Induction of Cellulose- And Xylan-Degrading Enzyme Systems in Aspergillus Terreus by Homo- And Heterodisaccharides Composed of Glucose and Xylose

J Gen Microbiol. 1991 Mar;137(3):541-7. doi: 10.1099/00221287-137-3-541.

Abstract

Synthetic heterodisaccharides composed of glucose and xylose were tested as inducers of cellulose- and xylan-degrading enzymes in Aspergillus terreus, and the inducing abilities were compared with those of sophorose and xylobiose or their positional isomers. Measurement of secreted and cell-associated enzyme activities revealed that the heterodisaccharides induced the synthesis of the cellulolytic and xylanolytic enzymes, 2-O-beta-D-glucopyranosyl D-xylose (Glcbeta 1-2Xyl) being the most powerful inducer. Sophorose and 2-O-beta-D-xylopyranosyl D-Xylose (Xylbeta 1-2Xyl), or their positional isomers, selectively induced the synthesis of cellulases and beta-xylanases, respectively. An analysis of the extracellular enzymes (which were separated by isoelectric focusing followed by detection using chromogenic and fluorogenic substrates) showed that Glcbeta 1-2Xyl initiated the synthesis of specific endo-1,4-beta-glucanases and specific endo-1,4-beta-xylanases identical to those produced separately in response to sophorose or Xylbeta 1-2Xyl. Glcbeta 1-2Xyl also induced specific endo-1,4-beta-glucanases that hydrolysed 4-methylumbelliferyl beta-lactoside at the agluconic bond. The results strengthen the concept of separate regulatory control of the synthesis of cullulases and beta-xylanases. The results also suggest that mixed disaccharides, composed of glucose and xylose moieties, which may occur in nature, could play an important role in regulating the synthesis of wood-degrading enzymes.

MeSH terms

  • Aspergillus / enzymology*
  • Carbohydrate Sequence
  • Cellulase / metabolism
  • Cellulose / metabolism*
  • Disaccharides / metabolism*
  • Enzyme Activation
  • Glucose / metabolism*
  • Glycoside Hydrolases / metabolism*
  • Molecular Sequence Data
  • Xylan Endo-1,3-beta-Xylosidase
  • Xylans / metabolism*
  • Xylose / metabolism*

Substances

  • Disaccharides
  • Xylans
  • Cellulose
  • Xylose
  • Glycoside Hydrolases
  • Xylan Endo-1,3-beta-Xylosidase
  • Cellulase
  • Glucose