Production of optically pure D-lactic acid in mineral salts medium by metabolically engineered Escherichia coli W3110.

ABSTRACT: The resistance of polylactide to biodegradation and the physical properties of this polymer can be controlled by adjusting the ratio of L-lactic acid to D-lactic acid. Although the largest demand is for the L enantiomer, substantial amounts of both enantiomers are required for bioplastics. We constructed derivatives of Escherichia coli W3110 (prototrophic) as new biocatalysts for the production of D-lactic acid. These strains (SZ40, SZ58, and SZ63) require only mineral salts as nutrients and lack all plasmids and antibiotic resistance genes used during construction. D-Lactic acid production by these new strains approached the theoretical maximum yield of two molecules per glucose molecule. The chemical purity of this D-lactic acid was approximately 98% with respect to soluble organic compo

SUBMITTER: Zhou S 

PROVIDER: S-EPMC152430 | biostudies-literature | 2003 Jan

REPOSITORIES: biostudies-literature