РАЗРАБОТКА КОМПОНЕНТНОГО СОСТАВА ПИТАТЕЛЬНОЙ СРЕДЫ НА ОСНОВЕ ТВОРОЖНОЙ СЫВОРОТКИ ДЛЯ КУЛЬТИВИРОВАНИЯ ШТАММА BIFIDOBACTERIUM LONGUM B379M

Abstract

In the theoretical part of this paper, we discuss the role of natural intestinal microflora - in particular, bifidobacteria - in maintaining the homeostasis of the human body. We also explain the importance of the development of culture media for growing these important bacteria. In the experimental part, we present a step wise development of a culture medium composition for growing the Bifidobacterium longum B379M strain. Milk whey, a secondary raw material of the dairy industry containing numerous nutrients, seems to be a suitable basis for such a medium. The use of milk whey for these purposes also solves the problem of its rational utilization in the production of cottage cheese. The constituent components of the culture under development were selected taking into account the nutritional needs of the bacteria. The optimal amounts of these components were determined by comparing the logarithms of CFU concentrations in 1 mL of culture samples following a 24- hour incubation at 37°C and their active acidity values, which are considered to be indicative of the acid-forming ability of the bifidobacterium at its various cultivation stages. Pancreatic casein hydrolysate, peptone and yeast extract were used as sources of nitrogen; whereas inulin, lactose and glucose supplied the carbon requirement. A particular attention is paid to the creation of a neutral medium, which is necessary for bifidobacteria, by adding sodium citrate, ascorbic acid and a solution of phosphate buffer. The medium was also neutralized during the cultivation process using a sodium bicarbonate solution. As a result, the cell yield on the developed culture medium exceeded 109 CFU/cm3, which is sufficient for laboratory studies.