Soil Streptomyces Sp. Strain 2k1: Phylogenetic Position, Effect On Fusarium Proliferatum Growth

The article presents the results of a study of the phylogenetic position of the strain 2K1 and the effect of volatile substances (VS) on the growth of Fusarium proliferatum AC. Strain 2K1 was isolated from Kirov region soil. The strain 2K1 identification was carried out using cultural-morphological, physiological-biochemical features, as well as on the basis of analysis of the 16S rRNA gene partial sequence. The species of the strain 2K1 has not been established by the methods used. The closest related species of strain 2K1 according to phylogenetic analysis is Streptomyces fulvissimus strain SS-A28 ( M K611756). Reliability of clustering within a single node of the phylogenetic tree at bootstrap 1000 is 86%. in the double culture experiments, the metabolic effect of VS of the strain 2K1 on the radial growth rate of the F. proliferatum AC fungus was studied. The strain AC belonging to Fusarium genus is confirmed by molecular genetic analysis results. It was found that VS of strain 2K1 reduce the rate of radial growth of F. proliferatum AC culture by more than 2 times at the age of 14 days. This allows speaking about the predominant effect of VS on the development of fungal hyphae, but not spores. According to gas chromatography mass spectrometry, volatile organic compounds of strain 2K1 include substances belonging to different classes of organic compounds. Among them are derivatives of alcohols, organic acids, mercaptans and esters are present. It is assumed that the inhibitory effect of VS strain 2K1 is determined by methylhydroxylamine. Since VS are able to easily overcome phase boundaries, the strain 2K1 can be recommended as a biocontrol agent against the F. proliferatum. The sequences of the 16S rRNA gene of Streptomyces sp. strain 2 K1 and the ITS region of strain F. proliferatum AC are deposited in GenBank (accession numbers MT280320 and MT280199 respectively).