Long-chain alcohol production by yeasts

Fourteen yeast strains from six genera were analysed for the presence of long-chain alcohols, the highest levels being found in Candida albicans. The major alcohols synthesized were saturated, primary alcohols with C14, C16 or C18 chain length with relative proportions of C16 greater than C18 greater than C14. In C. albicans synthesis of long-chain alcohols occurred only after the end of exponential growth. Long-chain alcohol contents were lower in organisms grown aerobically as compared with anaerobically and contents of all three classes increased as the concentration of glucose was raised from 1.0 to 30.0% (w/v). In anaerobic cultures greatest alcohol contents were obtained using medium containing 10% (w/v) glucose. Substituting glucose (10%, w/v) with the same concentration of galactose in aerobic cultures greatly decreased contents of long-chain alcohols, while inclusion of 10% (w/v) glycerol virtually abolished their synthesis. Supplementing anaerobic cultures with odd-chain fatty acids induced synthesis of odd-chain alcohols, Nitrogen limitation induced long-chain alcohol synthesis in aerobically grown Candida maltosa and quantities were increased with conditions of glucose excess and nitrogen limitation.