Phenanthrene metabolism by Pseudomonas and Burkholderia strains

Five pseudomonads and two Burkholderia spp. capable of utilizing naphthalen e or phenanthrene as a sole source of carbon and energy were isolated from oil-contaminated soils through enrichment cultures. All the strains studied contained large plasmids. In six strains, they were involved in biodegrada tion of specific substrates. The major intermediates of phenanthrene metabo lism accumulated in the culture liquids were 1-hydroxy-2-naphthoate and 2-h ydroxy-1-naphthoate. The strains studied differed in the accumulation patte rn of these intermediates. 2-Naphthol, an oxidation product of 2-hydroxy-1- naphthoate, exerted a toxic effect on microorganisms. The phenanthrene-degr ading activity of Pseudomonas strains depended on their ability to utilize 1-hydroxy-2 naphthoate. In the Pseudomonas strains under study, phenanthren e metabolism involved the enzymes of naphthalene degradation. (C) 1999 Else vier Science Ltd. All rights reserved.