However, cells grown on 2-hydroxy-1-naphthoic acid failed to oxidize phenanthrene, but did oxidize salicylic acid and catechol. On the other hand, cells grown on salicylic acid failed to oxidize both phenanthrene and 2-hydroxy-1-naphthoic Selleck Navitoclax acid apart from catechol. Oxygen uptake rates were found to be in the range of 23–40 nmol of oxygen consumed per minute per milligram of protein. Moreover, the immediate oxygen-incorporating
activity of the enzymes involved in phenanthrene degradation was not observed with any of the above substrates with succinate-grown cells. It is therefore believed that the oxygen-incorporating enzymes involved in the phenanthrene degradation pathway in strain PWTJD are inducible. HPLC analysis of a resting cell incubated (48 h) phenanthrene-degraded sample showed a number of well-resolved RG-7388 cell line peaks (Fig.
2), of which, peaks I–V and VII were identified as salicylic acid, catechol, 2-hydroxy-1-naphthoic acid, salicylaldehyde, 2-naphthol and the unutilized phenanthrene, respectively, on comparing their retention times, coelution profiles and UV-visible spectra (Fig. 2, inset) obtained from diode array analysis with those of the authentic compounds analyzed under identical conditions. Identification of 2-naphthol may be due to abiotic decarboxylation of 2-hydroxy-1-naphthoic acid under the experimental conditions used. In addition, the UV-visible spectrum of peak VI eluted at 17.6 min was found to be relatively similar to that of 2-hydroxy-1-naphthoic acid (III), eluted at 5.9 min. Other peaks of Fig. 2 showed neither Chlormezanone any match with the UV-visible spectral pattern nor retention behavior of the available authentic compounds that are reported as phenanthrene pathway metabolites in the literature. Compounds corresponding to peaks I, II, IV–VI were also obtained from resting
cell incubated 2-hydroxy-1-naphthoic acid-degraded samples by the strain PWTJD grown either on phenanthrene or on 2-hydroxy-1-naphthoic acid. GC-MS analysis of biodegraded products obtained from the organic extracts (neutral as well as acidic) of the spent culture (96 h) and resting cell incubation (48 h) with phenanthrene are summarized in Table 1. GC-MS data correlate well with those obtained from HPLC analysis, although 2-hydroxy-1-naphthoic acid was not detected as such because this compound was decarboxylated under the GC-MS conditions and furnished the typical spectrum of 2-naphthol (product V, Table 1). This has been verified using authentic 2-hydroxy-1-naphthoic acid under the GC conditions used. However, a methylated derivative of an acidic extract of resting cell incubation with phenanthrene indicated the presence of 2-hydroxy-1-naphthoic acid (metabolite III).