固定化Gibberella intermedia转化3-氰基吡啶制备烟酸  

Biotransformation of 3-cyanopyridine for producing nicotinic acid by immobilized Gibberella intermedia

作　　者：杨涛[1] 李恒[1] 龚劲松[1] 熊雷[1] 朱小燕[1] 许正宏[1] 史劲松[1] 

机构地区：[1]江南大学药学院,江苏无锡214122

出　　处：《化工进展》2014年第9期2432-2437,共6页Chemical Industry and Engineering Progress

基　　金：国家高技术研究发展计划(2012AA022204C);国家自然基金(21206055);江苏省自然科学基金(BK2012127)项目

摘　　要：研究不同复合包埋材料对含腈水解酶的Gibberella intermedia CA3-1进行固定化,选择出最为适合的壳聚糖-聚乙烯醇作为复合包埋材料,其优化后的浓度分别为1.6%和2%。实验结果表明该固定化细胞的最适转化条件为:3-氰基吡啶初始浓度300mmol/L,转化温度30℃,pH值7.0,转化时间60min。固定化细胞可以稳定进行26个批次转化,每克干细胞可转化产生283.5g烟酸,为游离细胞的3倍。此外,固定化细胞对高浓度3-氰基吡啶的耐受性大幅提高,温度稳定性有一定增强。连续补料19次,固定化细胞酶活保留约30%,经折算产率为每克干细胞转化生成191.3g烟酸。Nicotinic acid biotransformation by immobilized Gibberella intermedia CA3-1 harboring nitrilase was investigated in this study. Chitosan-polyvinyl alcohol was found to exhibit great advantages over other composite materials,with contents of chitosan and polyvinyl alcohol 1.6%and 2%,respectively. The experimental results showed that the optimal transformation conditions were as follows：initial 3-cyanopyridine concentrations of 300mmol/L,transformation temperature of 30℃ and initial pH of 7.0. The substrate could be completely converted within 60min. Immobilized cells could be reused for up to 26 batches as compared to 9 batches for free cells. And 283.5g nicotinic acid/（g dcw） was produced with 80.55% enzyme activity preserved. Its transformation capability was three times higher than that of free cells. In addition,the immobilization substantially enhanced its tolerance toward high 3-cyanopyridine concentration and improved its thermalstability. Immobilized cells could biosynthesize 191.3g nicotinic acid/（g dcw）,retaining 30%enzyme activity by 19 fed-batches.

关 键 词：烟酸 G.intermedia CA3-1 固定化 生物催化 稳定性 

分 类 号：Q814.9[生物学—生物工程]