STUDY OF THE EFFECT OF ISOTHIOCYANATES RELEASE FROM BENTONITE BASED COMPLEXES ON THE MICROBIOTA OF FOREST SOIL

Isothiocyanates (ITCs) are substances formed in the result of hydrolysis of glucosinolates and widely found in plants of the cruciferous and Solanaceae families. ITCs are used in agriculture, medicine and the food industry. This article describes the preparation of complexes based on 3 types of ITCs (allyl isothionate (AITC), benzyl isothionate (BITC) and 2-phenylethyl isothiocinate (PEITC)) and their effect on ecologotrophic groups (ETG) of forest soil microorganisms. It has been proved that the deposition of ITC in bentonite contributes to the prolonged release of AITC, BITC, PEITC and reduces the time of their hydrolysis in the soil. Application of free forms of ITC decreased the number of ammonifiers by 2.6 times (when AITC was added), increased the number of nitrogen fixers up by 1.2 times (when BITC was added), and decreased the number of actinomycetes by 21, 1.4 and 1.9 times when AITC, PEITC and BITC were used, respectively. The number of micromycetes increased only when PEITC and BITC were introduced into the soil. The introduction of ITC/bentonite complexes into the soil resulted in a significant decrease in the number of ammonifiers for AITC/bentonite and PEITC/bentonite samples. The introduction of AITC/bentonite complex into the soil increased the number of nitrogen fixers, actinomycetes and micromycetes. The deposition of PEITC and BITC in the bentonite also led to an increase in the number of micromycetes and nitrogen fixers, respectively, which is most likely due to their low concentrations in contrast to free ITC.