title: Enzyme recruitment allows the biodegradation of recalcitrant branched hydrocarbons by Pseudomonas citronellolis.
abstract: Experiments were carried out to construct pseudomonad strains capable of the biodegradation of certain recalcitrant branched hydrocarbons via a combination of alkane and citronellol degradative pathways. To promote the metabolism of the recalcitrant hydrocarbon 2,6-dimethyl-2-octene we transferred the OCT plasmid to Pseudomonas citronellolis, a pseudomonad containing the citronellol pathway. This extended the n-alkane substrate range of the organism, but did not permit utilization of the branched hydrocarbon even in the presence of a gratuitous inducer of the OCT plasmid. In a separate approach n-decane-utilizing (Dec+) mutants of P. citronellolis were selected and found to be constitutive for the expression of medium- to long-chain alkane oxidation. The Dec+ mutants were capable of degradation of 2,6-dimethyl-2-octene via the citronellol pathway as shown by (i) conversion of the hydrocarbon to citronellol, determined by gas-liquid chromatography-mass spectrometry, (ii) induction of geranyl-coenzyme A carboxylase, a key enzyme of the citronellol pathway, and (iii) demonstration of beta-decarboxymethylation of the hydrocarbon by whole cells. The Dec+ mutants had also acquired the capacity to metabolize other recalcitrant branched hydrocarbons such as 3,6-dimethyloctane and 2,6-dimethyldecane. These studies demonstrate how enzyme recruitment can provide a pathway for the biodegradation of otherwise recalcitrant branched hydrocarbons.
mesh_terms: D000080462:Acyclic Monoterpenes; D000473:Alkanes / Q000378:metabolism*; D000475:Alkenes / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019735:Carbon-Carbon Ligases; D003227:Conjugation, Genetic; D004790:Enzyme Induction; D008025:Ligases / Q000096:biosynthesis* / Q000378:metabolism*; D039821:Monoterpenes; D009154:Mutation; D009795:Octanes / Q000378:metabolism; D010957:Plasmids; D011549:Pseudomonas / Q000235:genetics / Q000378:metabolism*; D013045:Species Specificity; D013729:Terpenes / Q000096:biosynthesis
chemical_list: D000080462:Acyclic Monoterpenes; D000473:Alkanes; D000475:Alkenes; D039821:Monoterpenes; D009795:Octanes; D013729:Terpenes; D008025:Ligases; D019735:Carbon-Carbon Ligases; C020566:geranoyl-CoA carboxylase; C007078:citronellol