Screening, Primary Antibiotic Activity Research Of Actinomycetes From Veratrum Nigrum L. Root And Identification Of Plantactinospora Veratri

Applying of conventional technology and drugresistance of pathogens ma kes it difficult to screen out new actinomycetes species and new compounds. This shifts people ’s focus to animal and plant, marine and marsh separation resources. Medicinal plants could produce kinds of actitivity substances, and actinomycetes co-exist with them for a long period, so probably gene-transfer phenomenon occurred between them, which would make actinomycetes produce the same or similar substance. Thus, a medicinal plant Vertrum nigrum L. was chosen as separation resources, which would increase the possibility of screening out natural metabolites within endophytic actinomycetes from medicinal plant, and provide some promising strains for further research.In the experiment, medicinal plants Vertrum nigrum L. were collected on Mountain Fenghuang in Wuchang of Heilongjiang. The roots were chosen as separation resource of actinomycetes, and four kinds of media adopted as screening cultivation. The plate method and opposing method was used to determine antagonistic activity of these endophytic actinomycetes. One of the strains, NEAU–FHS4, was rarely isolated, and it has respressive activity to Bacillus subtilis, so polyphasic test were carried on this strain. There were some main results:(1) In the experienment, actinomycetes in 3 medicinal plant false b lack hellebore’ roots were screened. Respectively, 7, 15, 4 and 1 strains were got from HV medium, Gauze’s medium no. 1 and modified Gause II meidium and GGXAG medium. Altogether, 27 strains were isolated, and most of them distributed in family of Streptomycetaceae and Micromonosporaceae according to morphological observation.(2) In the anti-bacterial test, there were 9 strains LL1, LL2, LL3, LL4(NEAU–FHS4), LL7, LL16, LL18, LL20 and LL25 showing repressive activity to at least one kind of the bacteria Bacillus subtilis and Micrococus luteus; In the anti-fungus activity test, 4strains(LL1, LL2, LL7, LL18) were capable to repress at least three kinds of the fungus to moderate degrees. One of the stains LL2 could repress 2 kinds of indicator bacteria and 9 kin ds of pathogen fungus, which showed its broad range activity.(3) One of the strains, NEAU–FHS4, was rarely isolated, and it has respressive activity to Bacillus subtilis, so polyphasic test were carried on this strain. Firstly, the sequencing of 16 S r DNA and systematic analysis indicated that it formed a clade with the other three species of genus Plantactinospora. Then, it was confirmed that the strain NEAU–FHS4 was a new species of genus Plantactinospora by being compared with its similar stains in morphological characterization, intolerance and zymetological experiment, cellular chemical composition and molecular level homology. Therefore, stain NEAU–FHS4 represents a new species of the genus Plantactinospora, for which the name Plantactinospora veratri sp. nov. was proposed. The name of the strain was valid, and an article about this was published on SCI journal IJSEM.