• Microbiology and Biotechnology Letters
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• v.14 no.3
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• pp.251-257
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• 1986

Optimum conditions for the protoplast formation and regeneration of Lactobacillus casei have been searched for. L. casei cells were converted to protoplast by treating with 10$\mu\textrm{g}$/$m{\ell}$ of mutanolysin in 20mM potassium phosphate buffer (pH6.8) containing 6mM CaCl$_2$, 6mM MgCl$_2$ and 1M sucrose. Maximum number of protoplasts was obtained when cells were taken from Tomochika's medium containing 0.5% glycine at the middle to late logarithmic growth phase. Regeneration was efficiently accomplished on the regeneration medium containing 6mM CaCl$_2$, 6mM MgCl$_2$, 0.8M sucrose and 10% of horse serum. The efficiently of the cell wall regeneration from protoplasts was 2-5% after 3-4 days of incubation at 3$0^{\circ}C$.