摘要
从顶青霉 (Pencilliumcorylophilum)P 3 31培养液中分离到 3种木聚糖酶组分 ,分别称为PartA、PartB和PartC .PartB进一步纯化 ,经SDS PAGE鉴定为单带 ,相对分子质量为 2 4 2 0 0 ;PartC进一步纯化 ,经SDS PAGE鉴定也是单带 ,相对分子质量为 4 830 0 .PartA和PartB的最适反应条件为 pH 4 .0 ,4 5℃ ;PartC的最适反应条件为pH 5.5,55℃ .PartA和PartB对木聚糖以外的底物不能水解 ;PartC具有水解CMC的交叉活性和 β 木糖苷酶活性 ,但不能将木二糖水解成木糖 .3个纯化酶组分和粗酶对不同来源的木聚糖底物均表现出不同的活性 .对于粗酶 ,若桦木木聚糖为底物的相对酶活为 10 0 % ,则玉米芯木聚糖为底物的相对酶活为 143% ,蔗渣木聚糖为底物的相对酶活为 12 4 % .
Three parts of xylanases (Part A, Part B and Part C) were separated and purified from a culture filtrate of Pencillium corylophilum No.P 3 31. Part B was further purified to homogeneity and Part C was further purified to almost homogeneity by the same procedures as Part B. The molecular weights of Part B and Part C were estimated to be 24 200 and 48 300 respectively by SDS PAGE. The optimal pH and temperature of enzymes were 4.0 and 45 ℃ for Part A and Part B, while 5.5 and 50～55 ℃ for Part C. Part C showed a substrate cross specificity on hydrolyzing CMC and had an activity of β xylosidase, but this activity was unable to hydrolyze xylobiose. Part A and Part B did not show the substrate cross specificity. Both crude and purified enzymes showed significant differences in their activities to hydrolyze different xylans from different sources. For the crude enzyme, if the activity to birchwood xylan was set as 100%, then those to corncob xylan and bagasse xylan were 143% and 124% respectively.
出处
《无锡轻工大学学报（食品与生物技术）》
CSCD
北大核心
2001年第1期35-39,共5页
Journal of Wuxi University of Light Industry
关键词
顶青霉
木聚糖酶
纯化
底物特异性
Pencillium corylophilum
xylanase
purification
substrate specificitl
