SOME NEW OBSERVATIONS ON L FORMS OF BACTERIA,

Abstract

Surface growth of L forms in liquid media, as descr. by Tulasne, was obtained from 2 Proteus strains. With 15 other strains, such growth was not obtained. The floating growth is similar in many respects to the 3B cultures, but its ability to return to bacterial form is greatly diminished or entirely lost. The morph. of the 3 different L type cultures obtained from Proteus, the 3A, the 3B and the floating culture, is similar, but the nutritional requirements, rate of growth and tendency to resume bacterial form differ considerably. The L type cultures isolated from an unidentified bacterium are, immediately after isolation, intermediary between the 3A and 3B types. The colonies correspond in growth and appearance to the 3A type, but the bacterium reappears in some of the large bodies. The bacterium itself presents a remarkable spontaneous variability. It grows like a small bacillus or like an actinomyces or in the L form. The L forms do not represent a single well-characterized variant but a group of variants having a common morph. but otherwise varying considerably in their differences from the parent bacteria.