These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Action of Trichoderma reesei and Aspergillus oryzae esterases in the deacetylation of hemicelluloses.
    Author: Tenkanen M.
    Journal: Biotechnol Appl Biochem; 1998 Feb; 27(1):19-24. PubMed ID: 9477552.
    Abstract:
    Xylans and mannans contain different esterified substituents such as acetyl, feruloyl and p-coumaroyl side groups. The functions of hemicellulose-deacetylating esterases of Trichoderma reesei and Aspergillus oryzae are discussed in this paper. Both fungi produce multiple esterases and two different esterases were isolated from both T. reesei and A. oryzae. The enzymes differed significantly in their substrate specificities. Acetyl xylan esterase of T. reesei was highly active on polymeric xylan but was unable to remove acetyl substituents from glucomannan or phenolic substituents from wheat straw arabinoxylan. Another esterase, acetyl esterase from T. reesei, had activity only towards short oligomeric and monomeric acetates derived both from xylan and glucomannan. The acetyl glucomannan esterase of A. oryzae was most active towards polymeric glucomannan, but was also able to remove acetyl groups from xylan. The only esterase studied which was active against phenolic substituents in arabinoxylans was the feruloyl esterase from A. oryzae. Feruloyl esterase had the widest substrate specificity of the esterases studied. It was also able to act on acetyl groups both in xylan and in glucomannan. The simultaneous enzymic liberation of acetyl groups from xylan and glucomannan clearly enhanced the action of xylan- and mannan-degrading enzymes, thus increasing the hydrolysis yield significantly. However, none of the esterases was able to remove all acetyl substituents when acting alone and simultaneous action of two esterases was needed for complete deacetylation.
    [Abstract] [Full Text] [Related] [New Search]