Utilization of Xylose as an Alternative Carbon Source for Nisin Z Production by Lactococcus lactis IO-1

Lactococcus lactis IO-1 was able to use xylose as a carbon source for nisin Z production, whose yield was superior to that made with glucose under the same fermentation conditions. Nisin Z production was affected by several environmental factors, such as pH, temperature, initial xylose concentration and the addition of a cation. In view of possible future use, these factors have to be considered for designing the production process. From this study, the optimal condition for nisin Z production was obtained with 4% xylose at pH 6.0 and 37°C. Addition of 0.1 M CaCl₂ increased nisin Z production specifically, but not cell growth and acid production, which resulted in the maximum nisin Z activity of about 1.5 times that without CaCl₂.