Several Separation Of Rare Actinomycetes From Medicinal Plant Rhizosphere Soil Classification And Identification Of Active Metabolism

Plant rhizosphere are special environment for microbial growth. The species and quantity are different from each other between rhizosphere and non- rhizosphere microbe. An increasing study indicated, some microbe had important activities isolated from rhizosphere environment, therefore rhizospheric microorganism are worth well to be reseached and developed.Isolation of rhizosphere actinomycetes from about 60 medicinal plant rhizosphere soil samples, which were collected from Yunnan province and Chongqing city was carried out with selective isolation methods to rare actinomycete. About 1000 strains were obtained. Systematic taxonomy were carried out about some isolates which selected according to their morphological characteristics and activities of metabolite, using polyphasic technology including morphological characteristic observation, physiological and biochemic tests, analysis of chemotaxonomy, 16S rDNA sequences, G+C contents, and DNA-DNA homologies etc. Their taxonomic status were finally determined based on their phenotypic, genetic and phylogenetic characteristics.In the nine rare strains identified, strain I05-00074~T was a novel species of genus Saccharopolyspora, for which strain I05-00074~T was proposed as Saccharopolyspora antimicrobica sp. nov., the thesis was published on IJSEM 2008, 58, 1180-1185; Strain I03-09939 represented a novel genus, for which strain I03-09939 was proposed as Actinoallosynnema gen. nov., sp. nov., with the name Actinoallosynnema albus sp. nov., and the paper was finished; Strain I06-02230 was a novel species of genus Actinopolymorpha, for which strain 106-02230 was proposed as Actinopolymorpha cephalotaxus sp. nov., and the paper was finished; Strain I06-02658 was a novel species of genus Glycomyces, for which strain I06-02658 was proposed as Glycomyces chongqingensis sp. nov., and the paper was prepared; Strain I06-03147 was a novel species of genus Kineosporia, for which strain I06-03147 was proposed as Kineosporia aconitum sp. nov., and the paper was prepared.Profuse bioactivity of rhizosphere actinomycetes were showed through fermentation and several model screening, including resist to Gram-positive bacterium, Gram-negative bacterium, yeast, mycelial fungus and other physiological activity. The total positive rate was 31%. We studied fermentation, isolation of bioactive components of strain I06-02230, the new strain of genus Actinopolymorpha, which owned activity of inhibitor SecA of Pseudomonas aeruginosa. 2230A was isolated and studied from fermentation broth of strain I06-02230, and 2230A was supposed to a new compound.The investigation was carried out first to medicinal plant rhizosphere actinomycetes of China about selectivity separate and bioactivity. The primary results were very important to learn about diversity of medicinal plant rhizosphere microbes in China. Meanwhile, a reliable experiment foundation was provided to exploit resources of medicinal plant rhizosphere in the future. In addition, with "new strain" producing "new bioactivity", this study fulfilled the screening strategy of "increasing efficiency and hit ratio in new drug screening through seeking new strains " and primary effects were gained.