초록
Mixed culture of Saccharomyces cerevisiae and Acetobacter pasteurianus was carried out for high yield of acetic acid. Acetic acid production process was divided into three stages. The first stage was the growth of S. cerevisiae and ethanol production, fermentation temperature and aeration rate were controlled at 32<SUP>o</SUP>C and 0.2vvm, respectively. The second stage was the co-culture of S. cerevisiae and A. pasteurianus, fermentation temperature and aeration rate were maintained at 34<SUP>o</SUP>C and 0.4vvm, respectively. The third stage was the growth of A. pasteurianus and production of acetic acid, fermentation temperature and aeration rate were controlled at 32<SUP>o</SUP>C and 0.2vvm, respectively. Inoculation volume of A. pasteurianus and S. cerevisiae was 16% and 0.06%, respectively. The average acetic acid concentration was 52.51g/L under these optimum conditions. To enhance acetic acid production, a glucose feeding strategy was subsequently employed. When initial glucose concentration was 90g/L and 120g/L glucose was fed twice during fermentation, acetic acid concentration reached 66.0g/L.