ADAPTATION OF ASPERGILLUS TERREUS THOM STRAINS TO SALINE STRESS IN THE PRESENCE OF PHENOL COMPOUNDS IN SIMULATED CONDITIONS

Backgrounds. Fungi of the genus Aspergillus are stable residents of soil microbocenoses, are part of endophytic complexes of plant root systems, and play an important role in the processes of decomposition of lignocellulose complexes and humification. Dynamic balance and soil fertility are inextricably linked with the normal functioning of microbiocenoses. According to modern data, disturbed lands occupy vast areas in the world, in particular, saline soils – about 25 % of the entire land surface. In this regard, the aspects of adaptation of representatives of the resident microflora to the action of chemical stressors of the environment are of interest. The aim of this work is to assess the role of phenolic compounds – components of lignin molecules in the formation of resistance of cultures of the genus Aspergillus under conditions of salt stress under model conditions. Materials and methods. The objects of the study were strains of the filamentous fungus Aspergillus terreus Thom: At-09, Ater-12, Ater (Pnz)-12. The cultivation of the mycelium was carried out according to generally accepted methods. Salt stress for the cultures was created by adding sodium chloride to the nutrient medium in an amount of 0,5 M of the medium weight. Determination of the level of oxidative stress in the cultures was carried out using the determination of the marker compound – malondialdehyde (MDA). To determine the concentration of malondialdehyde (MDA) in the mycelium, the method of M. Michara et al. (1980) was used, based on the interaction of MDA and thiobarbituric acid (TBA). To assess the peroxidase activity of the mycelium, CAS-No.90-05-1 guaiacol (metox-syphenol) was used, which was introduced into the extract from the mycelium at a concentration of 0,4 mM. The peroxidase activity of the mycelium was judged by the change in the color of the nutrient medium, which illustrates the oxidation of guaiacol to quinone. The determination of the content of ergosterol in the mycelium was carried out by gas chromatography with derivatization of the unsaponifiable fraction of lipids extracted from the mycelium by the Folch method into trimethylsilyl derivatives. Statistical processing was carried out using “Statistica 6.0” program for data processing and analysis. Results. The results of studies of the effect of salt stress on the state of A. terreus mycelium revealed the manifestation of different degrees of pronounced signs of stress in the cultures of the studied strains. The c