Organophosphate compounds are widely used in agricultural activities to optimize food production. Contaminationof field soil by these compounds may result in detrimental effects on soil biota. The aim of the present s...Organophosphate compounds are widely used in agricultural activities to optimize food production. Contaminationof field soil by these compounds may result in detrimental effects on soil biota. The aim of the present studywas to isolate microorganisms from field soils and evaluate the strains on ability to degrade organophosphates as singleisolate and as a consortium. Isolated strains were identified using both biochemical and molecular techniques.Results revealed that, out of the 46 isolated strains, three isolates herein referred to as S6, S36 and S37 showed an averagediazinon degradation rate of 76.4%, 76.7% and 76.8% respectively, of the initial dose (50 ppm) within 11 daysof incubation in mineral medium. Notably, isolates S36 and S37 were more effective than S6 in degrading diazinonby 40% in soil aliquot after 11 days and therefore were evaluated on biochemical reactions and molecular identification.The isolates showed variable biochemical characteristics. However, both isolates possessed catalase enzyme,but lacked oxidase enzyme. Molecular characterization showed that, the closest species for S36 and S37 were Priestiamegaterium and P. arybattia, respectively, based on 16S rRNA gene similarity (> 99%). Combination of the strainsincreased diazinon degradation ability by 45% compared to single strain treatment. Chlorpyrifos was the most highlydegraded organophosphate, compared to phorate and cadusafos. Therefore it is expected that the pesticide-degradingbacteria could be a solution to soil health improvement and contribution to the production of safe agriculturalproducts.展开更多
文摘Organophosphate compounds are widely used in agricultural activities to optimize food production. Contaminationof field soil by these compounds may result in detrimental effects on soil biota. The aim of the present studywas to isolate microorganisms from field soils and evaluate the strains on ability to degrade organophosphates as singleisolate and as a consortium. Isolated strains were identified using both biochemical and molecular techniques.Results revealed that, out of the 46 isolated strains, three isolates herein referred to as S6, S36 and S37 showed an averagediazinon degradation rate of 76.4%, 76.7% and 76.8% respectively, of the initial dose (50 ppm) within 11 daysof incubation in mineral medium. Notably, isolates S36 and S37 were more effective than S6 in degrading diazinonby 40% in soil aliquot after 11 days and therefore were evaluated on biochemical reactions and molecular identification.The isolates showed variable biochemical characteristics. However, both isolates possessed catalase enzyme,but lacked oxidase enzyme. Molecular characterization showed that, the closest species for S36 and S37 were Priestiamegaterium and P. arybattia, respectively, based on 16S rRNA gene similarity (> 99%). Combination of the strainsincreased diazinon degradation ability by 45% compared to single strain treatment. Chlorpyrifos was the most highlydegraded organophosphate, compared to phorate and cadusafos. Therefore it is expected that the pesticide-degradingbacteria could be a solution to soil health improvement and contribution to the production of safe agriculturalproducts.
