Життєздатність Bifi dobacterium bifi dum 1за впливу гіпотермії, одноразового та повторних циклів заморожування-відтавання

Oksana Knysh,Valentina Polianska,Oleksandr Pakhomov,Antonina Kompaniets,Svitlana Zachepylo

doi:10.15407/cryo30.03.247

Abstract

The viability of bacteria of the Bifidobacterium bifidum 1 probiotic strain under hypothermia, single and repeated freeze-thaw cycles (thermal cycling) was studied. Samples of bifidobacterial suspensions were frozen immediately after isolation or after daily hypothermic storage in three ways to the final temperature of either (–23 ± 1) or (–196 ± 1)ºC. After slow freezing of the samples down to (–23 ± 1) ºC bigger quantitative losses of bifidobacteria were observed if compared with those after rapid freezing by a direct immersion into liquid nitrogen. Storage of the samples under hypothermia and a single freeze-thaw was accompanied with a strong inhibition of the daily growth of bifidobacteria biomass and an increased formation of biofilms. Ten-fold thermal cycling in the most unfavorable way for survival did not lead to the death of all cells in suspensions. Up to 35% of bifidobacteria remained viable. Indices of the bifidobacteria ability to enhance biomass remained at the level of 35%, and the ability to form biofilm was kept at the level of 43.7–65.5% of the corresponding indices for freshly isolated cells. Probl Cryobiol Cryomed 2020; 30(3): 247–255

Highlights

The viability of bacteria of the Bifidobacterium bifidum 1 probiotic strain under hypothermia, single and repeated freezethaw cycles was studied
The microbial suspension was frozen as follows: A – 50 ml samples in flasks were frozen to a final temperature (–23 ± 1) °С for four hours; B – 1.5 ml samples in cryovials were frozen to the final temperature (–23 ± 1)°С for one hour; C – 4.5 ml samples in cryovials were frozen by direct immersion into liquid nitrogen to проблеми кріобіології і кріомедицини problems of cryobiology and cryomedicine том/volume 30, No/issue 3, 2020
At the first stage of this research the effect of different freeze-thaw techniques on the content of viable bifidobacteria in suspensions of freshly isolated cells and the suspensions stored under hypothermia was studied

Summary

Introduction

The viability of bacteria of the Bifidobacterium bifidum 1 probiotic strain under hypothermia, single and repeated freezethaw cycles (thermal cycling) was studied. Samples of bifidobacterial suspensions were frozen immediately after isolation or after daily hypothermic storage in three ways to the final temperature of either (–23 ± 1) or (–196 ± 1)oС. Storage of the samples under hypothermia and a single freeze-thaw was accompanied with a strong inhibition of the daily growth of bifidobacteria biomass and an increased formation of biofilms. Indices of the bifidobacteria ability to enhance biomass remained at the level of 35%, and the ability to form biofilm was kept at the level of 43.7–65.5% of the corresponding indices for freshly isolated cells. Біфідобактерії – одна з важливих складових мікробної спільноти кишечника людини. The loss of bifidobacteria negatively affects the human health To restore their number in human body, the probiotic strains are traditionally prescribed as pharmaceuticals, food additives and fermented dairy products. A promising approach to correct the Надійшла 10.07.2019 Прийнята до друку 07.09.2020

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