酪氨酸酚裂解酶的固定化与转化条件的优化

以欧文氏菌(Erwinia herbicola)来源的酪氨酸酚裂解酶的重组大肠埃希菌Escherichia coli BL21为研究对象,研究固定化大肠埃希菌生产L-酪氨酸的条件。以海藻酸钠为载体,采用单因素实验分别考察了载体材料、明胶浓度、反应时间、苯酚浓度和辅助剂(二氧化硅、硅藻土和碳酸钙)等因素对L-酪氨酸生产的影响,发现明胶浓度、反应时间、苯酚和碳酸钙等因素的影响较为显著,进而通过正交实验探索最优条件。结果表明,生产L-酪氨酸的最优条件:载体为4%海藻酸钠与6%明胶的混合载体,苯酚浓度0.08 mol/L,反应时间8 h,于载体中添加0.6%碳酸钙。此条件下,连续反应9次后L-酪氨酸的产量达到64.5 g/L,比优化前提高了451.3%。

Optimization of Immobilization and Transformation Conditions for Tyrosine Phenol Lyase

In this study, a recombined E. coli BL21 carrying tyrosine phenol lyase derived from Erwinia herbicola was used as a research object to study the conditions for L-tyrosine production by immobilizing E. coli. Using sodium alginate as carrier, the effects of the gelatin concentration, reaction time, gelatin and adjuvant (silicon dioxide, diatomaceous earth and calcium carbonate) on L tyrosine production were investigated respectively adopting single factor experiment, it was found that the effects of gelatin concentration, reaction time, the phenol concentration and calcium carbonate and other factors were comparatively significant. Then the optimal conditions were explored by orthogonal experiments. The results showed that the most optimal L-tyrosine production conditions were 4% sodium alginate and 6% gelatin as mixed carrier, 0.08 mol/L phenol, 8 hours reaction time, and 0.6% calcium carbonate added to the carrier, under these conditions the output of L-tyrosine was at 64.5 g/L after 9 consecutive reactions, increased by 451.3% higher than that before optimization.