Indirect interaction in milk between proteolytic and isogenic non-proteolytic strains of Lactococcus lactis. I. Effect of pre-culturing by a non-proteolytic variant

The indirect interaction between proteolytic and lsogenic non-proteolytic strains of Lactococcus lactis was studied by performing sequential cultures in skim milk. After pre-culturing with a non-proteolytic strain for specifie periods of time, the milk was pasteurized, re-inoculated with a second strain and then re-incubated. This second strain was either the same non-proteolytic strain, or the parental proteolytic strain.