@article{mbs:/content/journal/micro/10.1099/00221287-132-6-1509, author = "St Leger, Raymond J. and Cooper, Richard M. and Charnley, A. Keith", title = "Cuticle-degrading Enzymes of Entomopathogenic Fungi: Regulation of Production of Chitinolytic Enzymes", journal= "Microbiology", year = "1986", volume = "132", number = "6", pages = "1509-1517", doi = "https://doi.org/10.1099/00221287-132-6-1509", url = "https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-132-6-1509", publisher = "Microbiology Society", issn = "1465-2080", type = "Journal Article", abstract = "Synthesis of chitinase and chitosanase by the entomopathogenic fungus Metarhizium anisopliae is regulated by products of chitin and chitosan degradation through an inducer-repressor mechanism. Slow-feeding with sugars or alanine (about 20 μg ml−1 h−1) in a carbon deficient medium to prevent catabolite repression (restricted cultures) demonstrated that the most effective inducers of chitinase and chitosanase were the principal monomeric constituents of chitin (N-acetylglucosamine) and chitosan (glucosamine) respectively. Increasing the rate of release of N-acetylglucosamine decreased chitinase synthesis by about 87% while causing a sevenfold increase in growth. In batch cultures high chitinase activities were present only in chitin-containing medium. There was a negative correlation between accessibility and amount of chitin substrates, levels of free N-acetylglucosamine in culture fluids and chitinase production. Addition of carbohydrates, lipid or proteins to chitin-grown cultures repressed chitinase production. Basal levels of chitinase were produced in non-inducing media. Production of chitobiase (N-acetylglucosaminidase) was enhanced from high basal levels by amino sugars, but was less inducible and less susceptible to catabolite repression than chitinase.", }