The invention provides a
fermentation method for improving
titer of
nisin, which comprises the following steps of: performing seed culture on a
nisin seed solution, transferring the
nisin seed solution into a
fermentation culture medium, performing
fermentation culture, and achieving a manner of improving the
titer through a fermentation method of feeding, supplementing materials and introducing air. In the fermentation process, a 5% (g / L)
phytic acid solution is added in a fed-batch mode when the period is 10-16 h till fermentation is finished. Before the fermentation period is 14 hours, air is not introduced for culture, the
tank pressure is 0 Mpa, 0.01-0.05 vvm of air is introduced from 14 hours, and the
tank pressure is 0.03 Mpa until the fermentation is finished. The
phytic acid solution is supplemented in the middle and later periods of fermentation, the
metabolism speed can be controlled,
thallus oxidation death and autolysis are prevented, and the
biological value is indirectly improved. A trace amount of air is introduced, so that the generation of
lactic acid can be inhibited,
tricarboxylic acid circulation is properly enhanced, and the synthesis efficiency of precursor
amino acid is improved. Under the combined action of the two, the effects of controlling and prolonging the
primary metabolism time, reducing the yield of
lactic acid and obviously improving the
titer increase in the later period are achieved.