Ccr. Allen et al., METABOLISM OF NAPHTHALENE, 1-NAPHTHOL, INDENE, AND INDOLE BY RHODOCOCCUS SP STRAIN NCIMB-12038, Applied and environmental microbiology, 63(1), 1997, pp. 151-155
The regulation of naphthalene and 1-naphthol metabolism in a Rhodococc
us sp. (NCIMB 12038) has been investigated. The microorganism utilizes
separate pathways for the degradation of these compounds, and they ar
e regulated independently, Naphthalene metabolism was inducible, but n
ot by salicylate, and 1-naphthol metabolism, although constitutive, wa
s also repressed during growth on salicylate. The biochemistry of naph
thalene degradation in this strain was otherwise identical to that fou
nd in Pseudomonas putida, with salicylate as a central metabolite and
naphthalene initially being oxidized via a naphthalene dioxygenase enz
yme to cis-(1R,2S)-1,2-dihydroxy-1,2-dihydronaphtalene (naphthalene ci
s-diol). A dioxygenase enzyme was not expressed under growth condition
s which facilitate 1-naphthol degradation, However, biotransformations
with indene as a substrate suggested that a monooxygenase enzyme may
be involved in the degradation of this compound, Indole was transforme
d to indigo by both naphthalene-grown NCIMB 12038 and by cells grown i
n the absence of an inducer, Therefore, the presence of a naphthalene
dioxygenase enzyme activity was not necessary for this reaction. Thus,
the biotransformation of indole to indigo may be facilitated by anoth
er type of enzyme (possibly a monooxygenase) in this organism.