Novel bioreductions by hyperthermophilic microorganisms for the natural, specific and on-line production of fine chemicals

Informations projet

PYRED

N° de convention de subvention: QLK3-CT-2001-01676

Projet clôturé

Date de début 1 Novembre 2001

Date de fin 31 Octobre 2004

Financé au titre de

• Specific Programme for research, technological development and demonstration on "Quality of life and management of living resources", 1998-2002

Coût total € 2 009 770,00

Contribution de l’UE € 1 550 000,00

Coordonné par

WAGENINGEN UNIVERSITY
Netherlands

Livrables

Publication on novel bioreductions by hyperthermophilic microorganisms for the natural, specific and on-line production of fine chemicals

The gene encoding a novel alcohol dehydrogenase that belongs to the aldo-keto reductase superfamily has been identified in the hyperthermophilic archaeon Pyrococcus furiosus. The gene, referred to as adhD, was functionally expressed in Escherichia coli and subsequently purified to homogeneity. The enzyme has a monomeric conformation with a molecular mass of 32 kDa. The catalytic activity of the enzyme increases up to 100°C, and a half-life value of 130 min at this temperature indicates its high thermostability. AdhD exhibits broad substrate specificity with, in general, a preference for the reduction of ketones (pH optimum, 6.1) and the oxidation of secondary alcohols (pH optimum, 8.8). Maximal specific activities were detected with 2,3-butanediol (108.3 U/mg) and diacetyl-acetoin (22.5 U/mg) in the oxidative and reductive reactions, respectively. Gas chromatrography analysis indicated that AdhD produced mainly (S)-2-pentanol (enantiomeric excess, 89%) when 2-pentanone was used as substrate. The physiological role of AdhD is discussed.