葡萄糖供应速率对大肠杆菌表达及分泌人表皮生长因子的影响  

Influence of Specific Glucose Provision Rate on the Expression and Secretion of Human Epidermal Growth Factor in Escherichia coli

作　　者：张海毅[1] 李志敏[1] 钱悦[2] 张倩[2] 甘人宝[2] 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 [2]中国科学院上海生命科学研究院生物化学与细胞生物学研究所,上海200230

出　　处：《华东理工大学学报（自然科学版）》2006年第12期1404-1408,共5页Journal of East China University of Science and Technology

基　　金：863资助项目(2002AA217021)

摘　　要：采用一株大肠杆菌BL 21(DE 3)[pBLMVL 2EGF]生产人表皮生长因子(hEGF),其中hEGF表达由PL启动子控制并通过phoA信号肽分泌到胞外。实验结果表明:诱导阶段以恒定比供应速率流加葡萄糖时,流加速率对hEGF的表达和分泌有很大影响。当葡萄糖比供应速率为0.122g/(g.h)时,hEGF表达水平最低,分泌效率最差,只有37.5%;随着葡萄糖比供应速率的增加,胞外和胞内hEGF比生产速率明显增加,当葡萄糖比供应速率为0.196 g/(g.h)时,单位菌体产生的hEGF水平最高(121.6 m g/g),其中分泌至胞外的hEGF占42%。此外,诱导前补充有机氮源有利于提高诱导初始hEGF的生产速率。A recombinant strain, Escherichia coli BL21 （DE3）[pBLMVL2EGF], was used for the secretory production of human epidermal growth factor （hEGF）. The expression of the gene coding for hEGF, which was inserted behind the phoA signal sequence, was under the control of PL promoter. During the expression phase, glucose was added at constant specific provision rates, which had a great influence on the production and secretion of hEGF. When fed with glucose at a specific provision rate of 0. 122 g/ （g · h）, the hEGF production level was the lowest, and only 37.5% of the produced hEGF was secreted. With the increase of specific glucose provision rate, the specific productivities of extra- and intra-cellular hEGF were enhanced significantly. The highest total hEGF production per biomass was 121.6 mg/g with a specific glucose provision rate of 0. 196 g/（g · h）, and the extracellular hEGF accounted for about 42% of the total hEGF produced. The preinduction nutrient condition had a profound influence on hEGF production; supplementation of complex nitrogen sources greatly improved the initial production rate of hEGF.

关 键 词：人表皮生长因子 PL启动子 分泌 大肠杆菌 

分 类 号：TQ92[轻工技术与工程—发酵工程]