谷氨酸棒杆菌脂肪酸合成酶fasA基因的异源表达 对脂肪酸合成的影响Effect of heterologous expression of fasA gene of Corynebacterium glutamicum fatty acid synthase on fatty acid synthesis

Abstract

旨在为脂肪酸高产菌株的筛选和构建奠定理论基础，研究谷氨酸棒杆菌脂肪酸合成酶A（FasA）对大肠杆菌脂肪酸合成的影响，利用生物信息学软件预测分析了FasA的性质并构建过表达载体pXMJ19-fasA，转化至大肠杆菌进行表达,对表达诱导剂异丙基-β-D-硫代吡喃半乳糖苷（IPTG）浓度进行考察，并测定了异源表达后的脂肪酸组成。结果表明，重组菌株在IPTG浓度为1 mmol/L下诱导20 h，棕榈油酸和油酸产量分别达到1.735、2.325 mg/g，与对照菌株相比分别提高了53.95%和59.68%。研究结果说明FasA对大肠杆菌合成棕榈油酸和油酸有促进作用。 In order to lay a theoretical foundation for screening and constructing fatty acid high-yielding strains, the effects of Corynebacterium glutamicum fatty acid synthase A (FasA) on the synthesis of fatty acids in E. coli were studied, the properties of FasA were predicted and analyzed using bioinformatics software, moreover the overexpression vector pXMJ19-fasA was constructed and transformed into E. coli for expression, the concentration of expression inducer isopropyl-β-D-thiogalactoside (IPTG) was investigated and the fatty acid composition after heterologous expression was determined.The results showed that when the recombinant strain was induced under the IPTG concentration of 1 mmol/L for 20 h，the yield of palmitoleic acid and oleic acid reached 1.735，2.325 mg/g ，which increased by 53.95% and 59.68% respectively compared with the control strain. These results indicate that FasA can promote the synthesis of palmitoleic acid and oleic acid by E. coli.

Keywords

• 脂肪酸合成酶；谷氨酸棒杆菌;棕榈油酸；油酸；异源表达
• fatty acid synthase；corynebacterium glutamicum；palmitoleic acid；oleic acid；heterologous expression