Abstract: The effects of nutritional and environmental conditions on production of tyrosine phenol lyase (TPL) were investigated in flask and 4 L fermentor. The optimal concentrations of glucose and corn steep liquor for recombinant strain growth and TPL production were 20 g/L and 1.0 g/L, respectively. When the level of dissolved oxygen was kept at 30%, a high cell concentration and TPL activity reached 4.78 g/L and 52.8 U/g (DCW), which were 21% and 36.1% higher than those without dissolved oxygen control, respectively. The cell concentration reached 31.5 g/L when the strategies of dissolved oxygen feedback regulation and restrictive supplement of nutrients were used. By using a bi-stage pH and temperature control strategy, in which pH value and temperature were controlled at 7.0 and 37℃ in the first 8 h and then switched to pH 8.0 and 30℃, a high cell concentration and high TPL activity [154.4 U/g (DCW)] were achieved.

Key words: E. coli M15 (pQTPL), tyrosine phenol lyase, high-efficiency production

摘要： 在摇瓶和4 L发酵罐上研究了营养和环境条件对重组菌E. coli M15 (pQTPL)分批发酵生产酪氨酸酚裂解酶(TPL)的影响. 在培养基中添加20 g/L葡萄糖和1.0 g/L玉米浆使TPL酶活提高到63.1 U/g(干重). 在此基础上，维持发酵液中溶氧水平为30%，可使菌体浓度在8 h达到4.78 g/L，酶活为54.6 U/g，比对照组(不控制溶氧)分别提高了21%和31.6%. 采用溶氧反馈调节-限制性补料策略，可使菌体浓度提高到31.5 g/L. 采用两阶段温度和pH控制策略，在发酵前8 h控制pH 7.0、温度37℃，8 h 至发酵结束之间控制pH为8.0、温度为30℃，可使重组菌的TPL酶活达到154.4 U/g，并使TPL在细胞中过量表达，实现了高菌体浓度和高TPL酶活的统一.

关键词: E. coli M15 (pQTPL), 酪氨酸酚裂解酶, 高效生产