IMPACT OF HYPOTHERMAL AND LOW TEMPERATURE STORAGE CONDITIONS ON VIABILITY OF IMMOBILIZED PROBIOTICS BIFIDOBACTERIUM BIFIDUM

Abstract

Dysbiosis is among the challenges the healthcare is facing now. This condition results from to the combined impact of a number of negative factors on the human body, and immune status weakening. The priority of current biotechnology is the elaboration of probiotics immobilized in gel particles that can be used to correct dysbiosis. Immobilization of probiotic cells in alginate gel granules protects them from the damaging effects of barrier functions of the gastrointestinal tract. The aim of the study was to investigate the effect of hypothermic and low-temperature storage on the viability of the probiotic Bifidobacterium bifidum immobilized in granules of alginate gel. Bacterial cells were immobilized in granules of unmodified gel (1% sodium alginate solution) and in granules of modified sucrose-milk-lactose gel. Granules with immobilized bacterial cells were placed into cryotubes. The samples kept at temperatures of +4, -12, -20, -80 and -196 ° C for 12 months (study period). It was found that storage at temperatures -80 and -196°C provided high viability of the probiotic throughout the study. During storage at temperatures of +4 and -12 ° C, the death of bacteria was observed in 1 – 3 months, depending on the composition of the gel particles, and at a temperature of -20°C the death occurs in 6-9 months. Conclusions: It has been established that the viability of B. bifidum culture cells immobilized in alginate gel granules is influenced by both storage temperature modes and gel modification by the introduction of sucrose-milk-lactose medium. At temperature ragnes of -80 and -196°C, immobilized bacteria do not die during the year (observation period). When storing at the temperatures +4, -12, -20°C, higher viability rates and longer shelf life of bifidobacterial cells were observed in samples of alginate gel granules modified with sucrose-milk-lactose medium. The study has shown that being kept at the low temperature values, B. bifida cells immobilized in unmodified and modified with sucrose-milk-lactose medium do not change their cultural and morphological properties.