No attainable degradation solution of P8 was detected (e.g., biphenyl-2-carboxylic acid, dihydroxybiphenyl-2-carboxylic acid). These benefits suggest that this pathway has a minor function in phenanthrene degradation. Among the well-established initial metabolic pathways of phenanthrene diols, meta-cleavage (also named extradiol cleavage) is called the most dominant degradation pathways of 3,4- (or 1,2-) diol, which produce o-hydroxynaphthyl–oxobut-3-enoate (e.g., P6). In this experiment, higher concentrations of benzocoumarins (P4, P5) also revealed the identical ring opening (i.e., meta-cleavage). Ring opening of phenanthrene-9,10-diol, nevertheless, predominantly occurred by way of ortho-cleavage. Two metabolic pathways of 1-hydroxy-2-naphthoic acid (P12) happen to be proposed (Adachi et al. 1999; Balashova et al. 2001; Search engine marketing et al. 2009). These are (1) dioxygenation and orthocleavage to 2-carboxybenzapyruvate (P16) and (2) decarboxylation and hydroxylation by salicylate monooxygenase to naphthalene-1,2-diol (P15).Formula of 41203-22-9 Concentration profiles of P15 and P16 show that strain C6 could use each pathways within a nearly similar extent (Fig. 2D). As how phenanthrene diols degraded, naphthalene-1,2-diol (P15) may also undergo ortho(Annweiler et al. 2000; Vila et al. 2001) and meta-cleavage (Eaton and chapman 1992), from which the solutions are 2-carboxycinnamic acid (P18) and 2-hydroxybenzalyruvate. While 2-hydroxybenzapyruvate was not detected, the presence of coumarin (P17) and salicylic acid (P20) revealed that strain C6 could use meta- and ortho-cleavage to break naphthalene-1,2-diol. Based the metabolite profiles, 2-formylbenzoic acid (P19), a precursor of phthalic acid (P21), might be developed from naphthalene-1,2-diol (P15) and 2-carboxybenzalpyruvate (P16) plus the contribution of P15 and P16 are approximately equal around the production of P19. The volume of phthalic acid (P21) enhanced as much as 42 on the total identifiable metabolites by the finish of experiment (14 d), which suggests a restricted degradation. Having said that, a concomitant increase of protocatechuic acid (P22) showed that phthalic acid is definitely an intermediate of further metabolism.Price of 5-Cyclopropyl-1H-imidazole The concentration of salicylic acid (P20) also increased. No metabolites ofNIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author ManuscriptInt Biodeterior Biodegradation. Author manuscript; available in PMC 2014 April 01.Gao et al.Pagesalicylic acid (e.PMID:33638093 g., gentisic acid and catechol), on the other hand, had been detected through the complete experiment. These results suggest that salicylic acid and related metabolites usually are not major metabolites and enzymes in strain C6 might have a limited degradation possible for salicylates.NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author Manuscript5. ConclusionPhenanthrene is usually absolutely degraded by S. maltophilia strain C6 by means of 1,2-, three,4-, and 9,10-dioxygenations. 3,4-Dioxygenation and subsequent metabolisms have been most dominant. Phenanthrene diols have been transformed to o-hydroxynaphthoates or naphthalene-1,2dicarboxylic acid by way of ortho-, and meta-cleavage. Subsequent metabolism of those acids created naphthalene-1,2-diol or 2-carboxybenzalpyruvate, which is further degraded to protocatechuic acid and salicylic acid. The metabolite profiles suggest involvement of several enzymes in PAH metabolism in this strain. Complicated metabolic pathways indicate that S. maltophilia C6 has been effectively adapted to use phenanthrene as a substrate and it has application potentials for bioremediation of PAHs contamination.Ac.
