An efficient enzymatic baeyr-villiger oxidation by engineered escherichia coli cells under non-growing conditions

摘要

Econcomical methods of supplying NADPH must be developed before biotransformations involving this cofactor can be considered for large-scale applications.We have studied the enzymatic Baeyer-Villiger oxidation of cyclohezanone as a model for this class of reactions and developed a simple approach that uses whole,non-growing Escherichia coli cells to provide high productivity(0.79 g #epsilon#-caprolactone/L/h ident to 18#mu#mol #epsilon#-caprolactone/min/g dcw)and an 88% yield.Glucose supplied the reducing equivalents for non-growing cells was an order of magnitude greater than that achieved with growing cells of the same strain.Cells of an engineered E.coli strain that overexpresses Acinetobacter sp.cyclohexanone monooxygenase were grown under inducing conditions in rich medium until the entry to stationary phase;the subsequent cyclohexanone oxidation was carried out in minimal salte medium lacking a nitrogen source.After the biotransformation was complete,the lactone product was adsorbed to a solid support and recovered by washing with an organic solvent.