Metabolism of carbaryl via 1,2-dihydroxynaphthalene by soil isolates Pseudomonas sp. strains C4, C5, and C6.
Pseudomonas sp. strains C4, C5, and C6 utilize carbaryl as the sole source of carbon and energy. Identification of 1-naphthol, salicylate, and gentisate in the spent media; whole-cell O2 uptake on 1-naphthol, 1,2-dihydroxynaphthalene, salicylaldehyde, salicylate, and gentisate; and detection of key enzymes, viz, carbaryl hydrolase, 1-naphthol hydroxylase, 1,2-dihydroxynaphthalene dioxygenase, and gentisate dioxygenase, in the cell extract suggest that carbaryl is metabolized via 1-naphthol, 1,2-dihydroxynaphthalene, and gentisate. Here, we demonstrate 1-naphthol hydroxylase and 1,2-dihydroxynaphthalene dioxygenase activities in the cell extracts of carbaryl-grown cells. 1-Naphthol hydroxylase is present in the membrane-free cytosolic fraction, requires NAD(P)H and flavin adenine dinucleotide, and has optimum activity in the pH range 7.5 to 8.0. Carbaryl-degrading enzymes are inducible, and maximum induction was observed with carbaryl. Based on these results, the proposed metabolic pathway is carbaryl --> 1-naphthol --> 1,2-dihydroxynaphthalene --> salicylaldehyde --> salicylate --> gentisate --> maleylpyruvate.
Swetha
Vandana P
VP
Biotechnology Group, School of Biosciences and Bioengineering, Indian Institute of Technology, Bombay, Powai, Mumbai 400 076, India.
Phale
Prashant S
PS
D012721:Carbaryl / Q000378:metabolism*; D003470:Culture Media; D049308:Dioxygenases / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D009284:Naphthols / Q000378:metabolism*; D010105:Oxygenases / Q000378:metabolism; D011549:Pseudomonas / Q000145:classification / Q000201:enzymology* / Q000302:isolation & purification; D012988:Soil Microbiology
D003470:Culture Media; D009284:Naphthols; C050642:1,2-dihydroxynaphthalene; D010105:Oxygenases; D049308:Dioxygenases; D012721:Carbaryl