A process is provided for selective fermentation with microorganisms belonging to the Genus Pediococcus and having reduced or no phosphoenolypyruvate dependent sugar:phosphotransferase system. The microorganism is capable of fermenting a medium containing a metabolite which induces catabolite repression and a metabolite whose catabolism is inhibited by catabolite repression. The metabolite which induces catabolite repression may be selected from glucose and mannose and the metabolite whose catabolism is inhibited by catabolite repression may be selected from arabinose, xylose, galactose, sucrose, maltose, trehalose, lactose, and glycerin. The Pediococcus microorganisms used in this process are mutant strains designated Pediococcus halophilis I-1, having an accession number FERM BP-1303, and Pediococcus halophilis I-2, having an accession number FERM BP-1304.