Maruschenko V. Analysis of freezing processes of yeast-like fungi Sacharomyces cerevisiae with taking into consideration the dispersion of cooling conditions in sample

Research object is a process of freezing of yeast-like fungi S. cerevisiae and its effect on frozen-thawed microorganism viability. The methods used in the study are volumometry, programmed freezing, thermography, light microscopy, Koch plate method, numerical solving of equations using PC. The aim of the study is to determine both the optimal cooling rate during freezing of yeast-like fungi S. cerevisiae in physiological solution and the effect of this regimen parameter variation in samples of cylindrical shape on their colony forming ability after freezing-thawing cycle. The results could be used in development of microorganisms' cryopreservation techniques in large volumes and in creating the devices for its realization. The novelty of the study is primarily determined distribution of cooling rates in containers of cylindrical shape, as well as the influence of this distribution on colony forming ability of the microorganisms; the study resulted in development of the algorithm of theoretical estimation of optimal cooling rate for microorganisms at the stage of suspension crystallization. The field of knowledge is cryobiology.