HYDROLYZING ACTIVITY OF CGTASES FROM PAENIBACILLUS IN RELATION TO α AND β GLICANS

The cell wall of micromycetes is crucial for the shape and function of cells, as well as for their protection from environmental influences and contains up to 80-90 % of polysaccharides with different types of bonds. Cyclodextrin glucanotransferase microorganisms were tested and the following strains were selected Paenibacillus ehimensis IB-739, Paenibacillus illinoisensis IB-1087, Paenibacillus sp. IB-663, Paenibacillus macerans IB-I4. These strains were able to hydrolyze homopolysaccharides (starch, carboxyme-thylcellulose) and heteropolysaccharides (glucomannan, galactomannan). Cyclodextrin glucanotransferase (CGTase, EC 2.4.1.19) is a multifunctional enzyme capable of catalyzing various types of reactions: cyclization, binding, disproportionation and hydrolysis. It was found that strains and their preparations of CGTase, in addition to cyclizing activity, have a hydrolyzing ability against α- and β-glicans. The method of cluster analysis for strains revealed substrate preferences during hydrolysis in favor of α glicans (P. ehimensis IB-739, Paenibacillus sp. IB-663) or β-glicans (P. illinoisensis IB-1087, P. macerans IB-I4). The advantage of the preparative form of the CGTase enzyme when exposed to the components of the fungal cell wall (α-glicans and β-glicans) in comparison with the intact effect of cellular hydrolases is shown. The culture of P. macerans IB-I4, whose CGTase equally hydrolyzes all the presented polymers, turned out to be the most active in terms of the degree of destruction of glicans. The prospect of using CGTase enzyme preparations as agents in the fight against phytopathogenic fungi is discussed.