Purification and characterisation of a β-galactosidase from Aspergillus aculeatus with activity towards (modified) exopolysaccharides from Lactococcus lactis subsp cremoris B39 and B891

被引：22

作者：

van Casteren, WHM ^{[1
]}

Eimermann, M ^{[1
]}

van den Broek, LAM ^{[1
]}

Vincken, JP ^{[1
]}

Schols, HA ^{[1
]}

Voragen, AGJ ^{[1
]}

机构：

[1] Univ Wageningen & Res Ctr, Dept Agrotechnol & Food Sci, Food Chem Lab, NL-6703 HD Wageningen, Netherlands

来源：

CARBOHYDRATE RESEARCH | 2000年 / 329卷 / 01期

关键词：

beta-galactosidase; Aspergillus aculeatus; exopolysaccharide; Lactococcus lactis subsp cremoris; enzymic modification;

D O I：

10.1016/S0008-6215(00)00152-X

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

beta-Galactosidase from Aspergillus aculeatus was purified from a commercial source for its hydrolytic activity towards (modified) exopolysaccharides (EPSs) produced by Lactococcus lactis subsp. cremoris B39 and B891. The enzyme had a molecular mass of approximately 120 kDa, a pi between 5.3 and 5.7 and was optimally active at pH 5.4 and 55-60 degrees C. Based on the N-terminal amino acid sequence, the enzyme probably belongs to family 35 of the glycosyl hydrolases. The catalytic mechanism was shown to be retaining and transglycosylation products were demonstrated using lactose as a substrate. The beta-galactosidase was also characterised using its activity towards two EPSs having lactosyl side chains attached to different backbone structures. The enzyme degraded O-deacetylated EPS B891 faster than EPS B39. Furthermore, the presence of acetyl groups in EPS B891 slowed down the hydrolysing rate, but the enzyme was still able to release all terminally linked galactose. (C) 2000 Elsevier Science Ltd. All rights reserved.

引用

页码：75 / 85

页数：11

共 39 条

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