酶法合成L-丝氨酸及反应液中氨基酸的分离

Enzymatic Production of L Serine and Separation of Amino Acids from Reaction Solution

含 gly A的基因工程菌所表达的 SHMT可催化甲醛和甘氨酸特异地合成 L-丝氨酸。对酶法合成的部分条件进行了优化 ,并根据甲醛滴定的原理 ,确定了通过检测 p H变化控制甲醛流加速度的方案 ,最终的反应液中 L-丝氨酸浓度达 0 .2 mol/L。反应结束后的酶反应液中同时含有甘氨酸和丝氨酸 ,利用国产 71 7树脂获得较为理想的分离效果 ,丝氨酸的收率达 77% 。

Serine hydromethyltransferase (SHMT) expressed by genetic engineered bacteria can synthesize L serine from HCHO and glycine. Some reaction conditions were optimized. Based on the principle of HCHO titration, the feed rate of HCHO solution was controlled in response to the medium of pH. The concentration of L Ser reached about 0.2 mol/L in the obtained reaction solution. L Ser and glycine was separated from reaction solution by column chromatography of Resin 717. The separation result was satisfactory and the yield of L Ser was 77%. There was no glycine in the product of L serine.