New and highly active microbial phosphotriesterase sources

• Published in: FEMS microbiology letters 2016-12, Vol.363 (24), p.fnw276
• Main Authors: Santillan, Julia Y., Dettorre, Lucas A., Lewkowicz, Elizabeth S., Iribarren, Adolfo M.
• Format: Article
• Language: English
• Subjects: Bacteriological Techniques - methods; Bioremediation; Caulobacteraceae - enzymology; Chemical warfare; Chemical warfare agents; Detoxification; Ecological effects; Enzyme Stability; Hydrogen-Ion Concentration; Hydrolysis; Insecticides; Mass Screening - methods; Microbiology; Microorganisms; Nocardia asteroides - enzymology; Organophosphorus compounds; Phosphoric Triester Hydrolases - analysis; Phosphoric Triester Hydrolases - chemistry; Phosphotriesterase; Soil contamination; Soil pollution; Soil temperature; Strains (organisms); Streptomyces - enzymology; Temperature
• ISSN: 1574-6968; 0378-1097; 1574-6968
• DOI: 10.1093/femsle/fnw276

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. A simple fluorimetric screening allowed the selection of six wild-type microorganisms with high phosphotriesterase activity that could be used for the decontamination of organophosphorus compounds and for biotechnological applications.