Among the numerous yeasts able to produce flavor compounds, several strains of Kluyveromyces species are known for the synthesis of large amounts of aromatic compounds. In particular, the accumulation of 2-phenylethyl alcohol in liquid cultures of Kluyveromyces marxianus was observed after incubation on a semisynthetic medium at 30 degrees C, 125 rpm. Changes in the carbon sources led to a significant modification of the amount of this aromatic compound; moreover, the variations in the level of DL-phenylalanine and the exclusive use of a precursor isomer (L) also affected the synthesis of 2-phenylethyl alcohol. Finally, this study revealed the growth inhibition of K. marxianus when the concentration of 2-phenylethyl alcohol reached a critical value near 1.4 g/L; the use of an exponential model allowed the inhibition constant k(i) to be determined (k(i) = 0.35 g/L).