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

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.