Development and removal ability of non-toxigenic Aspergillus section Flavi in presence of atrazine, chlorpyrifos and endosulfan

Rev Argent Microbiol. Jan-Mar 2019;51(1):3-11. doi: 10.1016/j.ram.2018.03.002. Epub 2018 Jun 7.

Abstract

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 20mg/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 20mg/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.

Keywords: Aspergillus flavus; Aspergillus oryzae; Atrazina; Atrazine; Chlorpyrifos; Clorpirifós; Endosulfan; Endosulfán; Growth parameters; Parámetros de crecimiento; Remoción; Removal.

MeSH terms

  • Aspergillus flavus / drug effects
  • Aspergillus flavus / growth & development*
  • Aspergillus flavus / metabolism*
  • Atrazine / administration & dosage*
  • Atrazine / metabolism*
  • Atrazine / pharmacology
  • Chlorpyrifos / administration & dosage*
  • Chlorpyrifos / metabolism*
  • Chlorpyrifos / pharmacology
  • Dose-Response Relationship, Drug
  • Endosulfan / administration & dosage*
  • Endosulfan / metabolism*
  • Endosulfan / pharmacology
  • Herbicides / administration & dosage*
  • Herbicides / pharmacology
  • Insecticides / administration & dosage*
  • Insecticides / pharmacology

Substances

  • Herbicides
  • Insecticides
  • Chlorpyrifos
  • Endosulfan
  • Atrazine