Characteristics of a cold-sensitive cell division mutant of Escherichia coli K-12.

Abstract

The culture of cold-sensitive division mutant, cs 2–29 consists of many normal cells and some filaments at 37°C. When an exponentially growing culture of cs 2–29 at 37°C was shifted to 20°C, the number of viable cells increased about 1.5-fold and the cells formed multinucleated filaments lacking septa. After the increase in optical density terminated at 20°C, normal cells separated from the end of filaments and the number of colony formers gradually increased. The number of viable cells of cs 2–29 increased normally at 25°, 30° and 37°C but not at 20°C in NBT medium.When chloramphenicol was added to the culture simultaneously with the temperature shift to 37°C after 6 hr of incubation at 20°C, the filamentous cells of cs 2–29 failed to divide. Strain cs 2–29 could divide at 20°C in NBT medium containing d-pantoyl lactone and also in semi-synthetic medium supplemented with sodium acetate as a carbon source.The mutant accepted both chromosomal and plasmid markers at reduced frequencies. The cs gene has been...