The effect of the fungicide captan onSaccharomyces cerevisiaeand wine fermentation

Abstract

Abstract. Fungicides, particularly those used during grape maturation, as captan, can affect the natural yeast population of grapes, and can reach grape must affecting wine fermentation. The objective of the present work was to study the effect of captan on the viability and fermentative behavior of S. cerevisiae. S. cerevisiae (BY4741) on exponential phase was treated with captan (0 to 40 µM) for different periods, and their cell viability analyzed. Cell membrane integrity, thiols concentration, and reactive oxygen species (ROS) accumulation was determined. The fermentation experiments were conducted in synthetic must using wine yeast strain Y904. The results showed that under aerobic conditions, 20 µM of captan reduce 90% of yeast viability in 6 hours. Captan treated cells exhibited alteration of membrane integrity, reduction of thiol compounds and increase in intracellular ROS concentration, suggesting a necrotic and pro-oxidant activity of the fungicide. Fermentative experiments showed that concentrations above 2.5 µM captan completely inhibited fermentation, while a dose dependent fermentation delay associated with the reduction of yeast viability was detected in sub-inhibitory concentrations. Petit mutants increase was also observed. In conclusion, the captan induces yeast necrotic cell death on both aerobic and anaerobic conditions causing fermentation delay and/or sucking fermentations.

Bacterial and fungal components of the gut microbiome have distinct, sex-specific roles in HawaiianDrosophilareproduction

“…Bacteria were targeted using a cocktail of kanamycin, ampicillin, tetracycline, and erythromycin. Fungi were suppressed with the broad-spectrum fungicide captan, known to inhibit ascomycete fungi, epiphytic and wine yeasts including Saccharomyces cerevisiae (Magoye et al, 2020;Scariot FJ, 2016). We initially tested a second common fungicide, benomyl (1-(Butylcarbamoyl)-1H-1,3-benzimidazol-2-yl methylcarbamate) (Summerbell, 1993) but found it to be lethal for flies after 1-2 weeks of administration.…”

Yeast diversity in the vineyard: how it is defined, measured and influenced by fungicides

“…captan, captafol, folpet; FRAC M4), which interferes with cellular respiration and glycolysis. Captan is a broad‐spectrum fungicide that can affect non‐target microorganisms including wine yeast (Scariot et al 2016b).…”

“…These findings imply that the complex matrix that is unfiltered grape must offers protection to yeast, perhaps by absorption of fungicide residues onto particles in the must. Other factors such as a difference in pH can also impact fungicide inhibition, with low pH values enhancing fungicide disassociation and thereby producing different MIC values compared to tests at a neutral pH (Scariot et al 2016a,b).…”

“…Yeast cells treated with captan exhibited altered membrane integrity, reduction of thiol compounds and an increase in intracellular reactive oxygen species. A concentration of 2.5 μmol/L of captan completely inhibits fermentation with a dose‐dependent delay when a lower concentration was tested (Scariot et al 2016b, 2017).…”

Tagatose Suppresses Grapevine Powdery Mildew and Downy Mildew under Field Conditions with No Severe Impacts on Grape Must Fermentation

“…Likewise, treatments with sulfur against powdery mildew can leave residues and negatively afect yeast biodiversity in spontaneous must fermentation [24] because of the selective efects of sulfur on diferent yeast taxa [25]. In conventional agriculture, several synthetic chemical fungicides are applied for downy mildew and powdery mildew control (e.g., ametoctradin, captan, dimethomorph, fenarimol, folpet, kresoxim-methyl, quinoxyfen, and penconazole), and they may have a negative impact on S. cerevisiae fermentation [24,[26][27][28] and on sensory wine characteristics [29,30], indicating that their use should be concluded sufciently in advance before harvest. Although several potential alternatives to sulfur, copper, and synthetic chemical fungicide have been studied [7,15,31,32], their potential side efects on must fermentations have seldom been investigated.…”