利用谷氨酸棒杆菌转化法合成4–羟基异亮氨酸

Synthesis of 4-hydroxyisoleucine with Corynebacterium glutamicum via Biotransformation

4–羟基异亮氨酸(4-hydroxyisoleucine,4-HIL)具有葡萄糖依赖的促进胰岛素分泌的活性,在L–异亮氨酸(Lisoleucine,L-Ile)生产菌株谷氨酸棒状杆菌(Corynebacterium glutamicum)YILW中过表达来源于苏云金芽胞杆菌(Bacillus thuringiensis)TCCC11826的L–异亮氨酸羟化酶(L-isoleucine dioxygenase,IDO)编码基因ido,以期利用微生物转化法合成4-HIL,并研究α–酮戊二酸(α-ketoglutarate,α-KG)和Fe2+添加量对菌株合成4-HIL的影响.结果表明:构建的C.glutamicum YILW-IDO菌株能够表达出有活性的IDO,并能够利用菌体自身合成的L-Ile以及培养基中的α–酮戊二酸合成4-HIL.此外,α–酮戊二酸和Fe2+均能影响4-HIL的合成,在其添加量分别为40,mmol/L和4,mmol/L条件下,培养50,h,4-HIL产量达(35.7±1.0)mmol/L.本研究可为4-HIL及氨基酸衍生物的生物制造提供理论依据.

4-hydroxyisoleucine（4-HIL）possesses glucose-dependent insulinotropic activities.L-isoleucine dioxygenaseencoded gene ido from Bacillus thuringiensis TCCC11826 was cloned and expressed in L-isoleucine produced strain Corynebacterium glutamicum YILW to synthesize 4-hydroxyisoleucine via biotransformation.The effect of α-ketoglutarate（α-KG）and Fe2＋ on 4-HIL synthesis was also studied.C.glutamicum YILW-IDO expressed active IDO was constructed,whichcould directly convert its endogenous L-isoleucine and α-ketoglutarate in the medium into 4-HIL.Moreover,4-HIL synthesiscould be affected by α-KG and Fe2＋.After 50,h fermentation,（35.7±1.0）mmol/L 4-HIL was produced by adding40,mmol/L α-KG and 4,mmol/L Fe2＋.This research can lay a theoretical foundation for the microbial manufacture technologyof 4-HIL and amino acid derivatives.