title: Mineralization of acephate, a recalcitrant organophosphate insecticide is initiated by a pseudomonad in environmental samples.
abstract: An aerobic bacterium capable of breaking down the pesticide acephate (O,S-dimethyl acetyl phosphoramidothioic acid) was isolated from activated sludge collected from a pesticide manufacturing facility. A phylogenetic tree based on the 16 S rRNA gene sequence determined that the isolate lies within the Pseudomonads. The isolate was able to grow in the presence of acephate at concentrations up to 80 mM, with maximum growth at 40 mM. HPLC and LC-MS/MS analysis of spent medium from growth experiments and a resting cell assay detected the accumulation of methamidophos and acetate, suggesting initial hydrolysis of the amide linkage found between these two moieties. As expected, the rapid decline in acephate was coincident with the accumulation of methamidophos. Methamidophos concentrations were maintained over a period of days, without evidence of further metabolism or cell growth by the cultures. Considering this limitation, strains such as described in this work can promote the first step of acephate mineralization in soil microbial communities.
authors.affiliation: Department of Animal Sciences, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad, India.
authors.forename: Aleem Basha
authors.initials: AB
authors.lastname: Pinjari
authors.forename: Boris
authors.initials: B
authors.lastname: Novikov
authors.forename: Yohannes H
authors.initials: YH
authors.lastname: Rezenom
authors.forename: David H
authors.initials: DH
authors.lastname: Russell
authors.forename: Melinda E
authors.initials: ME
authors.lastname: Wales
authors.forename: Dayananda
authors.initials: D
authors.lastname: Siddavattam
mesh_terms: D002113:Calcification, Physiologic; D002244:Carbon / Q000378:metabolism; D004777:Environment; D006868:Hydrolysis; D007306:Insecticides / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism; D009946:Organothiophosphorus Compounds / Q000378:metabolism*; D010573:Pesticide Residues / Q000378:metabolism*; D063088:Phosphoramides; D010802:Phylogeny; D011549:Pseudomonas / Q000235:genetics / Q000254:growth & development*; D011552:Pseudomonas Infections / Q000235:genetics / Q000382:microbiology; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012988:Soil Microbiology; D013455:Sulfur / Q000378:metabolism; D053719:Tandem Mass Spectrometry
chemical_list: D007306:Insecticides; D009946:Organothiophosphorus Compounds; D010573:Pesticide Residues; D063088:Phosphoramides; D012336:RNA, Ribosomal, 16S; C001969:acephate; D013455:Sulfur; D002244:Carbon; C014655:methamidophos; D009584:Nitrogen