[Preparation and regeneration of protoplasts from Bacillus megaterium cells dried by sublimation]

Bacterial protoplasts are widely used in genetical research, for instance, in protoplasts fusion experiments and the transfer of heterologous DNA into bacterial cells. The usage of a new fresh grown culture of bacteria in every experiment restricts the reproducibility of the results preventing the technique becoming widespread. The use of antioxidants as components of stabilizing medium for sublimation drying of Bacillus megaterium cells supported cellular viability in bacterial culture. It also made possible preservation of such cellular fundamental properties as the ability to form protoplasts and regenerate the cell wall. Efficiencies of protoplasts formation and generation are similar for lyophilized and fresh grown cells. Cellular properties are conserved for 6 months of storage at least. Experiments with a lot of lyophilized biomass samples are highly reproducible. The potential of the technique was demonstrated in obtaining the hybrid Bacillus megaterium colonies by fusion of protoplasts derived from lyophilized genetically marked strains stored for up to 6 months.