枯草芽孢杆菌产D-阿洛酮糖3-差向异构酶的发酵优化  

Fermentation Optimization of D-Psicose 3-Epimerase Produced by Bacillus subtilis

作　　者：卜一凡 张涛[1,2] 陈静静 江波[1,2] BU Yifan;ZHANG Tao;CHEN Jingjing;JIANG Bo(State Key Laboratory of Food Science and Technology,Jiangnan University,Wuxi 214122,China;International Joint Laboratory on Food Safety,Jiangnan University,Wuxi 214122,China)

机构地区：[1]食品科学与技术国家重点实验室,江南大学,江苏无锡214122 [2]江南大学食品安全国际联合实验室,江苏无锡214122

出　　处：《食品与生物技术学报》2022年第5期74-80,共7页Journal of Food Science and Biotechnology

基　　金：广东省重点领域研发计划项目(2020B020226007)。

摘　　要：D-阿洛酮糖是D-果糖在C-3位的差向异构体,由于较低的热量和与蔗糖相似的甜度,D-阿洛酮糖成为一个具有发展前景的功能性甜味剂。D-阿洛酮糖3-差向异构酶(D-psicose 3-epimerase,EC 5.1.3.30,DPEase)能够催化D-果糖生产D-阿洛酮糖,这种生物酶法制备的功能性甜味剂D-阿洛酮糖由于简单的纯化步骤和高产物浓度等优点受到关注。该研究对1株前期构建的枯草芽孢杆菌Bacillus subtilis 1A751/pUB-P43dpe-dal产DPEase进行了3 L发酵罐水平培养,通过优化溶解氧(DO)、pH、温度、初始碳源质量浓度确定最适发酵条件为:DO为30%、pH 6.0、温度37℃、初始葡萄糖质量浓度15 g/L,最高发酵酶活达78.3 U/mL。在此基础上进行补料发酵优化,得到最适补料条件为:在发酵5 h进行补料,碳源补料速率8.0 g/(L·h),在此条件下,发酵9 h全细胞酶活高达123.0 U/mL。此发酵策略为扩大工业化生产提供了参考。D-allulose is a C-3 epimer of D-fructose.It has similar sweetness to sucrose but provids significantly lower calorie,which makes it a functional sweetener with important application potentials.The enzymatic preparation of D-allulose from D-fructose catalyzed by D-psicose 3-epimerase(EC 5.1.3.30,DPEase)has attracted much attention owing to its simple purification process and high product concentration.To obtain higher expression of enzyme,DPEase was produced by a previously constructed strain,Bacillus subtilis 1A751/pUB-P43dpe-dal,in a 3 L fermentor.By optimizing the dissolved oxygen(DO),pH,temperature and initial carbon source concentration,the optimal fermentation conditions were determined as follows:DO 30%,pH 6.0,37℃,initial glucose concentration of 15 g/L.And the maximum enzyme activity reached 78.3 U/mL.On this basis,the fed-batch fermentation was applied,and the optimal fed fermentation time was 5 h.At a constant feeding rate of 8.0 g/(L·h),the whole-cell enzyme activity reached 123.0 U/mL after 9 h fermentation.This strategy of fermentation could provide a theoretical basis for the expanding the industrial production of D-allulose.

关 键 词：D-阿洛酮糖 D-阿洛酮糖3-差向异构酶 枯草芽孢杆菌 发酵优化 酶活 

分 类 号：TS241[轻工技术与工程—制糖工程]