Вісник проблем біології і медицини (Dec 2020)
COMPOSITION ANALYSIS OF SOIL STREPTOMYCETES ENZYMES
Abstract
Streptomycetes have for a long time attracted attention of researchers in the fields of industrial microbiology, biotechnology and genetic engineering as producers of various nutrients. At present, almost 17 % of the biologically active of microbial secondary metabolites (about 7600 of the 43000 known) are isolated from streptomycetes. Nowadays, the products of streptomycete biosynthesis are used in various fields: in agriculture – for the treatment and prevention of bacterial and fungal infections, as growth stimulators and additives in animal feed, etc.; in the food industry – at canning of foodstuff with the maximum preservation of nutrients; in scientific research – to inhibit certain stages of biochemical transformations, cell destruction in order to isolate subcellular structures, in the cultivation of viruses, in genetic research, etc. Some of the main compounds that synthesize streptomycetes are enzymes, including hydrolytic, in particular proteinases, amylase, lipase, cellulase, DNAses, lytic enzymes and others. Lytic enzymes, by acting on the substrate, can be divided into bacteriolytic, myco- and yeast-elitic. Due to the lability of the enzymatic apparatus, members of the genus Streptomyces have a high antagonistic activity, which suppress the activity of other bacteria and fungi. Significant biosynthetic potential and incredible heterogeneity of streptomycetes determine the relevance of search for new producers and in-depth study of known microorganisms. Purpose: to determine the composition of enzymes in the culture liquid of strains; fractionation of protein complexes by gel filtration on Sephadex G-75 and comparison of their lytic activities. When determining the composition of enzymes in the culture fluid of the producers, it was found that all studied strains dissolved B. subtilis cells and only selected variants (S. recifensis 2P-15, P-29, 2.2 and 5.2) caused lysis of S. aureus cells. The yeast-lytic activity of streptomycetes was low, and in some strains (Streptomyces sp. 35, S. avermitilis AC-2179 and S. recifensis 6.2) it was not detected at all. The most active producer of proteinases was the rifampicin-resistant variant of S. recifensis 2P-15, and high amylolytic activity was demonstrated by variants of Streptomyces sp. 31, 2P-15 and P-29. Comparative analysis of lytic activity in the fractionation of enzymes on Sephadex G-75 showed that the most active is variant 2.2. It had the highest yield of staphylolytic activity for both high and low molecular weight proteins.Conclusions. Studies indicate a fairly high heterogeneity of the composition of enzyme complexes produced by streptomycetes. However, apparently, there are basic sets of genes encoding the most needful groups of enzymes, among which lytic enzymes, proteinases and amylase play an important role in the manifestation of antagonistic activity and food needs. Therefore, some of the studied strains can be use as objects for further optimization of enzyme synthesis, creation of overproducing strains and obtaining on their basis highly effective enzyme preparations.
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