摘要
筛选到1株菊粉酶高产克鲁维酵母菌株,采用酵母高密度细胞发酵方法,最高菊粉酶产量达到28878u/mL,比80～90年代国际上报道的克鲁维酵母菊粉酶最高产量高68倍。该酶的菊粉酶/转化酶活性比为1/2472;菊糖Km=133mmol/L,蔗糖Km=626mmol/L;最适反应pH值为44,但在pH38～56的范围内均保持了较高的活性,相当于最适pH值下活性的90%;最适反应温度为55℃,在50～575℃范围内能够保持较高活性,50℃下酶的半衰期约为16h;外加Mg2+提高酶活性1128%。
A yeast strain Kluyveromyces with high inulinase yield was screened.The highest inulinase activity of 288 78u/mL was reached when a high cell density cultivation method was developed for inulinase production.It was 6 8 times higher than the highest level reported in the same species.The activity ratio of its inulinase to invertase was 1/24 72 ,the K m values were 13 3mmol/L and 62 6mmol/L when inulin and sucrose were used as substrate,respectively;The optimum pH value was 4 4,this enzyme also showed a good pH adaptability and stability,i.e.more 90% of the highest level was maintained between pH 3 8 and 5 6;The optimum reaction temperature was 55℃,higher activity was maintained between 50～57 5℃,its half life period was 16 hours at 55℃;It was found for the first time that addition of magnesium ion into the reaction system increased the enzyme activity by 11%.
出处
《生物工程学报》
CAS
CSCD
北大核心
2000年第1期60-64,共5页
Chinese Journal of Biotechnology
基金
国家自然科学基金项目!( 3 9970 5 49)
中国农业科学院重点课题项目!"一步法制备高果糖浆工程研究"( 990 3 6 )
关键词
克鲁维酵母
菊粉酶
酶学性质
高果糖浆
发酵
Kluyveromyces, inulinase,high density cell cultivation,enzymology property,high fructose syprus
