Association of the probiotic cultures Lactobacillus reuteri and Lactobacillus helveticus for development of the bacterial concentrate

In order to increase production volumes of fermented milk products with probiotic properties it is advisable to look for new probiotic strains and work out functional products based on these strains. Lactobacillus reuteri is considered to be one of such strains. Lactobacillus reuteri slowly grows in milk, that’s why it is reasonable to cultivate it together with probiotic microorganism Lactobacillus helveticus which is more active in proliferation rate in milk. For mutual cultivation the strain Lactobacillus helveticus NK1 with low acidifying activity has been chosen. Cultivation in the sterile milk was carried out till the coagulum formation. Coagulation time was 5,5 hour when 3 % of Lactobaccilus reuteri and 3 % of Lactobacillus helveticus were added and 4 % of Lactobacillus reuteri and 2 % of Lactobacillus helveticus NK1 were introduced. When 4,5 % of Lactobacillus reuteri and 1,5 % of Lactobacillus helveticus NK1 were used and when 5 % of Lactobacillus reutei and 1 % of Lactobcillus helveticus NK1 were added coagulation time was 6 hours. In all samples quantity of the Lactobacillus helveticus NK1 cells was 1,1 • 108cfu/cm3 and Lactobacillus reuteri - 1 •107 cfu/cm3. In further studies in the nutritive media MRS inoculate Lactobaccilus reuteri prepared in the nutritive media MRS-broth was added in the quantity 5.5 и 5,9 % and inoculate Lactobacillus helveticus NK1 prepared in the sterile skim milk in the quantities 0,5 и 0,1 % correspondingly in order to receive quantity of inoculate introduced 6 %. Cultivation was carried out in fermenters. Quantity of the cells Lactobacillus helveticus NK1 at introduction of 0,5 % reached 7,8 •109 cfu/cm3 and 6,2 •109 cfu/cm3 at 0,1 %, Lactobacillus reuteri - 2 •108 cfu/cm3 when 5,5 % added and 3 •108cfu/cm3 at 5,9 % addition.

Lactobacillus helveticus, Lactobacillus reuteri, probiotic microorganisms, Lactococcus nelveticus, Lactococcus reuteri, mutual fermentation, nutritive media MRS