Thermally caused filament formation in the psychrophile Bacillus insolitus

The formation of filaments by cells of the psychrophile, Bacillus insolitus, occurred at 30C but not at 20C. Determination of the distribution pattern of the lengths of cells grown at 20 and 30C showed that the number of longer cells continually increased at 30C up to about 12 h of incubation when 83% of the cells grown at 30C were at least 3 times as long as 87% of the cells grown at 20C. The synthesis of DNA corresponded to the amount of growth which occurred at 30C as well as at 20C, indicating that the cell elongation was not caused by the prevention of DNA synthesis at the higher temperature. The fact that the filaments were found to be multinucleated supported this conclusion.