[Essential expression and inducible synthesis polymorphism of chitinase in XXXX ].

@entity11137 @entity413
Chitinases were produced by a lot of microorganisms. Chitinase gene expression in most of the chitinase producing bacteria was inducible by chitin. Low levels of chitinase were observed in the presence of @entity413 . To date, however, the regulation of such chitinase gene in @entity11137 had not been well studied. In this paper, all 77 @entity11137 strains were grown in the medium with or without chitin. We measured quantitatively the chitinase activity of the cultures. Moreover, we investigated the suppressive effect of @entity413 on chitinase of 4 strains. Also we studied the relationship between chitin induction and @entity413 suppression on chitinase. This investigation demonstrated that all tested @entity11137 strains could produce chitinase without chitin. After induction, the chitinolytic activity of 31 tested strains had no obvious response to the inducer, whereas 44 stains increased in different degree. Among these strains, most of them did not markedly increase the levels of chitinase, and many stains simultaneously displayed the expression mode of inducible and constitutive. The @entity413 inhibited the inductive effect of chitin, but it could not inhibit the basal expression of chitinase. Two strains No. 38 and No. 75 belonged to different expression types. But we just found several different bases in the regulatory region of chitinase genes chiA and chiB from them.
