Overcoming NADPH product inhibition improves D-sorbitol conversion to L-sorbose.

ABSTRACT: Gluconobacter oxydans sorbitol dehydrogenase (GoSLDH) exhibits a higher catalytic efficiency than other L-sorbose producing enzymes. During the reaction catalysed by GoSLDH, NADP⁺ is reduced to NADPH and D-sorbitol is oxidized to L-sorbose. However, GoSLDH activity is inhibited by the NADPH (K_i = 100 μM) formed during the enzymatic reaction. Therefore, Escherichia coli_{gosldh-lrenox} producing both GoSLDH for D-sorbitol oxidation and LreNOX (NAD(P)H oxidase from Lactobacillus reuteri) for NADP⁺ regeneration was generated and used for L-sorbose production. Whole cell biocatalysts with the LreNOX cofactor recycling system showed a high conversion rate (92%) of D-sorbitol to L-sorbose in the presence of low concentration of NADP⁺ (0.5 mM).

SUBMITTER: Kim TS 

PROVIDER: S-EPMC6349845 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature