[Selection of mutants of microorganisms utilizing ethanol]

Mutants of the bacteria Acinetobacter calcoaceticus 34 and Acinetobacter sp. 172 as well as of the yeast Candida requinyii 316 resistant to acetaldehyde grow better in a medium with ethanol than their parent cultures. In their specific growth rate and alcohol dehydrogenase activity, 28.7-66.7% of such mutants are superior to any clone isolated in a non-selective medium. A medium containing ethanol and acetaldehyde (0.5 to 1.0% by volume) is proposed to select and isolate highly productive mutants.