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

• Published in: Applied microbiology and biotechnology 1990-05, Vol.33 (2), p.226-232
• Main Authors: MISHRA, C, FORRESTER, I. T, KELLEY, B. D, BURGESS, R. R, LEATHAM, G. F
• Format: Article
• Language: English
• Subjects: arabinoxylan; Biological and medical sciences; Biotechnology; endo-1,4- beta -xylanase; Enzyme engineering; Fundamental and applied biological sciences. Psychology; glucuronoxylan; hydrolysis; Improved methods for extraction and purification of enzymes; Methods. Procedures. Technologies; xylooligosaccharides; xylose
• ISSN: 0175-7598; 1432-0614
• DOI: 10.1007/BF00176530

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- beta -D-xylanase (1,4- beta -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 degree C, with a K sub(m) of 0.66 mg/ml and specific activity of 310 units/mg protein at 40 degree 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.