Effect of restrictive temperature on cell wall synthesis in a temperature-sensitive mutant of Bacillus stearothermophilus

Abstract

A temperature-sensitive mutant of Bacillus stearothermophilus, TS-13, was unable to grow above 58°C, compared to 720C for the wild type. Actively growing TS-13 cells lysed within 2 h when exposed to a restrictive temperature of 65°C. Peptidoglycan synthesis stopped within 10 to 15 min postshift before a shut down of other macromolecular syntheses. Composition of preexisting peptidoglycan was not altered, nor was new peptidoglycan of aberrant composition formed. No significant difference in autolysin activity was observed between the mutant and the wild type at 650C. Protoplasts of TS-13 cells were able to synthesize cell wall material at 520C, but not at 650C. This wall material remained closely associated 710C, with its temperature-sensitive mutant, TS-13, whose range is 37 to 580C. It has been shown (20, 35) that this temperature-sensitive mutant is unable to regulate both fatty acid and phospholipid metabolism in a normal fashion at high temperatures. Above the restrictive temperature of 580C, it undergoes lysis. We present here evidence that lysis in this mutant is caused by the cessation of cell wall synthesis due to 413 on August 1, 2020 by guest

Characterization of a novel thermophilic, cellulose-degrading bacterium Paenibacillus sp. strain B39

“…Such changes in lipid composition, which are critical for maintaining proper membrane fluidity under high temperature, have been expected for endospore‐forming bacilli to adapt to high growth temperature (Weerkamp and Heinen 1972; Rilfors et al. 1978; Mulks et al. 1980; Prado et al.…”

Surface films of Escherichia coli colonies

“…Vesicles were observed in the intercellular matrix, on the bacterial surface, and on the inner surface of colonial film. The existence of membrane vesicles was demonstrated in different bacterial species [12] and it was proposed earlier that this structure is derived from outer and/or inner membranes [13][14][15].…”

“…They apparently supply the membrane to the outer parts of the colony. The literature data indicate that similar membrane vesicles may also transport polysaccharides and 239 proteins [13][14][15]. Thus, these polysaccharides and proteins may contribute to the formation of the surface film amorphous layers.…”