双酶级联生物合成D-赖氨酸  

Production of D-Lysine Catalyzed by a Two-Step Biocatalytic Cascade of Amino Acid Racemase and Lysine Decarboxylase

作　　者：陆阳[1] 吴四平 张宏娟[2] 刘茜[1] 焦庆才[1] 刘均忠[1] 

机构地区：[1]医药生物技术国家重点实验室南京大学生命科学学院,江苏南京210093 [2]南京医科大学药学院,江苏南京210029

出　　处：《精细化工》2015年第8期873-877,890,共6页Fine Chemicals

基　　金：国家自然科学基金青年科学基金项目(21302100)~~

摘　　要：建立了氨基酸消旋酶和赖氨酸脱羧酶双酶级联高效生产D-赖氨酸的方法。利用氨基酸消旋酶全细胞催化消旋L-赖氨酸得到DL-赖氨酸,去除氨基酸消旋酶后再加入赖氨酸脱羧酶,将消旋产物中的L-构型脱羧生成1,5-戊二胺和CO2,剩下D-赖氨酸;最终,通过阳离子交换树脂吸附洗脱得到D-赖氨酸。经考察双酶级联催化的最佳条件为:反应温度40℃,0.2 mol/L磷酸钾缓冲溶液(p H=5.8),底物L-赖氨酸质量浓度为50 g/L,氨基酸消旋酶全细胞和赖氨酸脱羧酶全细胞质量浓度均为10 g/L,4 mmol/L磷酸吡哆醛,0.1 g/L Triton X-100,反应时间12 h,其中消旋反应2 h和脱羧反应10 h,最终D-赖氨酸收率达42%,对映体过量值(e.e.值)=98%。This study involves the design and investigation of two continuous reaction processes for the efficient production of D-lysine,including an enzymatic racemization step and an enzymatic decarboxylation step. Firstly, L-lysine was racemized to give DL-lysine by whole cells containing amino acid racemase （AAR） ;then eliminating AAR and adding whole cells containing lysine decarboxylase （ LDC ）, L-lysine in the mixture was selectively decarboxylated to give 1,5-pentanediamine and C02; finally D-lysine was separated from mixture by ion exchange resin. An optimal conditions for the cascaded enzyme system are as follows ：reaction temperature 40 ℃ ,0. 2 mol/L of potassium phosphate buffer （pH = 5. 8）,50 g/L of L- lysine,10 g/L whole cells of AAR and LDC ,respectively,4 mmol/L of PLP,and 0. 1 g/L of Triton X- 100. Under such optimal conditions,after 12 h,including 2 h for racemization step and 10 h for deearboxylation step,the enzymatic catalysis reaction was completed, and the yield of D-lysine could reach 42%, with enantiomeric excess（e, e. ） = 98%.

关 键 词：双酶级联催化 氨基酸消旋酶 赖氨酸脱羧酶 D-赖氨酸 生物工程 

分 类 号：Q55[生物学—生物化学]