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Bacillus megaterium is the historical species name used for strain KM in the lysozyme wall-removal experiment.

The 1953 paper The isolation of protoplasts from Bacillus megaterium by controlled treatment with lysozyme by Claes Weibull (pp. 688–690, Figures 2–3) tested Bacillus megaterium strain KM. Apparatus included a Klett-Summerson colorimeter with a red filter and a Spencer no. 8 phase-contrast microscope. Lysozyme in phosphate buffer produced empty residual bodies; adding $0.2\mathrm{M}$ sucrose preserved granular spheres. Diluting their surroundings caused rapid osmotic lysis.

The same study compared untreated, boiled, lysozyme-exposed and sucrose-protected samples. Filled, stoppered tubes reduced damage from air exposure. After centrifugation, a Beckman DU spectrophotometer measured ultraviolet wave absorption of the separated liquid. Protected samples resembled untreated controls in releasing little ultraviolet-absorbing material; boiled and unprotected samples released much more. Later-growth cultures reduced spontaneous breakdown as a confounder.^[ref]

Together, the shape and release readouts support removal of mechanical protection while a permeability barrier persists. They do not establish unchanged selective permeability to every solute, long-term viability, or universal susceptibility.

An instructive extension of this experimental logic is a matched comparison: lysozyme present or absent, crossed with osmotic support present or absent. Keep starting material, buffer, observation interval and handling comparable; include a blank to distinguish optical effects of reagents from changes in the biological cells. Then dilute already formed protoplasts as a separate intervention. This separates access and wall removal from failure after removal. These are proposed controls for interpreting the mechanism, not additional reported results from the historical paper. A fall in optical signal alone cannot establish rupture: shape changes also alter scattering of light.