万寿菊内生和根际土壤放线菌的分离鉴定和抗菌活性研究

发布时间：2019-02-20 18:48

【摘要】：作为微生物中重要类群之一的放线菌,它可以产生许多具有抗菌活性的次级代谢产物。这些天然的活性产物在医疗行业、化工行业、农业以及环境污染治理方面都有广泛的应用。所以,从放线菌中发现新型抗生素成为了当今研究的热点。为了避免从已有的放线菌中的重复分离化合物,本研究选取了不同于传统的分离放线菌的分离源:植物和植物根际土壤,以期发现放线菌新种进而发现新型化合物。本研究所选取的分离源是万寿菊(Tagetes erecta L.)植株和植株根际土壤。经过多次反复分离,从万寿菊植株和植株根际土壤共分离得到了37株放线菌。并且对分离出来的37株放线菌分别对2种细菌和10中真菌进行了活性测试,结果显示:有5株放线菌的发酵液浸提物对两种细菌的抑制直径在15mm以上;有9株菌对2种以上真菌表现出较好抑制的作用,其中有2株放线菌的菌落对3种真菌的抑菌直径在20mm以上,只有1株放线菌对4种真菌的抑菌直径在20mm以上。对从万寿菊植株和根际分离出的37株放线菌的菌落形态、显微镜制片观察及活性测试的结果分析后,对NEAU-TWSJ13和NEAU-YJC4进行16S r DNA的基因测序。通过网站的比对和构建系统发育分析,NEAU-TWSJ13属于链孢囊菌属(Streptosporangium),NEAUYJC4属于小链孢菌属(Catellatospora)。其中,与NEAU-TWSJ13最相似的菌株是Streptosporangium fragile DSM 43847T,16S r RNA相似性是98.6%;与NEAU-YJC4 16S r RNA最相似的菌株是Catellatospora bangladeshensis JCM 12949T(98.7%)。通过与相似菌株进行形态特征比较、化学分类特征比较和分子分类特征比较,结果显示NEAU-TWSJ13和NEAU-YJC4在和其属菌的基本特征一致的情况下,还可以区别于属内的其他菌株。由此说明,NEAU-TWSJ13是链孢囊菌属的新种,NEAU-YJC4是小链孢菌属的新种,分别命名为Streptosporangium subfuscum和Catellatospora tagetis,并分别将它们送到中国、德国、日本菌种保藏中心进行保藏,保藏号分别为NEAU-TWSJ13(CGMCC 4.7146和DSM 46724)和NEAU-YJC4(CGMCC 4.7176和JCM 30053)。由此可见,把植物和植株根际土壤作为样本进行分离提高了发现新种的可能性,同时也为分离出新型活性物质奠定了基础。
[Abstract]:As an important group of microorganisms, actinomycetes can produce many secondary metabolites with antibacterial activity. These natural active products are widely used in medical industry, chemical industry, agriculture and environmental pollution control. Therefore, the discovery of new antibiotics from actinomycetes has become a hot spot. In order to avoid repeated isolation of compounds from existing actinomycetes, different from the traditional isolation of actinomycetes, plant and rhizosphere soil were selected in order to find new species of actinomycetes and then to find new compounds. The isolated source selected in this study is (Tagetes erecta L.). Plant and plant rhizosphere soil. After repeated isolation, 37 strains of actinomycetes were isolated from the rhizosphere soil and plants of marigold. The activity of 37 strains of actinomycetes was tested on 2 species of bacteria and 10 strains of fungi respectively. The results showed that 5 strains of actinomycetes had inhibitory diameter of more than 15mm on the two bacteria. 9 strains of actinomycetes showed better inhibition to more than 2 kinds of fungi. Among them, 2 strains of actinomycetes had inhibitory diameters over 20mm on 3 kinds of fungi, and only 1 strain of actinomycetes had inhibitory diameters above 20mm on 4 kinds of fungi. The colony morphology of 37 strains of actinomycetes isolated from marigold plants and rhizosphere, the results of microscopical observation and activity test were analyzed, and the 16s r DNA gene sequencing of NEAU-TWSJ13 and NEAU-YJC4 was carried out. Through the comparison and phylogenetic analysis of the website, NEAU-TWSJ13 belongs to the genus Alternaria, (Streptosporangium), NEAUYJC4 belongs to the genus Alternaria, and it belongs to (Catellatospora). The most similar strain to NEAU-TWSJ13 was Streptosporangium fragile DSM 43847 TX 16S r RNA, and the most similar strain to NEAU-YJC4 16S r RNA was Catellatospora bangladeshensis JCM 12949T (98.7%). The results showed that NEAU-TWSJ13 and NEAU-YJC4 could also be distinguished from other strains in the genus when they were consistent with the basic characteristics of their genus by comparing their morphological, chemical and molecular taxonomic characteristics with similar strains. Therefore, NEAU-TWSJ13 is a new species of the genus Alternaria, and NEAU-YJC4 is a new species of Alternaria, named Streptosporangium subfuscum and Catellatospora tagetis, respectively, and sends them to the preservation centers in China, Germany and Japan respectively. The storage numbers are NEAU-TWSJ13 (CGMCC 4.7146 and DSM 46724) and NEAU-YJC4 (CGMCC 4.7176 and JCM 30053) respectively. It can be seen that using the rhizosphere soil of plants and plants as samples improves the possibility of finding new species and lays a foundation for the separation of new active substances.
【学位授予单位】：东北农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S681.9;S182

【共引文献】