Fig. 7From: Assessing an effective feeding strategy to optimize crude glycerol utilization as sustainable carbon source for lipid accumulation in oleaginous yeastsFTIR analysis of yeast cell wall modifications during lipid accumulation. The second derivatives of the FTIR spectra of yeast cells are reported in the spectral range comprised between 1200–950 cm−1, mainly ascribable to the absorption of cell wall carbohydrates. Spectra of control (a) and oleaginous yeasts C. curvatus (b) R. toruloides (c), and L. starkeyi (d) are displayed at time 0 and at 144 h of growth in crude and pure glycerol. For comparison, the second derivative spectra have been normalized at the tyrosine band at ~1516 cm−1 Back to article page