产腈水合酶菌株的驯化及其产酶条件优化研究

以Nocardia sp LNSY06为出发菌株,通过逐渐增加培养基中丙烯腈的浓度重复继代培养,得到1株酶活为62.5U/mg的腈水合酶高活力菌株,酶活比出发菌株提高了15倍。研究结果表明:驯化的最优条件为:葡萄糖为20g/L,诱导剂脲为0.06g/L,Co2+为0.3g/L,丙烯酰胺为10%,反应pH为7,温度为28℃,底物丙烯腈体积分数<4%,产物丙烯酰胺的质量分数<20%。

STUDY ON DOMESTICATION OF A NITRILE HYDRATASE PRODUCING STRAIN AND OPTIMIZATION ON ITS NITRILE HYDRATASE PRODUCING CONDITIONS

A bacterial strain having higher nitrile hydratase activity and acrylonitrile concent rationed tolerance,numbered Nocardia sp LNSY06,is developed by repeated subculturing of it in the broth containing acrylonitrile with slightly increased.The specific nitrile hydratase activity of it increased up to 62.5 unit U/mg of dry cells,16 times higher than that of Nocardia sp LNSY06.The results show that the factors influencing nitrle hydratase activity mostly are glucose,urea,acrylon,acrylamide,Co~(2+),pH and temperature etc;The optimum conditions of the best extraction ratio are as follows: glucose 20g/L,urea 0.06g/L,acrylon <4%,acrylamide <20%,Co~(2+) 0.3g/L,pH 7.0 and temperature 28℃.