RESUMEN
The ability of Pseudomonas fluorescens 26K strain to utilize naphthalene at concentrations up to 600 mg/liter as the sole source of carbon and energy in mineral liquid media was shown. Using HPLC, TLC, and mass-spectrometry, the intermediates of naphthalene transformation by this strain were identified as naphthalene cis-1,2-dihydrodiol, salicylaldehyde, salicylate, catechol, 2-hydroxymuconic semialdehyde, and 1-naphthol. Catechol 2,3-dioxygenase (a homotetramer with native molecular mass 125 kDa) and NAD+-dependent homohexameric naphthalene cis-1,2-dihydrodiol dehydrogenase with native molecular mass 160 kDa were purified from crude extract of the strain and characterized. NAD+-dependent homodimeric salicylaldehyde dehydrogenase with molecular mass 110 kDa was purified and characterized for the first time. Based on the data, a pathway of naphthalene degradation by P. fluorescens 26K is suggested.
Asunto(s)
Aldehído Oxidorreductasas/química , Catecol 2,3-Dioxigenasa/química , Naftalenos/metabolismo , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH/química , Pseudomonas fluorescens/enzimología , Aldehído Oxidorreductasas/aislamiento & purificación , Aldehídos/análisis , Catecol 2,3-Dioxigenasa/aislamiento & purificación , Catecoles/análisis , Cromatografía Líquida de Alta Presión , Electroforesis en Gel de Poliacrilamida , Ácidos Grasos Insaturados/análisis , Espectrometría de Masas , Naftoles/análisis , Oxidorreductasas actuantes sobre Donantes de Grupo CH-CH/aislamiento & purificación , Salicilatos/análisisRESUMEN
The cells of Rhodococcus opacus 412 and R. rhodnii 135 were adapted to phenanthrene and anthracene on a solid mineral medium. Preliminary adaptation of the strains accelerated the metabolism of polyaromatic hydrocarbons and provided for the ability of microorganisms to grow on pheanthrene as a sole carbon and energy source in a liquid mineral medium. It was shown that phenanthrene was mineralized by the strains through 7,8-benzocoumarin, 1-hydroxy-2-naphthoaldehyde, 1-hydroxy-2-naphthoic acid, salicylaldehyde, salicylate and catechol to the intermediates of tricarbonic acid cycle and partially transformed with the accumulation of the products of subsequent monooxygenation (3-hydroxyphenanthrene and phenanthrene dihydroxylated not in ortho-position). As a result of the adaptation of the strains to anthracene on a solid mineral medium, the obtained variant of strain R. opacus 412 was able to transform anthracene in a liquid mineral medium to anthraquinone and 6,7-benzocoumarin.