黄原胶液化酶的反应条件

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。Ca2+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Fe3+和Cr3+的抑制作用表现最为突出。

Characterization of xanthan-liquefying enzyme producedby Microbacterium sp. XT11

Microbacterium sp. XT11 produces xanthan-liquefying enzyme that can degrade xanthan to oligosaccharide.The xanthan-liquefying enzyme was characterized after partial purification.The optimal reaction condition is: 40℃,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 Ca2+ but inhibited by almost other metal-ions at 10 and 30 mmol/L.Especially,the ions of Fe3+ and Cr3+show the strongest inhibition on xanthan-liquefying.