title: Degradation of alicyclic molecules by Rhodococcus ruber CD4.
abstract: The present work describes investigations on the bacterial degradation of the alicyclic molecule cyclododecane. It represents a structure where the initial degradative steps have to be similar to a "subterminal" attack as there is no "terminal" part of the molecule. We were able to show that the gram-positive bacterium Rhodococcus ruber CD4 DSM 44394 oxidizes cyclododecane to the corresponding alcohol and ketone, the latter being subject to ring fission by a Baeyer-Villiger oxygenase. This key enzyme is an NADPH- and O2-dependent flavoprotein with a substrate specificity for bigger rings. The further metabolism of the resulting lactone gives rise to an omega-hydroxyalkanoic acid that is susceptible to common beta-oxidation. Due to its alicyclic character and its ring size, cyclododecane is comparable to aliphatic bridge components that are an important element in the coal texture. They contribute to the three-dimensional coal structure and thus could serve as a valuable target for the oxidative abilities of R. ruber CD4 to reduce the molecular mass of coal.
authors.affiliation: Institut für Mikrobiologie und Biotechnologie, Universität Bonn, Germany.
authors.forename: J D
authors.initials: JD
authors.lastname: Schumacher
authors.forename: R M
authors.initials: RM
authors.lastname: Fakoussa
mesh_terms: D001673:Biodegradation, Environmental; D006840:Hydrocarbons, Alicyclic / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction; D010105:Oxygenases / Q000378:metabolism; D012240:Rhodococcus / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*
chemical_list: D006840:Hydrocarbons, Alicyclic; D010105:Oxygenases