重组大肠杆菌生产类人胶原蛋白Ⅱ的发酵pH优化  

Optimal Strategy of pH Control in the Production of HLCⅡ by Recombinant Escherichia coli

作　　者：王维卓[1,2] 范代娣[1,2,3] 骆艳娥[1,2,3] 马晓轩[1,2,3] 朱晨辉[1,2,3] 郭佳庆[1,2] 

机构地区：[1]西北大学化工学院 [2]陕西省生物材料与发酵工程技术研究中心 [3]陕西省可降解生物医用材料重点实验室,陕西西安710069

出　　处：《陕西师范大学学报（自然科学版）》2010年第5期72-76,共5页Journal of Shaanxi Normal University：Natural Science Edition

基　　金：国家"863"计划基金资助项目(2006AA02Z246;2007AA03Z456);国家自然科学基金资助项目(20776119);陕西省教育厅科学研究发展计划基金资助项目(07JK417)

摘　　要：为了实现类人胶原蛋白（HLCⅡ）的规模化生产,对重组大肠杆菌BL21 3.7在30 L发酵罐中发酵生产类人胶原蛋白Ⅱ过程中的关键参数pH进行了系统的研究.将发酵过程中pH控制在6.0~7.8之间,监测pH对细胞生长以及类人胶原蛋白Ⅱ的产量的影响,从而确定出合理的pH控制策略增加类人胶原蛋白Ⅱ的产量.由实验数据可得,在pH7.5条件下细胞浓度达到最大,为68.5 g/L,但HCLⅡ的浓度为8.5 g/L.在pH6.8条件下,HLCⅡ浓度达到最大,为10.5 g/L,但其细胞浓度只有60.9 g/L.同时,对发酵过程中代谢副产物有机酸的含量也进行了监测,随着发酵过程pH值的升高,总有机酸的量也相应的增加,当发酵过程pH控制在7.8时,总有机酸达到最大,为15.61 g/L.为了提高目标产物的产量,采用pH两阶段控制策略控制发酵,最终类人胶原蛋白Ⅱ浓度可达到11.3 g/L,较恒pH条件下提高了7.61%.To achieve large-scale production of HLC Ⅱ,the key parameter pH in production process of human-like collagen by recombinant Escherichia coli BL21 3.7 was systematicly investigated in a 30 L fermentation tank with triplex turbine impeller.The effect of pH ranging from 6.0 to 7.8 on cell content and HLC Ⅱ production during fermentation process was studied,and an optimal pH strategy was determined for increase of HLC Ⅱ yield.From experimental data,the cell growth and collagen synthesis were significantly affected by pH.An optimal pH of 7.5 for cell growth was obtained with cell density at 68.5 g/L,the concentration of HLC Ⅱ was 8.5 g/L;while an optimal pH of 6.8 for HLC Ⅱ accumulation was obtained with concentration of HLC Ⅱ at 10.5 g/L,and cell density was 60.9 g/L.Additionally,the total organic acid of fermentation process was monitored.The concentration of organic acid increased with pH,and the highest concentration of organic acid,15.61 g/L,was observed when pH was kept constant at 7.8 during the process of fermentation.Based on the results,a pH shift method was developed to gain higher concentration of HCL Ⅱ which reached to 11.3 g/L,increased by 7.61% as compared with constant pH fermentation.

关 键 词：类人胶原蛋白Ⅱ 重组大肠杆菌 pH两阶段控制 有机酸 

分 类 号：TQ929[轻工技术与工程—发酵工程]