THE INHIBITING EFFECT OF STREPTOCOCCUS LACTIS ON LACTOBACILLUS BULGARICUS

Abstract

If sterile milk is inoculated with equal amounts of Strep. lactis and L. bulgaricus, bulgaricus predominates. If inoculation of lactis is 2-3 times as great as bulgaricus, only slight development of bulgaricus occurs. This relation persists if the reaction is held at a p H favorable to both cultures. If a mixed milk culture is held for several days, bulgaricus finally develops. If a lactic culture is grown in broth in a collodion sac held in a flask of broth of the same composition, the broth in the flask becomes unfavorable to the growth of bulgaricus.