Fig. 1

Lucifer yellow uptake in yeast cells exposed to propionic acid. Yeast cells were treated with propionic acid, nonanal, or a carrier control in the presence of lucifer yellow. A shows the mean fluorescence of yeast cells with standard error bars (n = 3). Different letters indicate significant differences (p < 0.001). B shows micrographs in brightfield (top) and fluorescence (bottom) channels that contrast lucifer yellow uptake in yeast cells in a no-treatment negative control (left) compared to treatment with propionic acid (right). The white scale bar represents 25 µm