Identification Of Marigold Endophyticand Rhizosphere Actinomycetes And Study On Antimicrobial Activity

Actinomycetes is an important group of microbes, it can produce a lot of secondary metabolites with antibacterial activity. These products of natural active have been applied widely in the medical industry, chemical industry, agriculture and environmental pollution treatment. So, to isolate new antibiotics from actinomycetes become the focus of current research. In order to avoid the compounds isolated from existing repetition of actinomycetes, this study selected the source: different from the traditional separation of actinomyces separation plants and plant rhizosphere soil, in order to find actinomyces species and found that the new compounds.This study selected marigold(Tagetes erecta l.) plant and rhizosphere of marigold as the separated source of actinomycetes. After many repeated separation, 37 strains actinomycetes were isolated from marigold plants and rhizosphere of marigold. And the 37 strains of actinomycetes were tested activity on the two bacteria and ten funguses, results showed that 1 actinomycetes strains fermented liquid extraction content of two kinds of bacteria inhibition activity in more than 15 mm; 9 strains of actinomycetes colonies are activated to restrain activity of ten kinds of pathogenic fungi is stronger, among them 2 strains of colonies bacteriostatic diameter of three kinds of fungi in more than 20 mm, only a colony of four kinds of fungi strains actinomycetes bacteriostatic over 20 mm in diameter.Through to analysis 37 strains of morphological observation, microscopic observation and the result of the activity, NEAU-TWSJ13 and NEAU-YJC4 were got 16 S r RNA gene sequence. By comparing of gene sequence of site and construct phylogenetic analysis, NEAU-TWSJ13 belonged to the chain Streptosporangium, NEAU-YJC4 belonged to Catellatospora. Then, NEAU-TWSJ13 was the most similar with Streptosporangium fragile DSM 43847, the similarity of 16 S r RNA was 98.6%; NEAU-YJC4 was the most similar with strains Catellatospora bangladeshensis JCM 12949(98.7%). By comparing with morphological characteristics, chemotaxonomic characteristics, DNA-DNA relatedness and(G+C) mol%, the results showed NEAU-TWSJ13 and NEAU-YJC4 were novel species of the genus Streptosporangium and Catellatospora, they can also be distinguished from other strains within the genus. They had named Streptosporangium subfuscum and Catellatospora tagetis, and sent to the Chinese academy of sciences institute of microbiology, Germany of microbial culture collection center and Japan biological culture collection center for preservation, the preservation number is CGMCC 4.7146 T and DSM 46724T)and NEAU-YJC4(CGMCC 4.7176 Tand JCM 30053T). Thus, the endophytic actinomycetes and rhizosphere of plant as sample separation sourece can increase the chances of discovering new actinomycetes, also has laid the foundation for the isolated of new compound.