Abstract | We have now determined the complete gene sequence of the cyclohexanol (chn) degradation pathway in Acinetobacter sp. NCIMB 9871 as well as the putative genes for the β-oxidation of adipic acid to acetyl-CoA and succinyl-CoA. In addition, a new insertion sequence, potentially useful in strain characterization, was identified. Knowledge of the nucleotide sequence of the chn genes was used to construct clones of Escherichia coli that would overproduce the requisite biocatalysts: a flavin monooxygenase (ChnB; cyclohexanone 1,2-monooxygenase [CHMO]), a ring-opening hydrolase (ChnC; ε-caprolactone hydrolase) and three oxido-reductases (ChnA, cyclohexanol dehydrogenase; ChnD, 6-hydroxyhexanoate dehydrogenase; and ChnE, 6-oxohexanoate dehydrogenase). Besides the well known application of CHMO as a Baeyer-Villiger biocatalyst that carries out stereoselective oxidations of a wide variety of ketones to the corresponding lactones, potential applications of the Chn biocatalysts in the development of "green" bioprocesses such as an "envirocompatible" synthesis of adipic acid are discussed. |
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