The chitinolytic activity of Bacillus cohn bacteria antagonistic to phytopathogenic fungi

摘要

Among the 70 tested Bacillus spp. strains antagonistic to phytopathogenic fungi, 19 were found to possess chitinolytic activity when grown on solid media with 0.5 percent colloidal chitin. The chitinolytic activity of almost all of these 19 strains grown in liquid cultures ranged from 0.1 to 0.3 U/ml. One of the 19 strains exhibited exochitinase activity. In addition to chitinase, two strains also produced chitosanase and one strain, beta-1,3-glucanase. No correlation was found between the antifungal activity of the bacillar strains studied and their ability to synthesize extracellular chilinase. Among the 19 chitinolytic strains, the correlation between these parameters was also low (r_(x,y) = 0.45), although the enzymatic preparations of most ofthese strains inhibited the growth of the phytopathogenic fungus Helminthosporium sativum.