Microorganisms present in the unfermented grains of millet at the Initial stage of steeping and after sieving at the initial stage of souring for the preparation of kamu were moulds (Aspergillus versicolor, Penicillim nigricans and Rhizopus stolonifer), bacteria (Pediococcus pentosaceus and Lactobaclllus plantarum) and a yeast (Saccharomyces cerevisiae). Only the bacteria and yeast persisted to the end of the steeping period. These, together with another yeast, Candida krusel, brought about the final souring of kamu.