title: p-Cymene pathway in Pseudomonas putida: selective enrichment of defective mutants by using halogenated substrate analogs.
abstract: Several classes of mutants of Pseudomonas putida (JT810) defective in the utilization of p-cymene as sole carbon source have been isolated. Selective enrichment of the mutants and for strains putatively cured of a degradative plasmid was achieved by incubation of cells in minimal growth media containing p-cymene (or p-cumate) and various halogenated analogs of the growth substrates or pathway intermediates. Analogs which led to successful enrichments included: p-chlorotoluene, p-bromotoluene, alpha-chloro-p-xylene, and p-iodobenzoate. A mutant strain, PpJT811, constitutive for the p-cymene pathway gave significantly greater enrichments of defective mutants than the wild-type parent PpJT810 after incubation with the halogenated analogs. It is suggested that the defective mutants are enriched because of the genetic alterations they possess, which confer immunity to a lethal synthesis performed by transformation of the analogs in clones possessing an intact p-cymene pathway. A nomenclature for the genetic organization of p-cymene pathway is described.
mesh_terms: D001711:Biotransformation; D000081007:Cymenes; D006846:Hydrocarbons, Halogenated / Q000378:metabolism; D007463:Iodobenzoates / Q000378:metabolism; D039821:Monoterpenes; D009154:Mutation; D011549:Pseudomonas / Q000235:genetics / Q000378:metabolism*; D013329:Structure-Activity Relationship; D013729:Terpenes / Q000378:metabolism*
chemical_list: D000081007:Cymenes; D006846:Hydrocarbons, Halogenated; D007463:Iodobenzoates; D039821:Monoterpenes; D013729:Terpenes; C007210:4-cymene