Strain selection inKluyveromyces marxianus var.lactis for galactose production

After treatment with ethy1-methane sulfonate (EMS) mutants of Kluyveromyces marxianus var, lactis altered in galactose metabolism were obtained which were further imporoved by genetic recombination. Six types of mutants were detected. In batch culture strains with double mutations — either in galactokinase and uridyltransferase, or in galactokinase and epimerase- and which also had a galactose permease transformed lactose to galactose and galactitol. Strains with the same double mutations but no galactose permease completely hydrolyzed lactose to galactose and galactitol under continuous culture.