The effect of tunicamycin on production and secretion of extracellular carbohydrate-degrading enzymes by Postia placenta

IRG/WP 1342

J A Micales, T L Highley

The extracellular carbohydrate-degrading enzymes of wood-decay fungi are usually heavily glycosylated and therefore stable under most denaturing conditions. It is unlikely that wood decay can be prevented by simply inactivating these enzymes. Tunicamycin, an antibiotic produced by Streptomyces lysosuperificus, prevents the glycosylation of glycoproteins and can interfere with the secretion of these enzymes. The effect of tunicamycin on the production of extracellular carbohydrate-degrading enzymes of Postia placenta was determined in liquid culture. Enzyme production was inhibited at concentrations of 2.5-5 mg/ml; glycosidases were more sensitive than glycanases. Colony morphology was greatly altered at these concentrations, but dry weights decreased only 20-30%. The thermostabilities of xylanase and a-galactosidase, and the pH stability of xylanase, decreased when formed in the presence of low concentrations of tunicamycin. This suggests that the enzymes are produced in an active but nonglycosylated (or underglycosylated) form. The deglycosylation of glycoproteins may be a physiologically specific means of controlling wood-decay fungi.


Keywords: BROWN ROT; FUNGI; TUNICAMYCIN; GLYCOPROTEINS; GLYCOSIDASE; GLYCANASE; XYLANASE; GALACTOSIDASE; ENZYMES; POSTIA PLACENT

Conference: 88-04-24/29 Madrid, Spain


Download document (432 kb)
free for the members of IRG. Available if purchased.

Purchase this document