Abstract
Two phenanthrene degrading bacteria were isolated from soil and identified as Burkholderia sp. strain PHN-5 and N372B. Strain N372B degraded phenanthrene rapidly in mineral salts medium without accumulation of 1-hydroxy-2-naphthoic acid and intermediate products. The phenanthrene degradation pathway by the strain N372B seemed to be in which phenanthrene was first converted to 1-hydroxy-2-naphthoic acid, 2-carboxybenzaldehyde and o-phthalic acid. Strain PHN-5 (did degrade phenanthrene, but with some accumulation of 1-hydroxy-2-naphthoic acid. This strain could not oxidize 1-hydroxy-2-naphthoic acid.
Both of these two Burkholderia strains also degraded a variety of polycyclic aromatic hydrocarbons. Strain PHN-5 had wider specificity than strain N372B. The enzymes which degraded 1-hydroxy-2-naphthoic acid to o-phthalic acid in strain N372B cells required NAD+ and Ferrous ion as their cofactors. On the other hand, the corresponding enzymes were not observed in strain PHN-5.
