The use of crude cellular extracts of Lactobacillus delbrueckii ssp. bulgaricus 11842 to stimulate growth of a probiotic Lactobacillus rhamnosus culture in milk

The addition of the CCE to milk also promoted faster acidification in fermentations carried out without pH control, as did the addition of glucose (but not peptone). In these assays, CCE also increased viable counts in the fermented media. The β-galactosidase activity of the CCE, rather than its proteolytic activity, appeared to be the principal element in the improved acidification rates. The addition of heated CCE to milk failed to significantly improve the fermentation rate, thus confirming the enzymatic activity of the CCE to be the causative agent of its effectiveness.