RT Journal Article SR Electronic(1) A1 Cane, Patricia A. A1 Williams, Peter A.YR 1982 T1 The Plasmid-coded Metabolism of Naphthalene and 2-Methylnaphthalene in Pseudomonas Strains: Phenotypic Changes Correlated with Structural Modification of the Plasmid pWW60-1 JF Microbiology, VO 128 IS 10 SP 2281 OP 2290 DO https://doi.org/10.1099/00221287-128-10-2281 PB Microbiology Society, SN 1465-2080, AB Pseudomonas sp. NCIB 9816 contains two plasmids: pWW60, an IncP9 plasmid of 87 kb encoding genes for the catabolism of naphthalene, and pWW61, a cryptic plasmid of about 65 kb. The ability to degrade naphthalene was transferred at low frequency by conjugation from strain NCIB 9816 into a plasmid-free strain of Pseudomonas putida, PaW340. A transconjugant, PaW701, containing the naphthalene plasmid pWW60-1, metabolized naphthalene and salicylate via the ortho pathway. 2-Methylnaphthalene was not a growth substrate but was partly metabolized with accumulation of a brown compound in the medium (λ max = 440 nm). Spontaneous mutants of PaW701 with the ability to grow on 2-methylnaphthalene arose at a frequency of about 10−5. These fell into two groups. Group A mutants had no detectable salicylate hydroxylase activity and accumulated salicylate from naphthalene in culture supernatants: they appeared to grow on the pyruvate released from oxidation of the first ring of both substrates. Their plasmids all contained a 16·7 kb insert in different sites within a small, limited region of the plasmid. Group B mutants used a meta pathway for catabolism of naphthalene and 2-methylnaphthalene. Their plasmids had undergone a small deletion of from 1·2 to 1·6 kb in a region of the plasmid close to the sites of the insertions in the group A mutants., UL https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-128-10-2281