中文摘要：

XT11菌种经过发酵能够产生黄原胶液化酶,该酶能够分解黄原胶生成寡糖。实验结果说明,黄原胶液化酶的最适温度为40℃,以磷酸盐缓冲液为最佳缓冲液的酶反应的最适pH值为6.0;酶反应最适底物质量浓度为3 g/L,Km=1.68,Vmax=0.203 7 g.mL-1·min^-1。Ca^2＋在浓度较低时对黄原胶液化酶有激活作用,而其他离子在10和30 mmol/L时对黄原胶液化酶有不同程度的抑制作用,并且Fe^3＋和Cr^3＋的抑制作用表现最为突出。

英文摘要：

Microbacterium sp. XT11 produces xanthan-liquefying enzyme that can degrade xanthan to oligosaccharide. The xanthan-liquefying enzyme was characterized after partial purification. The opti-mal reaction condition is. 40 C, pH 6.0, xanthan concentration 3 g/L. The Km is 1.68, the Vmax is 0. 203 7 g · mL^-1 . min^- 1. Its activity is activated by Ca^2＋ but inhibited by almost other metal-ions at 10 and 30 mmol/L. Especially, the ions of Fe^3＋ and Cr^3＋ show the strongest inhibition on xanthan-liquefying.