Bioactivity Study Of Endophytic And Rhizospheric Actinomycetes From Paris Polyphylla And Taxonomic Identification Of Catellatospora Paridis

Medicinal plants constitute a huge diversity of microorganisms, and plant-associated microorganisms can produce the same or similar active compounds as their host plant. These microorganisms not only have antibacterial, anti-virus, anti-tumor activity, but also can promote the healthy growth of plants. Paris polyphylla is a precious traditional Chinese medicine, the plant contains sterols, saponins, polysaccharides and other active compounds. In this study, we selected the different sources of the traditional separation of actinomycetes: Paris polyphylla and its rhizosphere soil, in order to find the new plant-growth promoting actinobacteria and find a new type of compound.125 actinomycetes strains were isolated from roots and rhizosphere soil of the medicinal plants of Paris polyphylla. Their morphological characteristics and cultural characteristics combining the result of 16 S r RNA sequence analysis can determine that these strains belong to the genus Streptomyces, Micromonospora, Microstreptospora and Rhodococcus. The number of rhizosphere actinomycetes occupied 69% of the total isolates, and endophytic actinomycetes accounted for 31%. The genus Streptomyces has the largest proportion in it(at about 50.5%), while Microstreptospora has a smaller proportion than Streptomyces(at about 34.7%). The genus Streptomyces accounted for 38.1% of the isolate in rhizosphere. Similarly, the microstreptospora is closely followed, accounting for about 33.3%. 11 strains of these actinomycetes strains were found to have antifungal activity, and two of them had inhibitory effects on both two kinds of pathogenetic bacterium. Moreover, the inhibitory effect of rhizosphere actinomycetes was more obvious than endophytic actinomycetes.In the experiment, a strain of Streptomyces CL-3 with good antifungal activity was found, which had a certain inhibition effect on the 14 species tested fungi, and the inhibition rate reached 80%. In wheat seed germination experiment, it was found that the concentration of 1.7×104cfu·m L-1-1.7×102cfu·m L-1 spore liquid has an excellent growth-promoting effect on seed germination and seedling growth. The greenhouse experiment of strain CL-3 found that the strain can boost plants’ growth. It was confirmed a kind of plant-growth promoting actinobacteria.Strain NEAU-CL2 T was isolated from the rhizosphere soil of Paris polyphylla. Its 16 S rRNA gene sequence similarity studies and its key morphological and chemotaxonmic properties were confirmed that the affiliation of strain NEAU-CL2 T to the genus Catellatospora. A combination of DNA-DNA hybridization results and some phenotypic characteristics indicated that strain NEAU-CL2 T can be clearly distinguished from its closest related species of the genus Catellatospora. In conclusion, strain NEAU-CL2 T represents a novel species of the genus of Catellatospora, for which the name Catellatospora paridis sp. nov. is proposed. The type strain is NEAU-CL2~T.