Production of ethyl alcohol by Saccharomyces cerevisiae, including utilization of onion juice

The production of ethyl alcohol by Saccharomyces cerevisiae in nine synthetic culture media was influenced by their composition. Generally, no correlation seemed to exist between mycelial growth and ethyl alcohol production. Different cultural conditions were investigated using one basal synthetic medium. Sodium or potassium nitrate had an adverse effect while ammonium dihydrogen phosphate, yeast extract, casein, soybean meal, peptone and meat extract had stimulating effects on the production of alcohol. The effect of the addition of other substances, including onion juice, to the synthetic culture medium was also investigated. In higher concentration, onion juice alone fulfilled all the requirements for the production of a good yield of ethyl alcohol by Saccharomyces cerevisiae. This was also associated with a good yield of yeast cells.