Production of L-serine by metabolically engineered Escherichia coli
LI Xuan1, WANG Jiachu1, LIU Yining1, JIANG Shuai1, WU Heyun2, XIE Xixian1,3*
1(College of Biotechnology,Tianjin University of Science and Technology,Tianjin 300457,China) 2(College of Food Science and Engineering,Tianjin University of Science and Technology,Tianjin 300457,China) 3(National and Local United Engineering Lab of Metabolic Control Fermentation Technology,Tianjin 300457,China)
Abstract: L-Serine is a neutral amino acid with important physiological functions widely used in food, cosmetics, and medicine industries. Escherichia coli MG1655 was systematically modified by reducing the degradation of L-serine and enhancing the expression synthetases and trans-system to produce L-serine. In particular, Ptrp was used to regulate the expression of serine hydroxymethyl transferase to decrease the degradation pathway of L-serine to glycine. The synthesis of L-serine significantly enhanced. The obtained strain SER09 produced 13.53 g/L of L-serine by shake-flask fermentation after 24 hand 22.31 g/L L-serine in a 5 L fermenter for 28 h. A platform strain producing L-serine was constructed, which has a good application prospect.
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