Production of esters by Staphylococci.

The ability of resting cells and extracellular concentrates of Staphylococci to synthesize ethyl esters was studied in the presence of ethanol and short chain acids considered individually. All the strains synthesized ethyl esters, S. warneri was the highest producer and S. carnosus the lowest. Resting cells esterified preferentially butanoic acid, extracellular concentrates esterified butanoic, valeric and hexanoic acids. Acetic, decanoic and branched acids were poorly esterified. The activity of the extracellular concentrates with ethanol and butanoic acid was not modified by the pH (pH 5.5 or 7.0); but it was decreased at a temperature of 14 degrees C compared to 24 degrees C. For the resting cells it was the opposite, the activity was inhibited by acid pH and was not influenced by the temperatures. So the Staphylococci could produce esters during sausage manufacture.