Published on July 2012 | Microbiology

Enhancement of Nisin Production by Lactococcus lactis subsp. lactis MTCC 440 using a Novel Soya Permeate Medium

One of the biggest problems when producing nisin from lactic acid bacteria on an industrial scale is the high cost of the complex peptide sources of the specific commercial media. Improving nisin production through optimization of fermentation parameters would make nisin more cost-effective for various applications. In this work the possibility of using soya permeate as a substitute for commercial peptide sources was studied. The growth and nisin production by Lactococcus lactis subsp. lactis MTCC 440 was investigated in fixed volume batch fermentation on soya permeate, and MRS medium. Kinetic parameters and nisin production was higher to those obtained with bactopeptone and commercial media. Soya permeate was also supplemented with growth stimulating amino acids. Nisin biosynthesis is strongly dependent on the presence of a sulphur source, either an inorganic salt (magnesium sulphate or sodium thiosulphate) or the amino acids methionine, or cysteine. The amino acids serine, threonine and cysteine highly stimulate nisin production without affecting the final cell yield, indicating their precursor role during nisin biosynthesis.