IDENTIFICATION OF LACTIC-ACID BACTERIA, Y EASTS AND ACETIC-ACID BACTERIA ISOLATED DURING MANUFACTURING PROCESS OF POT VINEGAR .3. STUDIES ON THE POT VINEGAR

Microorganisms used in an industrial scale process of pot vinegar were separated and grouped into lactic acid bacteria, yeasts and acetic ac id bacteria. Specific microorganisms belonging to each group were furt her classified and identified. Changes in the microbial flora of pot v inegar were examined during the manufacturing process. The results wer e as follows. Two hundred and thirty strains of lactic acid bacteria w ere separated and identified at 1, 5, 10, 20 and 30 days after mash wa s prepared. Lactobacillus plantarum was found to grow mainly for 5 day s after mash preparation. L. casei subsp. casei population increased s tarting on the 10th day to the 20th day. At 30 days after mash prepara tion, L. coryniformis subsp. coryniformis accounted for 68%, L. sake f or 20% and L. brevis for 12% of the lactic acid bacteria. Yeast strain s were identified at 5, 10, 20 and 30 days after mash preparation. Fro m the 110 strains identified, all strains were found to be Saccharomyc es cerevisiae, regardless of sampling day. Strains of acetic acid bact eria were identified at 45, 60, 75, 90 and 120 days after mash prepara tion. In the 150 strains identified, Acetobacter pasteurianus and A. a ceti occupied 65-81% and 18-35% of the population, respectively. From these results, with regard to the microorganisms on the manufacture of pot vinegar, changes in the microbial phases were revealed as follows . L. plantarum and L. casei lactic acid bacteria grow just after mash preparation, producing about 1% lactic acid. S. cerevisiae yeast incre ased because of the lactic acid present. After alcohol production, flo ating rice koji touching the pot began to fall gradually. A. pasteuria nus was then the main acetic acid bacteria with some A. aceti present, promoting acetic acid fermentation.