[Variable forms of Clostridium felsineum]

Variants of five types, differing in morphology of their colonies, resulted from spontaneous variability of Clostridium felsineum, the main agent involved in flax retting, when it was grown in a liquid medium and then on a solid medium. Morphological, cultural, and biochemical properties of the variants are described. The variants of the second and third types were less stable than those of the first type in the course of passages on growth media. The rate of spore formation was higher in the variants of the first type whereas the activity of pectolytic enzymes was greater in the variants of the second type.