卡拉胶固定化Nocardia sp.生产L(+)酒石酸  

Production of L(+)Tartaric Acid by Immobilized Nocardia sp.Cells with Carrageenan

作　　者：柯昌武[1] 蔡水洪[1] 叶勤[1] 

机构地区：[1]华东理工大学生物反应器工程国家重点实验室,上海200237

出　　处：《华东理工大学学报（自然科学版）》2006年第11期1270-1274,共5页Journal of East China University of Science and Technology

基　　金：上海市科委资助项目(03DZ19207)

摘　　要：采用卡拉胶包埋具有环氧琥珀酸水解酶活性的诺卡氏菌菌体用于生产酒石酸。固定化的最适卡拉胶浓度为20 g/L,菌体浓度为200 g/L,交联剂戊二醛浓度为5 g/L,固定化后的酶活回收率可以达到70%。高浓度的环氧琥珀酸对水解反应产生抑制作用,游离细胞的米氏常数(Km)为0.234 m o l/L,抑制常数(KI)为0.22 m o l/L,固定化细胞则分别为0.31 m o l/L和0.21 m o l/L。游离细胞和固定化细胞反应的最适pH分别为8.0和8.5。细胞固定化以后,耐热稳定性增强。30°C 0.2m o l/L的底物浓度下,摇瓶中连续转化25批,L(+)酒石酸的转化率接近100%。Nocardia cells possessing epoxysuccinate hydrase activity immobilized with k-carrageenan was used to produce L（＋）tartaric acid. Immobilized Nocardia cells retained highest apparent epoxysuccinate hydrase activity at a gel concentration of 20 g/L and a wet cell concentration of 200 g/L. A cross-linking reagent, glutaraldehye, was used at a concentration of 5 g/L to enhance the intensity of the gel. The recovery of the apparent residual epoxysuccinate hydrase activity in immobilized cells achieved 70% under the above conditions. High concentration of epoxysuccinate was found to inhibit the hydrolysis reaction. The inhibition constant and Km for the free Nocardia cells were 0.22 mol/L and 0. 234 mol/L respectively, while those for the immobilized cells were 0.21 mol/L and 0.31 mol/L. The optimum pH for the hydrolysis reaction with immobilized cells was 8.5, while it was 8.0 with free cells. Immobilized cells had better thermostability and could be used in repeated batch transformation for 25 times without obvious loss of activity when the initial epoxysuccinate concentration was 0.2 mol/L.

关 键 词：L(+)酒石酸 诺卡氏茼 环氧琥珀酸水解酶 固定化 卡拉胶 

分 类 号：TQ920.6[轻工技术与工程—发酵工程]