Study of the mechanism of synthesis of Ethyl Acetate by Hansenula Anomala

The single addition of acetaldehyde to a rapidly multiplying culture of H. anomala 7 resulted in a significant increase in the synthesis of ethyl acetate. After addition of ethyl alcohol or acetate, a drop in the concentration of ester was noted. A reduction in the concentration of ethyl acetate in a rapidly growing culture of this yeast was found when sodium bisulfite, 0.001 M, was added to a medium containing acetaldehyde or ethyl alcohol. The isolation of esters from cultures of H. anomala 7 to which propionaldehyde and isopropyl, n-propyl, isobutyl, n-butyl and t-butyl alcohols were added was uniformly negative. The yeast was able to utilize the alcohols for growth. The propionaldehyde appreaed to be toxic at the concentration added. While addition if 0.008 M acetate did not increase the oxygen uptake by resting cells when in the presence of 0.2 M ethyl alcohol, its presence brought about and increase the oxygen uptake by resting cells when in the presence of 0.2 M ethyl alcohol, its presence brought about increase synthesis of ethyl acetate by resting cells of this yeast. Neither 2,4-dinitrophenol nor sodium bisulfite appeared to influence the oxygen uptake by resting cells of H. anomala 7. The data obtained using radioactive sodium acetate suggested that the majority of added acetate was rapidly oxidized to carbon dioxide and water. No measurable increase over the background count in counts per minute was observed in the ethyl acetate produced by H. anomala 7 when in the presence of labeled acetate. Isolation of cell free preparation obtained from cells of H. anomala 7 was noted. These preparations were low in enzyme activity and an increased activity could not be attained by the addition of 0.3 uM of adenosine Triphosphate or 3.0 uM of diphosphopyridine nucleotide. Acetate concentration at 0.02 M did not effect and increase in ethyl acetate synthesis with the cell free enzyme preparation.