Strain Balance of multiple Strain Lactic Streptococcus Concentrated Cultures

The balance among strains of lactic streptococci in frozen concentrated cultures varied from that of corresponding conventional milk grown starters. The observations concerning strain balance were based on responses of the cultures to specific bacteriophages. If the bacteriophages affected the concentrated and conventional eultures differently, it was assumed that an alteration in strain balance had occurred. The alterations in strain balance may be partially responsible for variations in culture activity when comparing the acidproducing ability of the concentrated cultures to that of milk cultures. The strain balance of cultures grown in a broth medium with the pH automatically controlled at pit 6.0 differed from that of the same cultures: grown in milk. The composition of the growth medium was responsible for altering the strain balance rather than growth with automatic pit control.