Lyophilization of Pathogenic Microorganisms Strains on Freeze-Drying Modules of Different Type, and Quality Assessment of the Preparations Obtained

Abstract

Objective of the study is to evaluate applicability of different freeze-driers for lyophilization of pathogenic microorganisms of bacterial origin, and to perform comparative analysis of the quality of the strain formulations obtained using these devices.

Materials and methods. Four strains of pathogenic microorganisms, belonging to different species and applied as test ones for quality assessment of nutrient media, have been utilized as controls. Their lyophilization has been conducted on four different modules for sublimation, collector- and chamber-type. The quality of lyophilized strain formulations obtained has been evaluated via determination of their cell viability, as well as with the help of rapid survivability test on lyophilized bacterial cultures (thermo-stability assay).

Results and conclusions. Specified are the conditions for lyophilization of collection test-strains of pathogenic bacteria, falling under the category of the III–IV groups of hazard, using collector devices of the new generation, Martin Christ Alpha 1-4 LDplus and Heto Power Dry. Carried out has been comparative analysis of viability, survivability and prognosticated terms of storage for the strain preparations obtained with the help of the mentioned above modules and the like, lyophilized on the instrument based on K.E. Dolin technology and programmable drier of the chamber type, Martin Christ Epsilon 2-6D. It is revealed that microorganism preparation lyophilized on different sublimation devices are characterized with high viability of the contained bacterial cells and have prognosticated storage terms of 4–105 years, depending upon the microorganism species and the type of freeze-drier utilized.