Enhanced cultivation technology for lacto- and bifidobacteria

Abstract

The aim of this work was to improve a cultivation technology of lactobacteria and bifidobacteria based on the optimal growth substrate, which ensures a preservation of basic biological properties of microorganisms. Seven variants of experimental nutrient media were prepared for cultivation of lactic acid bacteria. The growth properties of experimental nutrient media were studied using following strains: Lactobacillus plantarum 7, L. casei 27, L. plantarum 7-317, Bifidobacterium adolescentis 17 and B. adolescentis 17-316. The number of living microbial cells was determined by serial dilution methods. The composition of nutrient media for cultivation of lactobacteria, bifidobacteria and technological parameters of their cultivation were determined by the temperature of 37 ± 0.5°С. Acidity of a nutrient medium has pH value ranges from 6.5 to 7.5. A nutrient medium for cultivation of lactobacteria is proposed. Composition of new nutrient medium: lactose – 10.0-15.0%, sucrose – 5.0-10.0%, cystine – 0.01%, skim milk – up to 100.0%. It was established that the optimal nutrient medium for bifidobacteria accumulation composed of the following components (ratio of components, mass %): peptone – 7.0 ± 0.01, yeast autolysate – 4.0 ± 0.01, glucose – 1,5 ± 0.02, sucrose – 1.5 ± 0.01, cystine – 0.03 ± 0.01, ammonium citrate – 0.4 ± 0.03, potassium phosphate monosubstituted – 0.4 ± 0.02, MgSO4 – 0.04 ± 0.002, MnSO4 – 0.007 ± 0.002, sodium phosphate disubstituted – 0.4 ± 0.02, microbiological agar – 2.5 ± 0.04, sodium citrate – 0.8 ± 0.05, distilled water – up to 100%.