{Reference Type}: Journal Article
{Title}: Combinatorial protein engineering and transporter engineering for efficient synthesis of L-Carnosine in Escherichia coli.
{Author}: Liu Y;Pan X;Zhang H;Zhao Z;Teng Z;Rao Z;
{Journal}: Bioresour Technol
{Volume}: 387
{Issue}: 0
{Year}: 2023 Nov 6
{Factor}: 11.889
{DOI}: 10.1016/j.biortech.2023.129628
{Abstract}: L-Carnosine has various physiological functions and is widely used in cosmetics, medicine, food additives, and other fields. However, the yield of L-Carnosine obtained by biological methods is far from the level of industrial production. Herein, a cell factory for efficient synthesis of L-Carnosine was constructed based on transporter engineering and protein engineering. Firstly, a dipeptidase (SmpepD) was screened from Serratia marcescens through genome mining to construct a cell factory for synthesizing L-Carnosine. Subsequently, through rationally designed SmPepD, a double mutant T168S/G148D increased the L-Carnosine yield by 41.6% was obtained. Then, yeaS, a gene encoding the exporter of L-histidine, was deleted to further increase the production of L-Carnosine. Finally, L-Carnosine was produced by one-pot biotransformation in a 5 L bioreactor under optimized conditions with a yield of 133.2 mM. This study represented the highest yield of L-Carnosine synthesized in microorganisms and provided a biosynthetic pathway for the industrial production of L-Carnosine.