化工进展

• 生物与医药化工 • 上一篇    下一篇

固定化Gibberella intermedia转化3-氰基吡啶制备烟酸

杨涛,李恒,龚劲松,熊雷,朱小燕,许正宏,史劲松   

  1. 江南大学药学院,江苏 无锡 214122
  • 出版日期:2014-09-05 发布日期:2014-09-05

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

YANG Tao,LI Heng,GONG Jinsong,XIONG Lei,ZHU Xiaoyan,XU Zhenghong,SHI Jinsong   

  1. School of Pharmaceutical Science,Jiangnan University,Wuxi 214122,Jiangsu,China
  • Online:2014-09-05 Published:2014-09-05

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。

关键词: 烟酸, G. intermedia CA3-1, 固定化, 生物催化, 稳定性

Abstract: 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.

Key words: nicotinic acid, G. intermedia CA3-1, immobilization, biocatalysis, stability

京ICP备12046843号-2;京公网安备 11010102001994号
版权所有 © 《化工进展》编辑部
地址:北京市东城区青年湖南街13号 邮编:100011
电子信箱:hgjz@cip.com.cn
本系统由北京玛格泰克科技发展有限公司设计开发 技术支持:support@magtech.com.cn