초록
<P>Isoamyl acetate is a natural flavour ester, widely used as a source of banana flavour by the food industry. <I>Williopsis saturnus</I> var. <I>saturnus</I> is a yeast which can produce isoamyl acetate by esterification of amyl alcohols with acetyl coenzyme A via fermentation. The evaluation of this kind of production as an alternative way to obtain natural banana flavour could be possible, if the levels produced were high enough to make a commercial product. In this study, the effects of temperature (15°C and 25°C) and aeration (aerobic, semiaerobic, and anaerobic) on the production of isoamyl acetate by <I>Williopsis saturnus</I> var. <I>saturnus</I> from sugar beet molasses were examined. According to the results obtained, isoamyl acetate production rate and specific productivity were higher at 25°C than at 15°C and at semiaerobic condition than aerobic and anaerobic conditions. <I>Williopsis saturnus</I> var. <I>saturnus</I> showed a production rate of 0.703 mg L<SUP>−1</SUP> h<SUP>−1</SUP> and a specific productivity of 0.0297 mg L<SUP>−1</SUP> cell<SUP>−1</SUP> h<SUP>−1</SUP> isoamyl acetate with semiaerobic condition at 25°C. The maximum amount of isoamyl acetate reached with these conditions was 118 mg/L.</P>