反应分离耦合酶法制备D-苹果酸

用Pimelobacter simplex DM18菌的马来酸水合酶高效转化马来酸制备D-苹果酸。为避免高浓度产物及底物对水合酶的抑制作用,利用马来酸和D-苹果酸的钙盐溶解度低的特点,以马来酸钙为底物,经水合酶催化加水转化成D-苹果酸钙,实现边反应边分离产物的反应分离耦合,同时利用钙盐和钠盐的混合反应体系提高了转化反应速率,反应36 h,可制备386g/L的D-苹果酸钙盐,相当于300 g／L D-苹果酸,转化率接近99％,光学纯度达97.03％。

Malease-catalyzed production of D-malate by coupling reaction and separation

Maleate hydratase from Pimelobacter simplex DM18 was used to effectively produce D-inalate from maleate.To avoid the inhibition of the hydratase from product and substrate of high concentrations, calcium-hgand complex was used in this reaction system,because of the low solubility of Ca-maleate and Ca-malate. Ca-maleate as a substrate was conversed into Ca malate by maleate hydratase through coupling reaction and separation, and high biocatalyst velocity was maintained during the process by regulating the ratio of the complex maleate to free maleate. After 36 h of reaction,385 g/L of Ca-D-malate was produced.This is equivalent to 300 g/L of D-malic acid,with a 99% mol yield,and 97.03% in optical purity.