Zellteilungsverhalten von Bacillus megaterium beim Übergang zu Kohlenstoffhunger

✍ Scribed by Dr. Sigrid Kretschmer

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 474 KB
• Volume: 11
• Category: Article
• ISSN: 0233-111X
• DOI: 10.1002/jobm.19710110205

✦ Synopsis

Abstract

In cultures of a sporulating strain of B. megaterium grown at different growth rates the rate of division and the distribution of cell length were measured electronmicroscopically. Samples were taken from two doubling times before carbon limitation through 2.5 hours after the shift down.

Contrary to the optical density, which increased exponentially until the carbon source was exhausted, the frequency of division changed 1–2 generations before. In fast growing glucose‐cultures the cells were longer than those in the slow growing arabinose‐cultures. These first mentioned cells became shorter already one doubling before the shift down by a transitory increase in division rate. No difference in length of growing and starvating cells was found with the arabinose‐culture. In all cultures the final decrease of the frequency of division also took place before the stationary phase was reached. This indicates that the initiation of division is more sensitive to carbon starvation than the net growth.

The shapes of the curves reflecting the distribution of cell size were nearly identical with growing and starving populations. Thus, cell elongation is inhibited by carbon exhaustion in all cells at the same time.

During the starvation period not all division septa were completed. 3–10% of the cells with in the populations remained uncompletely divided.