[Enzymatic synthesis of L-malic acid from fumaric acid using immobilized Escherichia coli cells].

Optimal conditions were chosen for cultivation of Escherichia coli 85 cells with a rather high fumarate-hydratase activity on a cheap medium containing no edible raw material. An active biocatalyst for the synthesis of L-malic acid from fumaric acid was obtained based on E. coli 85 cells immobilized in carrageenan. The enzymatic synthesis of L-malic acid from potassium fumarate was kinetically studied and optimized. Some thermodynamic parameters of fumaric acid hydration into malic acid were determined. A technique for assaying the reaction mixture was developed that involved high performance liquid chromatography.