Reversion of Lactobacillus lactis protoplasts.

More than 99% of L. lactis cells have been converted to protoplasts upon digestion of cell walls with mutanolysin (N-(acetyl)muramidase). Functional protoplasts were obtained even with the lowest level of the enzyme that was used (0.1 U.ml-1 of the cell suspension) and after incubation at 37 degrees C for 2 min. The regeneration of the polymerized cell wall appears to be induced by a cell homogenate of the same organism.