title: Metabolic regulation and chromosomal localization of carbaryl degradation pathway in Pseudomonas sp. strains C4, C5 and C6.
abstract: Pseudomonas sp. strains C4, C5 and C6 degrade carbaryl (1-naphthyl N-methylcarbamate) via 1-naphthol, 1,2-dihydroxynaphthalene, salicylate and gentisate. Carbon source-dependent metabolic studies suggest that enzymes responsible for carbaryl degradation are probably organized into 'upper' (carbaryl to salicylate), 'middle' (salicylate to gentisate) and 'lower' (gentisate to TCA cycle) pathway. Carbaryl and 1-naphthol were found to induce all carbaryl pathway enzymes, while salicylate and gentisate induce middle and lower pathway enzymes. The strains were found to harbor plasmid(s), and carbaryl degradation property was found to be stable. Genes encoding enzymes of the degradative pathway such as 1-naphthol 2-hydroxylase, salicylaldehyde dehydrogenase, salicylate 5-hydroxylase and gentisate 1,2-dioxygenase were amplified from chromosomal DNA of these strains. The gene-specific PCR products were sequenced from strain C6, and phylogenetic tree was constructed. Southern hybridization and PCR analysis using gel eluted DNA as template supported the presence of pathway genes onto the chromosome and not on the plasmid(s).
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology-Bombay, Powai, 400 076 Mumbai, India.
authors.forename: Randhir
authors.initials: R
authors.lastname: Singh
authors.forename: Vikas D
authors.initials: VD
authors.lastname: Trivedi
authors.forename: Prashant S
authors.initials: PS
authors.lastname: Phale
mesh_terms: D000445:Aldehyde Oxidoreductases / Q000235:genetics / Q000378:metabolism; D012721:Carbaryl / Q000378:metabolism*; D002874:Chromosome Mapping; D002876:Chromosomes, Bacterial; D049308:Dioxygenases / Q000378:metabolism; D005798:Genes, Bacterial; D005841:Gentisates / Q000378:metabolism; D053858:Metabolic Networks and Pathways; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism; D009284:Naphthols / Q000378:metabolism; D010101:Oxygen Consumption; D010802:Phylogeny; D010957:Plasmids; D011549:Pseudomonas / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D012459:Salicylates / Q000378:metabolism
chemical_list: D005841:Gentisates; D009284:Naphthols; D012459:Salicylates; C050642:1,2-dihydroxynaphthalene; D006899:Mixed Function Oxygenases; D049308:Dioxygenases; C026247:gentisate 1,2-dioxygenase; C099614:salicylic acid 5-hydroxylase; D000445:Aldehyde Oxidoreductases; C024246:salicylaldehyde dehydrogenase; D012721:Carbaryl