摘要
研究了1株嗜热菌（Anoxybacillus flavithermus）所产木糖异构酶的分离纯化以及酶学性质。结果表明，经硫酸铵沉淀、SephadexG-5凝胶过滤、纤维素DE-2弱阴离子交换柱和QSepharoseFastFlow强阴离子交换层析得到的木糖异构酶，分子量约为181ku，由4个相同分子量的亚基组成。酶反应的最适温度为80℃，最适为pH为7．0且最适pH范围宽泛，pH6．0-11．0酶反应活性能保持80％左右。该酶热稳定性及耐碱性能良好，70℃保温1h后酶活仍能保持近80％左右；pH5．0—8．0保温1h后酶活仍能保持近80％以上，甚至pH12．0保温1h后酶活性仍能保持40％左右。Mn2＋和Co2＋对酶活性有明显促进作用，Zn2＋、Cu2＋以及AL3＋对酶活性有一定程度的抑制。
A xylose isomerase produced by thermophilic bacterium Anoxybacillus flavithermus was purified using Sephadex G -75 gel filtration,DEAE-cellulose anion exchange chromatography and Q Sepharose Fast Flow anion exchange chromatography. The estimated molecular mass of the purified xylose isomerase was 181 ku and was made up of four sub-groups. The optima temperature and pH of enzymatic reaction were 80℃ and pH 7.0, respectively. This xylose isomerase is alkali- tolerant and thermo-stable： the enzyme activity keep about 80% in 70℃ for lh and keep about 80% in pH5.0 - 8.0 for 1 h, even keep about 40% in pill2.0 for 1 h. The enzyme was mainly activated by Mn2＋ and Co2＋ but was mainly restrained by Zn2＋ , Cu2＋and AL3＋.
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2011年第3期13-17,共5页
Food and Fermentation Industries
基金
国家重点基础研究发展计划(973计划)项目(2007CB707805)
关键词
嗜热木糖异构酶
酶的纯化
酶学性质
D-xylose isomerase, enzyme purification, enzyme characterization
