Application of NAD-dependent polyol dehydrogenases for enzymatic mannitol/sorbitol production with coenzyme regeneration.
D-Mannitol and D-sorbitol were produced enzymatically from D-fructose using NAD-dependent polyol dehydrogenases. For the production of D-mannitol the Leuconostoc mesenteroides mannitol dehydrogenase could be used. Gluconobacter oxydans cell extract contained however both mannitol and sorbitol dehydrogenase. When this cell extract was used, the reduction of D-fructose resulted in a mixture of D-sorbitol and D-mannitol. To determine the optimal bioconversion conditions the polyol dehydrogenases were characterized towards pH- and temperature-optimum and -stability. As a compromise between enzyme activity and stability, the bioconversion reactions were performed at pH 6.5 and 25 degrees C. Since the polyol dehydrogenases are NADH-dependent, an efficient coenzyme regeneration was needed. Regeneration of NADH was accomplished by formate dehydrogenase-mediated oxidation of formate into CO2.
Department of biochemical and microbial technology, Ghent University, Coupure links 653, B-9000 Ghent, Belgium.
S
S
Parmentier
F
F
Arnaut
W
W
Soetaert
E J
EJ
Vandamme
D003470:Culture Media; D005632:Fructose / Q000378:metabolism; D007700:Kinetics; D007064:L-Iditol 2-Dehydrogenase / Q000378:metabolism*; D007934:Leuconostoc / Q000201:enzymology / Q000254:growth & development; D008353:Mannitol / Q000378:metabolism*; D008354:Mannitol Dehydrogenases / Q000378:metabolism; D009243:NAD / Q000378:metabolism*; D010084:Oxidation-Reduction; D013012:Sorbitol / Q000378:metabolism*; D013816:Thermodynamics
D003470:Culture Media; D009243:NAD; D005632:Fructose; D008353:Mannitol; D013012:Sorbitol; D008354:Mannitol Dehydrogenases; D007064:L-Iditol 2-Dehydrogenase