Mutyala Sakuntala, Li Shuwei, Khandelwal Himanshu, Kong Da Seul, Kim Jung Rae
School of Chemical Engineering, Pusan National University, Busan 46241, Republic of Korea.
ACS Omega. 2023 Jul 17;8(29):26231-26242. doi: 10.1021/acsomega.3c02520. eCollection 2023 Jul 25.
Acetate is an end-product of anaerobic biodegradation and one of the major metabolites of microbial fermentation and lingo-cellulosic hydrolysate. Recently, acetate has been highlighted as a feedstock to produce value-added chemicals. This study examined acetate conversion to succinate by citrate synthase ()-overexpressed under microaerobic conditions. The acetate metabolism is initiated with the gltA enzyme, which converts acetyl-CoA to citrate. -overexpressing (-KT) showed an ∼50% improvement in succinate production compared to the wild type. Under the optimal pH of 7.5, the accumulation of succinate (4.73 ± 0.6 mM in 36 h) was ∼400% higher than that of the wild type. Overall, overexpression alone resulted in 9.5% of the maximum theoretical yield in a minimal medium with acetate as the sole carbon source. This result shows that citrate synthase is important in acetate conversion to succinate by under microaerobic conditions.
乙酸盐是厌氧生物降解的终产物，也是微生物发酵和木质纤维素水解产物的主要代谢物之一。最近，乙酸盐已被视为生产增值化学品的原料。本研究考察了在微需氧条件下柠檬酸合酶（）过表达的菌株将乙酸盐转化为琥珀酸盐的情况。乙酸盐代谢由gltA酶启动，该酶将乙酰辅酶A转化为柠檬酸。与野生型相比，过表达柠檬酸合酶的菌株（-KT）琥珀酸盐产量提高了约50%。在最适pH值7.5条件下，琥珀酸盐的积累量（36小时内为4.73±0.6 mM）比野生型高约400%。总体而言，在以乙酸盐作为唯一碳源的基本培养基中，仅柠檬酸合酶过表达就达到了最大理论产量的9.5%。该结果表明，在微需氧条件下，柠檬酸合酶对于菌株将乙酸盐转化为琥珀酸盐具有重要作用。
