[Experiments with Bacillus thuringiensis protoplasts. I. Isolation of protoplasts and their reversion to bacillary form]

A method for protoplastization of crystal- and spore-forming Bacillus thuringiensis bacterian and consequent cell wall regeneration on a solid hypertonic medium is presented. Up to 50% of the protoplasts prepared were viable and formed colonies under special conditions; at the same time, less than 0,01% of the cells treated with lysozyme were resistant to the osmotic shock; bacterial autolytic system takes part in protoplasts formation. Electron microscopic studies of protoplasts and cells confirm the fact of cell wall removal and support the proposed mechanism of protoplast formation.