Formation and assessment of the phytoregulatory potential of multispecies biofilms based on Fischerella muscicola
L. I. Domracheva, I. G. Shirokikh, E. V. Tovstik, S. G. Skugoreva, E. N. Reznik
Section: Chemistry of natural environments and objects
The results of experiments on the study of the features of the formation of biofilms on the basis of two- and threecomponent associations of microorganisms with the participation of Fischerella muscicola 300 cyanobacteria, Streptomyces wedmorensis streptomycete 38.11 and Fusarium avenaceum 7/2 micromycete are presented in the article. When microorganisms are introduced into sterile soil, over the three months of exposure to light, in variants with a monoculture of cyanobacteria and with a three-component association, growths (biofilms) with a population density of a phototrophic component exceeding 50 million cells/cm2 are formed. In biofilms formed by two-component associations, cyanobacteria experienced inhibition by partners, reducing the number of cells 2.4–7.0 times, and the length of filaments 3.6–7.0 times, depending on the nature of the associate. The growth of the fischerella was limited by the streptomycete culture to a greater degree than by the fungus. In ground biofilms formed on the basis of cyanobacteria Fis. muscicola, the phytopathogenic fungus F. avenaceum, in the saprotrophic phase of development, is able to unite into single structured complexes with other participants in the multi-species consortium of microorganisms, including their antagonists. Aggregation of cells in biofilms is associated not only with the isolation of polysaccharide mucus cyanobacteria, but also with the creation of a net-thread structure of growth due to threads of cyanobacteria and mycelium of heterotrophic partners, the total length of
which can reach values exceeding 400 m/cm2. The development of such biofilms on the soil surface significantly increases its ability to retain moisture and prevent erosion. The two-component association of cyanobacteria and streptomycete
can be considered as promising for biocontrol of fusarium infection. At the same time, under specific conditions of the rhizosphere, the nature of the interaction of the cultures of microorganisms under investigation may differ from that
described for sterile soil lacking root exudates. Nevertheless, in experiments with the inoculation of Triticum aestivum L. seeds, it has been established that the two-component association of Fischerella muscicola + Streptomyces wedmorensis in
perspective can be used as a biological agent to limit the development of fusarium infection in the higher plant rhizosphere.
Keywords: cyanobacteria, streptomycetes, micromycetes, biofilm, density of populations, rhizosphere, microbial inoculation
Article published in number 2 for 2018 DOI: 10.25750/1995-4301-2018-2-117-124
ISSN 1995-4301
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