Purification and properties of an acetylxylan esterase from Fibrobacter succinogenes S85

Autor: C R MacKenzie, Cecil W. Forsberg, K P McDermid
Rok vydání: 1990
Předmět:
Zdroj: Applied and Environmental Microbiology. 56:3805-3810
ISSN: 1098-5336
0099-2240
DOI: 10.1128/aem.56.12.3805-3810.1990
Popis: An acetylxylan esterase (EC 3.1.1.6) was purified to apparent homogeneity from the nonsedimentable extracellular culture fluid of Fibrobacter succinogenes S85 grown on cellulose. This enzyme had an apparent molecular mass of 55 kDa and an isoelectric point of 4.0. The temperature and pH optima were 45 degrees C and 7.0, respectively. The apparent Km and Vmax were 2.7 mM and 9,100 U/mg, respectively, for the hydrolysis of alpha-naphthyl acetate. The enzyme cleaved acetyl residues from birchwood acetylxylan but did not hydrolyze carboxymethylcellulose, larchwood xylan, ferulic acid-arabinose-xylose polymer, p-nitrophenyl-alpha-L-arab-inofuranoside, or longer-chain naphthyl fatty acid esters. The esterase enzyme may play a role in enhancing hemicellulose degradation by F. succinogenes, thereby allowing it greater access to cellulose present in forage cell walls.
Databáze: OpenAIRE