Towards Simazine Monitoring in Agro-Zootechnical Productions: A Yeast Cell Bioprobe for Real Samples Screening

Abstract

Simazine is an herbicide that is able to contaminate surface waters, ground waters, and milk/dairy products, thus posing concerns in both environmental health and food safety. A yeast-based bioprobe was utilized to detect simazine in spiked real samples of livestock drinking water and raw cow’s milk. Yeast aerobic respiration was taken as short-term toxicological endpoint. We carried out comparative measures of yeast oxygen consumption between simazine-spiked samples and blank samples. Percentage interference (%ρ) on yeast aerobic respiration was calculated through the comparison of aerobic respiration of simazine-exposed and non-exposed yeast cells. The method was optimized for raw cow’s milk samples by using boric acid as fungistatic agent in order to avoid cellular proliferation. Overall, the results have shown that simazine can be detected up to concentrations five times below the EU legal concentration limits for drinking water (0.02 ppb) and cow’s milk (2 ppb) (%ρ values of 18.53% and 20.43% respectively; %RSD ≤ 15%). Dose-effect relationships of simazine were assessed. The findings of the bioassays match reasonably well with known mechanisms of toxicity and intracellular detoxification in yeast. A correlation between fat content in milk samples and analytical performance of the bioprobe was established. Results suggest the involvement of a matrix effect, presumably due to lipid sequestration of simazine. The yeast-based bioprobe has proved to be sensitive and suitable for the detection of simazine in real samples in concentrations of interest.

Amperometric Cytosensor for Studying Mitochondrial Interferences Induced by Plasticizers Bisphenol B and Bisphenol A

“…During the 24 h exposures, all the measurement glass vessels were covered with 55 mm diameter cellulose filter discs (Whatman ® qualitative filter paper, Grade 1; Sigma Aldrich, Milan, Italy) to limit water evaporation (<5%) while ensuring a proper O 2 exchange between air and yeast cell suspensions. The non-proliferation condition is a key aspect of the respirometric bioassay [36]. To guarantee a non-proliferation condition for the yeast S. cerevisiae, throughout the 24 h exposures, both blank yeast cell suspensions group and exposed yeast cell suspensions group underwent the same nutrient starving condition.…”

“…The cellular aerobic respiration is related to cellular O 2 consumption, and the final steps of aerobic cellular respiration occur in mitochondria. The cellular aerobic respiration has already proved to be a valuable biochemical and toxicological endpoint in our previous studies on mitochondrial effects induced by toxicants [35][36][37][38][39]. Such studies were carried out using the model yeast Saccharomyces cerevisiae as mediator in electrochemical biosensoristic devices.…”