COLONY ORGANIZATION OF CERTAIN BACTERIA WITH REFERENCE TO SPORULATION

Abstract

The course of sporulation within colonies of Clostridium acetobutylicum, Cl. pasteurianum, obligate anaerobes, and Bacillus acetoethylicum, a facultative anaerobe, was followed by means of stained sections. In B. a. sporulation is profuse only under aerobic conditions. Subsurface colonies of Cl. a. and B. a. are sporu-lated at the colony peripheiy only; in Cl. p. sporulation is profuse throughout the colony. In surface colonies of Cl. a. spores are confined to the central basal portion, while in Cl. p. the spores occur throughout the central portion. In B. a. sporulation tends to be localized at the upper surface of the colony under most conditions; when excess CaCO3 is added to the medium sporulation becomes profuse throughout the colony.