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Evaluation of Alcaligenes eutrophus cells as an NADH regenerating catalyst in organic‐aqueous two‐phase system
Author(s) -
Andersson Mats,
Holmberg Hans,
Adlercreutz Patrick
Publication year - 1998
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/(sici)1097-0290(19980105)57:1<79::aid-bit10>3.0.co;2-3
Subject(s) - chemistry , catalysis , cyclohexanol , cyclohexanone , alcohol dehydrogenase , hydrogenase , organic chemistry , aqueous solution , aqueous two phase system , alcohol
A soluble NAD‐dependent hydrogenase contained in Alcaligenes eutrophus was evaluated as a coenzyme regenerating catalyst in an organic‐aqueous two‐phase (predominantly organic) system. The horse‐liver alcohol‐dehydrogenase (HLADH) catalyzed reduction of cyclohexanone to cyclohexanol was used as a model reaction. The impact of different solvents (selected to span a large variety of principal properties) on the stability and activity of the HLADH, using substrate‐driven regeneration, was studied. Solvents suitable for the HLADH were then selected for an evaluation of the hydrogenase‐driven coenzyme regeneration. Hydrophobic solvents such as heptane, toluene, and 1,1,1‐trichloroethane were found to be suitable for the coupled reactions catalyzed by HLADH and hydrogenase. Nonimmobilized cells, permeabilized with cetyl‐trimethyl‐ammonium bromide, were the most efficient preparation for the regeneration of NADH. The use of this preparation in heptane (10% water) was optimized with respect to the yield obtained in the HLADH‐catalyzed reduction of cyclohexanone. Using the optimized conditions, yields of 99% cyclohexanol were obtained. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 57: 79–86, 1988.