Fig. 4From: Protein aggregation and membrane lipid modifications under lactic acid stress in wild type and OPI1 deleted Saccharomyces cerevisiae strainsSecond derivatives of the FTIR absorption spectra of S. cerevisiae BY4741 cells, in the absence and in the presence of lactic acid: stationary phase. Cells were grown in shake flasks in minimal (YNB) medium with 2 % w/v glucose in the absence and in the presence of 46 g/L of lactic acid (LA) at pH3. FTIR analysis was performed at 40 h after the inoculation, corresponding to the stationary phase of growth. a: amide I band; b: vibrational modes mainly due to lipid CH2/CH3 and to phosphate groups, c: stretching modes from lipid hydrocarbon tails. In a and b second derivative spectra have been normalized to the tyrosine band at ~1516 cm−1, while in c spectra have been normalized at the CH3 band at ~2959 cm−1 Back to article page