The lethal effects of some onolophosphate insecticides on yeast Saccharomyces cerevisiae

Area of Science:

• Biochemistry
• Toxicology
• Microbiology

Background:

• Enolophosphate insecticides are widely used pesticides.
• Understanding their biological effects on non-target organisms like yeast is crucial for environmental and health risk assessment.
• Baker's yeast (Saccharomyces cerevisiae) serves as a model organism for studying cellular processes.

Purpose of the Study:

• To evaluate the biological activity of three enolophosphate insecticides: chlorphenvinphos, bromphenvinphos, and mebromvinphos.
• To investigate the impact of these insecticides on key yeast cellular functions.
• To determine the primary mechanism of cell death induced by these compounds.

Main Methods:

• Exposure of baker's yeast to varying concentrations of chlorphenvinphos, bromphenvinphos, and mebromvinphos.
• Assays to measure amino acid transport, respiration, and fermentation rates.
• Microscopic observation of yeast cells and protoplasts.
• Assessment of cell membrane integrity and sugar transport activity.
• Evaluation of genotoxicity.

Main Results:

• The insecticides caused immediate inhibition of amino acid transport, respiration, and fermentation in yeast.
• Significant disruption of cell growth and rapid cell death were observed.
• Direct damaging effects on yeast protoplasts were noted.
• The primary cause of cell death was the development of membrane leakiness.
• Loss of sugar transport activity correlated directly with loss of cell viability.
• No significant genotoxic activity was detected for any of the tested insecticides.

Conclusions:

• Enolophosphate insecticides exhibit potent toxicity towards baker's yeast, affecting fundamental cellular processes.
• Membrane leakiness is the principal mechanism leading to insecticide-induced yeast cell death.
• These findings highlight the potential for broad biological impact of these pesticides beyond their intended targets.