NAH PLASMID-MEDIATED CATABOLISM OF ANTHRACENE AND PHENANTHRENE TO NAPHTHOIC ACIDS

Pseudomonas fluorescens 5R contains an NAH7-like plasmid (pKA1), and P . fluorescens 5R mutant 5RL contains a bioluminescent reporter plasmid (pUTK21) which was constructed by transposon mutagenesis. Polymerase chain reaction mapping confirmed the localization of lux transposon Tn 4431 300 bp downstream from the start of the nahG gene. Two degradatio n products, 2-hydroxy-3-naphthoic acid and 1-hydroxy-2-naphthoic acid, were recovered and identified from P. fluorescens 5RL as biochemical metabolites from the biotransformation of anthracene and phenanthrene, respectively. This is the first report which provides direct biochemi cal evidence that the naphthalene plasmid degradative enzyme system is involved in the degradation of higher-molecular-weight polycyclic aro matic hydrocarbons other than naphthalene.