Objectives: To optimize nisin production in Lactococcus lactis by using different aeration and fermentation strategies.
Results: The nisin titer and specific nisin production rate reached maximum values of 11,900 IU/ml and 4110 IU/g/h, respectively, in aerobic batch fermentation with glucose as C source. These values were higher than in anaerobic batch fermentation (10,700 IU/ml and 3260 IU/g/h, respectively). The maximum specific nisin production rates appeared earlier in aerobic batch fermentation, which suggests that nisin production is stimulated by aeration. Different fermentation strategies were compared: maximum nisin production (15,400 IU/ml) was achieved with fed-batch fermentation with a variable rate of feeding under aerobic conditions.
Conclusion: Nisin production can be stimulated by aeration, which goes against the typical conditions involving strict anaerobiosis.
Keywords: Aeration; Batch fermentation; Fed batch fermentation; Glucose; Lactococcus lactis; Nisin.