Search

The authors obtained a stable variant of the L-forms of Bacillus subtilis capable of exponential growth of the minimal and synthetic medium. An electron-microscopic study of different stages of the L-form formation was carried out by the method of ultra-thin sections. A possibility was shown of the transfer of the L-form formation sign by the method of transformation. DNA isolation from the L-forms by soft lysis considerably facilitated and simplified the genetic analysis of the L-form formation by the transformation method.

A portion of the deoxyribonucleic acid sequences present in Streptococcus faecalis were absent in its stable L form. The remaining sequences were common to both forms.

Deoxyribonucleic acid base compositions were determined for 25 Mycoplasma strains and 6 L-phase variant strains. Values obtained correlated well with the results of other investigators.