Genetic improvement of technological characteristics of starters for fermented milk products

Possibility for improvement of technological characteristics of lactobacilli using mutations of resistance to rifampicin (rif r ) and streptomycin (str r ) was studied. Using starter model of Narine Lactobacillus acidophilus INMIA-9602 Armenian diet milk product, it was showed that a possibility for selecting strains with increased rate of milk fermentation and acid production is higher in Rifr and Strr mutants induced by nitrosoguanidine than in cultures sensitive to antibiotics. The milk products obtained using Rifr and Strr strains had high viscosity, improved texture, increased amount of alive cells and good organoleptic features.