Action of cryoprotectors glucose, trealose and quitosan in maintaining viability of Escherichia coli, Saccharomyces cerevisiae cells after lyophilization

Abstract

Lyophilization is considered one of the safest techniques for acquiring stability of culture strains. For this process, cryoprotectants, which are substances that protect cell structures during the period of freezing, thawing and dehydration, may be used. The objective of the present work was to evaluate the performance of glucose, trehalose, and chitosan as cryoprotectants for Escherichia coli e Saccharomyces cerevisiae. For statistical treatment, ANOVA and Tukey’s test were used with the software Bioestat, version 5.3. For Escherichia coli Trealose presented better performance after lyophilization, but none of the treatments proved to be effective in prolonging viability up to 60 days of storage. For Saccharomyces cerevisiae all treatments were satisfactory throughout the 60 days evaluated.

Key words:
Conservation; Stability of strains; Lyophilization; Microorganisms