Effect of Citrus essential oil addition upon growth and cellular lipids of Yarrowia lipolytica yeast

The chemical composition of the essential oil from fruits of the Greek citrus hybrid Citrus sinensis cv New Hall - Citrus aurantium was investigated by GC and GC-MS. Forty-four compounds were identified, representing 92.83% of the total oil. Limonene, myrcene, β-pinene, α-pinene and α-terpineol constituted the major components of the oil. The effect of the addition of this oil upon the behavior of Yarrowia lipolytica yeast was also investigated. The microorganism was aerobically grown on glucose and oil was added to the culture medium in various initial quantities (from 0.0 to 1.5 mL/L). The strain underwent significant inhibition exerted by the added essential oil; a decrease of the highest achieved biomass concentration, even if the oil was added to the culture medium at small concentrations (e.g. 0.3 mL/L), was observed. The more oil was added, the more the lag phase of the growth increased, while the biomass yield on glucose consumed decreased with the addition of the oil. When the essential oil was added to the medium, even at small concentrations, a significant increase of cellular medium-chain saturated fatty acids (12:0 and 14:0) resulting in an increase of saturated fatty acid content in the cellular lipids, was observed. © 2008 Wiley-VCH Verlag GmbH & Co. KGaA