本文選題：北侖河口 + 紅樹林　； 參考：《桂林醫(yī)學(xué)院》2017年碩士論文

【摘要】：目的:探究廣西北侖河口紅樹林植物根際土壤放線菌資源多樣性并進行抗菌活性研究,為新抗生素發(fā)現(xiàn)提供藥用放線菌資源。方法:采用5種分離培養(yǎng)基,以稀釋涂布法分離放線菌;通過PCR擴增獲得菌株16S r RNA基因并進行同源性比對,分析放線菌多樣性;發(fā)酵液經(jīng)乙酸乙酯萃取,菌絲經(jīng)丙酮浸泡,分別獲得發(fā)酵液水相、發(fā)酵液酯相和菌絲丙酮浸提液三類樣品;標準紙片擴散法進行抗菌活性的篩選;抗菌活性菌株應(yīng)用PCR擴增對其進行PKS I、PKS II及NRPS生物合成基因的篩選。結(jié)果:來自廣西北侖河口紅樹林保護區(qū)的7份紅樹林植物根際土壤樣品,從中分離純化得到放線菌110株,歸屬于放線菌綱的7個目9個科15個屬,優(yōu)勢菌屬為小單孢菌屬和鏈霉菌屬;菌株N04M112、3804M13、Z05M23、Z07M34的16S rRNA基因序列與有效發(fā)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,分別為97.49%、98.42%、98.58%、98.54%,可能為潛在新物種;抗菌活性檢測結(jié)果表明,51株放線菌中,46株有抗菌活性,總陽性率為90.20%;對這46株放線菌的抗生素生物合成基因探測發(fā)現(xiàn),10株同時具有PKS I、PKS II及NRPS生物合成基因,42株至少含有其中一種基因,總陽性率91.30%。結(jié)論:廣西北侖河口紅樹林植物根際土壤中含有較為豐富的放線菌資源,具有從中發(fā)現(xiàn)放線菌新物種、新抗生素的潛力。
[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鑿屽睘鍜岄摼闇夎弻灞，

本文編號：1769467