Maturation of the cell envelope-associated proteinase of lactococcus lactis.

Lactococci are of major economic importance for their use in production and preservation of cheese and other fermented milk products. The succes of this use depends on the fast production of lactic acid, which goes together with fast growth of lacctococci in milk. The amount of free amino acids and absorbable peptides in milk, however, is too small to sustain this fast growth. For this reason a proteolytic system, capable of degrading the milk proteins and thereby supplying the lactococcal cells of a nitrogen source, is indispensable. In chapter I, the general introduction, a brief overview is given on the lactococcal proteolyic system with the emphasis on the key enzyme in this system: the lactococcal cell envelope-located proteinase.