A non-conventional dissimilation pathway for long chain n-alkanes in Acinetobacter sp. M-1 that starts with a dioxygenase reaction

• Published in: Journal of fermentation and bioengineering Vol. 81; no. 4; pp. 286 - 291
• Main Authors: Sakai, Yasuyoshi, Maeng, Jun Ho, Kubota, Seigo, Tani, Akio, Tani, Yoshiki, Kato, Nobuo
• Format: Journal Article
• Language: English
• Published: Osaka Elsevier B.V 01.01.1996; Society for Fermentation and Bioengineering
• Subjects: ACINETOBACTER; aldehyde dehydrogenase; Biological and medical sciences; Biology of microorganisms of confirmed or potential industrial interest; Biotechnology; dioxygenase; Fundamental and applied biological sciences. Psychology; HIDROCARBUROS; HYDROCARBURE; long-chain alkane; Mission oriented research; OXIDORREDUCTASAS; OXYDOREDUCTASE; pathway; Physiology and metabolism; VIA BIOQUIMICA DEL METABOLISMO; VOIE BIOCHIMIQUE DU METABOLISME; long-chain alkane; dioxygenase; Acinetobacter; pathway; aldehyde dehydrogenase; Purification; Enzyme; Long chain; Neisseriaceae; ); Metabolic pathway; Alcohol dehydrogenase; Metabolism; Enzymatic activity; Aldehyde dehydrogenase (NAD; Alkane; Bacteria; Micrococcales; Oxidation; Oxidoreductases
• ISSN: 0922-338X
• DOI: 10.1016/0922-338X(96)80578-2

n-Alkane oxidation in a long chain n-alkane utilizer, Acinetobacter sp. M-1, was investigated. In Acinetobacter, n-alkanes have been postulated to be converted to the acid via a non-conventional oxidation pathway: n-alkane→ n-alkyl hydroperoxide→aldehyde→acid (Finnerty, W.R.: Lipids of Acinetobacter. In Proceedings of the World Conference on Biotechnology for the Fats and Oils Industry, 184–188, 1988). However, there is little biochemical information on the enzymes involved in the postulated pathway, particularly the enzyme catalyzing the first step. In this study, we purified and n-alkane-oxidizing enzyme to apparent homogeneity by SDS-PAGE. The enzyme was a flavoprotein, and required molecular oxygen and Cu 2+ for its activity, but did not require a reduced coenzyme such as NAD(P)H. A hydroperoxide was detected as a product of the enzyme reaction. We assume that the n-alkane-oxidizing enzyme is a dioxygenase. In addition, as a fatty alcohol does not appear to be an intermediate, fatty alcohol dehydrogenase is assumed not to participate in the n-alkane oxidation. The validity of the postulated pathway is supported by the following observations: (i) n-alkane monooxygenase activity was not detected, (ii) fatty alcohol dehydrogenase activities were low, and (iii) NAD(P)H-dependent long chain fatty aldehyde dehydrogenase activities were strongly induced in n-alkane-grown cells. NAD(P)H-dependent fatty aldehyde reductase activity was also found in n-alkane-grown cells, which may contribute to the formation of waxes that are cell reserve substances in n-alkane-utilizing Acinetobacter.