title: New and highly active microbial phosphotriesterase sources.
abstract: Many toxic insecticides used worldwide as well as some chemical warfare agents are phosphotriester derivatives. Therefore, detoxification of organophosphorus compounds has become the subject of many studies and in particular bioremediation, based on the phosphotriesterase catalysed hydrolysis of these compounds, has shown to be an effective and ecological methodology. In order to identify new bacterial phosphotriesterases, a simple and sensitive fluorimetric screening method on solid media was employed that allowed the selection of six strains with phosphotriesterase activity. Since pH and temperature are important parameters for bioremediation of contaminated soils and waters, the influence of these variables on the rate of the enzymatic hydrolysis was assessed. This study afforded notable results, being the most remarkable one the increased activity exhibited by Nocardia asteroides and Streptomyces setonii strains at 50°C, 7 and 30 times higher than at 30°C, respectively. Compared with the results obtained with Brevundimonas diminuta, whose activity is usually considered as reference, an increase of 26 and 75 times is observed, respectively.
authors.affiliation: Laboratorio de Biocatálisis y Biotransformaciones, Universidad Nacional de Quilmes, 1876 Bernal, Buenos Aires, Argentina.
authors.forename: Julia Y
authors.initials: JY
authors.lastname: Santillan
authors.affiliation: Laboratorio de Biocatálisis y Biotransformaciones, Universidad Nacional de Quilmes, 1876 Bernal, Buenos Aires, Argentina.
authors.forename: Lucas A
authors.initials: LA
authors.lastname: Dettorre
authors.affiliation: Laboratorio de Biocatálisis y Biotransformaciones, Universidad Nacional de Quilmes, 1876 Bernal, Buenos Aires, Argentina.
authors.forename: Elizabeth S
authors.initials: ES
authors.lastname: Lewkowicz
authors.affiliation: Laboratorio de Biocatálisis y Biotransformaciones, Universidad Nacional de Quilmes, 1876 Bernal, Buenos Aires, Argentina airibarren@unq.edu.ar.
authors.forename: Adolfo M
authors.initials: AM
authors.lastname: Iribarren
mesh_terms: D001431:Bacteriological Techniques / Q000379:methods; D042063:Caulobacteraceae / Q000201:enzymology*; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D008403:Mass Screening / Q000379:methods; D009616:Nocardia asteroides / Q000201:enzymology; D044345:Phosphoric Triester Hydrolases / Q000032:analysis* / Q000737:chemistry; D013302:Streptomyces / Q000201:enzymology*; D013696:Temperature
chemical_list: D044345:Phosphoric Triester Hydrolases
keywords: Brevundimonas diminuta; Streptomyces setonii; bioremediation Nocardia asteroides; organophosphorus compounds; phosphotriesterase