PURIFICATION AND BIOCHEMICAL-CHARACTERIZATION OF BETA-XYLOSIDASE FROM HUMICOLA-GRISEA VAR THERMOIDEA

被引：7

作者：

DEALMEIDA, EM ^{[1
]}

POLIZELI, MDTM ^{[1
]}

TERENZI, HF ^{[1
]}

JORGE, JA ^{[1
]}

机构：

[1] UNIV SAO PAULO, FAC FILOSOFIA CIENCIAS & LETRAS RIBEIRAO PRET, DEPT BIOL, BR-14040901 RIBEIRAO PRETO, SP, BRAZIL

来源：

FEMS MICROBIOLOGY LETTERS | 1995年 / 130卷 / 2-3期

基金：

巴西圣保罗研究基金会;

关键词：

HUMICOLA GRISEA; BETA-D-XYLOSIDASE; XYLAN-DEGRADING ENZYME; THERMOPHILIC FUNGI;

D O I：

10.1016/0378-1097(95)00200-O

中图分类号：

Q93 [微生物学];

学科分类号：

071005 ; 100705 ;

摘要：

beta-D-Xylosidase production was maximal for Humicola grisea var. thermoidea grown on xylan as the sole carbon source. The main beta-D-xylosidase activity was localised in the periplasm. beta-Xylosidase was purified from crude extracts by heat treatment, ammonium sulfate precipitation and chromatography on DEAE-cellulose and Sephadex G-100. The purified enzyme was a monomer of molecular mass estimated to be 43 kDa by SDS-PAGE and gel filtration. Optima of pH and temperature were 6.0 and 50 degrees C, respectively. The enzyme activity was stimulated by Ca2+, Fe2+, and Mg2+. The purified beta-xylosidase did not exhibit xylanase, carboxymethylcelullase, galactosidase, glucosidase, fucosidase or arabinosidase activities. The purified beta-xylosidase hydrolysed xylobiose and xylo-oligosaccharides of up to five monosaccharide units. The enzyme had a K-m of 0.49 mM for p-nitrophenyl-beta-D-xylopyranoside and was not inhibited by its product, xylose.

引用

页码：171 / 175

页数：5

共 17 条

[1] XYLAN-DEGRADING ENZYMES OF THE YEAST CRYPTOCOCCUS-ALBIDUS - IDENTIFICATION AND CELLULAR-LOCALIZATION [J].