STUDYING REPRESENTATIVES OF WHEAT GRAIN MICROBIOTA RESISTANT TO COPPER, ZINC, MANGANESE AND IODINE SALTS

Abstract

There was studied the species composition of the wheat grain microbiota, representatives of which could be potential producers of organic compounds for modern biotechnology. Twenty wheat (Triticum vulgaris) samples were tested, from microbiocenoses of which the strains of heterotrophic microorganisms resistant to toxic concentrations of copper, zinc, manganese and iodine salts were isolated and described. The contents of zinc, manganese and copper salts in a suspension of washed bacterial cells were determined using a highly sensitive multielement analysis method of inductively coupled plasma mass spectrometry (ICP-MS). Using media containing manganese, we isolated and identified Stenotrophomonas maltophilia, Bacillus cereus, Lactococcus lactis, Bacillus subtilis, Brevibacillus sp., Bacillus amyloliquefaciens. Using a medium containing 1% KJ, we isolated Vagococcus sp., Paenibacillus dendritiformis and three unidentified isolates. On a nutrient medium containing copper sulfate, one isolate of an unknown species was grown. In the presence of 1% zinc sulfate, Klebsiella pneumonia, Enterococcus faecalis, Enterococcus faecium, Ralstonia insidiosa, Stenotrophomonas maltophilia have grown that allows using them for the development of selective media. Bacteria of the genus Bacillus have been detected, which are characterized by the ability to accumulate copper compounds to a concentration of 22.3 mg/g dry biomass. The 16S rRNA gene fragment from this culture has the greatest, but incomplete (98%), homology with Bacillus sp. LY (Genbank AY787805). No data on species identity of this Bacillus strain are available in the literature studied that allows us to refer it and isolated strain Cu2 to a new species, which has not previously been described.