Lactic acid bacteria - Promising technology for organophosphate degradation in food: A pilot study

Some microorganisms, such as bacteria and yeasts, show the ability to degrade chlorpyrifos, one of the most commonly used organophosphate pesticides. The aim of the present work was threefold: 1. to investigate the ability of six strains of lactic acid bacteria (LAB) to grow in the presence of chlorpyrifos; 2. to quantify the degradation of the pesticide by each strain and 3. to evaluate their secretion of alkaline phosphatases. All strains tested were able to grow in the presence of the pesticide and there was no difference between growth in contaminated samples compared to the controls. Alkaline phosphatase activity ranged from 0.0200 to 0.0226 U after 24 h of cultivation and there was no difference in the enzyme's secretion among strains. All LAB strains were able to degrade chlorpyrifos showing a minimum percentage of degradation of 80.3% after 24 h. The strain of Pediococcus sp. was able to reduce chlorpyrifos concentrations to below the detection limit, suggesting complete degradation of the pesticide. The LAB strains tested were able to tolerate and to grow in the presence of chlorpyrifos and to degrade it quickly and effectively, indicating their technical feasibility for the removal of this pesticide from a complex medium resembling food matrices.