Conservation of Microorganisms of Biotechnological Interest

Thirty strains of microorganisms from the National Collection of Nonpathogenic Microorganisms (NCNM) were used as study objects (actinobacteria, bacteria, and micromycetes). Strains were assessed for viability after lyophilization using diverse lyoprotectants suitable for protection during freeze-drying, and for enzyme activity before and after lyophilization with amylase, catalase, cellulase, and lipase. Actinobacteria of genera Actinomadura, Actinoplanes, Micromonospora, Streptomyces, after lyophilization, showed minor changes. The viability after lyophilization ranged from 87.2% to97.9%. After lyophilization, bacteria of the genera Bacillus, Micrococcus, and Paenibacillus, showed that most strains retained their enzyme activity at the initial level, and the viability was on a larger scale, ranging from 76.4% to 95.6%. In this case, the main thing is that two-thirds of viable cells were preserved, which is sufficient for a more extended storage period. After lyophilization, Micromycetes represented by the genera Talaromyces and Trichoderma retained their initial enzyme activity. The survival rate of micromycete spores after lyophilization was very high, ranging from 93.7% to 99.2%, compared to the initial rate before lyophilization. Lyophilization of microbial strains from NCNM is efficient for preserving strains of biotechnological interest.