Characterization of a major xylanase purified from Lentinula edodes cultures grown on a commercial solid lignocellulosic substrate.

Autor: Mishra, Chittra, Forrester, Ian, Kelley, Brian, Burgess, Richard, Leatham, Gary
Zdroj: Applied Microbiology & Biotechnology; 1990, Vol. 33 Issue 2, p226-232, 7p
Abstrakt: The white-rot basidiomycete Lentinula (syn. Lentinus) edodes (Berk.) Pegler is the dominant edible mushroom cultivated on wood. The major xylanase detected in cultures grown on a commercial oak wood medium was extracted, purified, and characterized. The enzyme was a non-debranching endo-β- d-xylanase (1,4-β- d-xylan xylanohydrolase; E.C.3.2.1.8) highly specific for xylans, with a molecular weight of 41 000 (on sodium dodecyl sulfate gels) and an isoelectric point of 3.6. With aspen glucuronoxylan as substrate, the enzyme showed optimal activity at pH 4.5-5.0 and 60° C, with a K of 0.66 mg/ml and specific activity of 310 units/mg protein at 40° C. It was capable of hydrolyzing (forming reducing sugars from) 40%-50% of the hydrolyzable linkages in either glucuronoxylan or arabinoxylan. The enzyme produced xylose and major identifiable products in the xylobiose or xylotriose (and presumably larger) size range including xylobiose and xylooligosaccharides, but neither glucuronic acid nor arabinose. Products were also produced from arabinoxylan that appeared to be arabinoxylobiose and arabinoxylotriose. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index