Development and removal ability of non-toxigenic Aspergillus section Flavi in presence of atrazine, chlorpyrifos and endosulfan Desarrollo y capacidad de remoción de los pesticidas atrazina, clorpirifós y endosulfán por parte de cepas de Aspergillus sección Flavi no toxigénicas

BARBERIS, CARLA L.; CARRANZA, CECILIA S.; MAGNOLI, KAREN; BENITO, NICOLÁS; MAGNOLI, CARINA E.

REVISTA ARGENTINA DE MICROBIOLOGíA

ASOCIACION ARGENTINA MICROBIOLOGIA

Año: 2018

0325-7541

This study evaluated the in vitro effect of three concentrations of atrazine, chlorpyrifos and endosulfan on the growth parameters of four non-toxigenic Aspergillus section Flavi strains. The ability of the strains to remove these pesticides in a synthetic medium was also determined. Growth parameters were measured on soil extract solid medium supplied with 5, 10 and 20 mg/l of each pesticide, and conditioned to −0.70, −2.78, −7.06 and −10.0 water potential (MPa). Removal assays were performed in Czapek Doc medium (CZD) supplied with 20 mg/l of each pesticide under optimal environmental conditions (−2.78 of MPa and 25 °C). The residual levels of each pesticide were detected by the reversed-phase HPLC/fluorescence detection system. The lag phases of the strains significantly decreased in the presence of the pesticides with respect to the control media. This result indicates a fast adaptation to the conditions assayed. Similarly, the mycelial growth rates in the different treatments increased depending on pesticide concentrations. Aspergillus oryzae AM 1 and AM 2 strains showed high percentages of atrazine degradation (above 90%), followed by endosulfan (56 and 76%) and chlorpyrifos (50 and 73%) after 30 days of incubation. A significant (p < 0.001) correlation (r = 0.974) between removal percentages and growth rate was found. This study shows that non-toxigenic Aspergillus section Flavi strains from agricultural soils are able to effectively grow in the presence of high concentrations of atrazine, chlorpyrifos and endosulfan under a wide range of MPa conditions. Moreover, these strains have the ability to remove high levels of these pesticides in vitro in a short time.