L-phenylglycine(L-phg)is a valuable non-proteinogenic amino acid used as a precursor to β-lactam antibiotics,antitumor agent taxol and many other pharmaceuticals.L-phg synthesis through microbial bioconversion allows...L-phenylglycine(L-phg)is a valuable non-proteinogenic amino acid used as a precursor to β-lactam antibiotics,antitumor agent taxol and many other pharmaceuticals.L-phg synthesis through microbial bioconversion allows for high enantioselectivity and sustainable production,which will be of great commercial and environmental value compared with organic synthesis methods.In this work,an L-phg synthesis pathway was built in Escher-ichia coli resulting in 0.23 mM L-phg production from 10 mM L-phenylalanine.Then,new hydroxymandelate synthases and hydroxymandelate oxidases were applied in the L-phg synthesis leading to a 5-fold increase in L-phg production.To address 2-oxoglutarate,NH_(4)^(+),and NADH shortage,a cofactor self-sufficient system was introduced,which converted by-product L-glutamate and NAD^(+)to these three cofactors simultaneously.In this way,L-phg increased 2.5-fold to 2.82 mM.Additionally,in order to reduce the loss of these three cofactors,a protein scaffold between synthesis pathway and cofactor regeneration modular was built,which further improved the L-phg production to 3.72 mM with a yield of 0.34 g/g L-phe.This work illustrated a strategy applying for whole-cell biocatalyst converting amino acid to its value-added chiral amine in a cofactor self-sufficient manner.展开更多
基金the National Natural Science Foundation of China(Project No.31900064)as well as the Natural Science Foundation of Heilongjiang Province of China(Project No.LH2019C012)。
文摘L-phenylglycine(L-phg)is a valuable non-proteinogenic amino acid used as a precursor to β-lactam antibiotics,antitumor agent taxol and many other pharmaceuticals.L-phg synthesis through microbial bioconversion allows for high enantioselectivity and sustainable production,which will be of great commercial and environmental value compared with organic synthesis methods.In this work,an L-phg synthesis pathway was built in Escher-ichia coli resulting in 0.23 mM L-phg production from 10 mM L-phenylalanine.Then,new hydroxymandelate synthases and hydroxymandelate oxidases were applied in the L-phg synthesis leading to a 5-fold increase in L-phg production.To address 2-oxoglutarate,NH_(4)^(+),and NADH shortage,a cofactor self-sufficient system was introduced,which converted by-product L-glutamate and NAD^(+)to these three cofactors simultaneously.In this way,L-phg increased 2.5-fold to 2.82 mM.Additionally,in order to reduce the loss of these three cofactors,a protein scaffold between synthesis pathway and cofactor regeneration modular was built,which further improved the L-phg production to 3.72 mM with a yield of 0.34 g/g L-phe.This work illustrated a strategy applying for whole-cell biocatalyst converting amino acid to its value-added chiral amine in a cofactor self-sufficient manner.
