际土壤放线菌多样性及抗菌活性研究

发布时间：2018-04-18 18:06

  本文选题：北仑河口 + 红树林　； 参考：《桂林医学院》2017年硕士论文

【摘要】：目的:探究广西北仑河口红树林植物根际土壤放线菌资源多样性并进行抗菌活性研究,为新抗生素发现提供药用放线菌资源。方法:采用5种分离培养基,以稀释涂布法分离放线菌;通过PCR扩增获得菌株16S r RNA基因并进行同源性比对,分析放线菌多样性;发酵液经乙酸乙酯萃取,菌丝经丙酮浸泡,分别获得发酵液水相、发酵液酯相和菌丝丙酮浸提液三类样品;标准纸片扩散法进行抗菌活性的筛选;抗菌活性菌株应用PCR扩增对其进行PKS I、PKS II及NRPS生物合成基因的筛选。结果:来自广西北仑河口红树林保护区的7份红树林植物根际土壤样品,从中分离纯化得到放线菌110株,归属于放线菌纲的7个目9个科15个属,优势菌属为小单孢菌属和链霉菌属;菌株N04M112、3804M13、Z05M23、Z07M34的16S rRNA基因序列与有效发表菌株Agromyces humatus CD5T(AY618216)、Streptomyces atrovirens NRRLB-16357T(DQ026672)、Streptosporangium jomthongense 30EHST(JQ922513)、Micromonospora wenchangensis2602GPT1-05T(JQ768361)的相似率最高,分别为97.49%、98.42%、98.58%、98.54%,可能为潜在新物种;抗菌活性检测结果表明,51株放线菌中,46株有抗菌活性,总阳性率为90.20%;对这46株放线菌的抗生素生物合成基因探测发现,10株同时具有PKS I、PKS II及NRPS生物合成基因,42株至少含有其中一种基因,总阳性率91.30%。结论:广西北仑河口红树林植物根际土壤中含有较为丰富的放线菌资源,具有从中发现放线菌新物种、新抗生素的潜力。
[Abstract]:Objective: to explore the diversity and antibacterial activity of actinomycetes in the rhizosphere of mangrove plants in Beilun estuary, Guangxi, and to provide medicinal actinomycetes for the discovery of new antibiotics.Methods: actinomycetes were isolated by dilution coating method on 5 kinds of culture medium, 16s r RNA gene was obtained by PCR amplification and homology was compared to analyze the diversity of actinomycetes. The fermentation broth was extracted by ethyl acetate, and the hyphae was soaked in acetone.Three kinds of samples, water phase, ester phase and acetone extract, were obtained, the antibacterial activity was screened by standard disk diffusion method, and the PKS IPKS II and NRPS biosynthesis genes were screened by PCR amplification.Results: from 7 mangrove plant rhizosphere soil samples from Beilun estuary mangrove reserve in Guangxi, 110 strains of actinomycetes were isolated and purified, belonging to 7 orders, 9 families and 15 genera of actinomycetes.浼樺娍鑿屽睘涓哄皬鍗曞�㈣弻灞炲拰閾鹃湁鑿屽保�

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