Glycine betaine reverses the effects of osmotic stress on DNA replication and cellular division in Escherichia coli

• Published in: Archives of microbiology 1988, Vol.149 (3), p.232-239
• Main Author: MEURY, J
• Format: Article
• Language: English
• Subjects: Action of physical and chemical agents on bacteria; Bacterial Proteins - biosynthesis; Bacteriology; Betaine - metabolism; Biological and medical sciences; Cell Division; DNA Replication; DNA, Bacterial - biosynthesis; Escherichia coli; Escherichia coli - cytology; Escherichia coli - genetics; Escherichia coli - growth & development; Escherichia coli - metabolism; Fundamental and applied biological sciences. Psychology; Microbiology; Mutation; Osmolar Concentration; Osmotic Pressure; Potassium - metabolism
• ISSN: 0302-8933; 1432-072X
• DOI: 10.1007/bf00422010

The accumulation of glycine betaine to a high internal concentration by Escherichia coli cells in high osmolarity medium restores, within 1 h, a subnormal growth rate. The experimental results support the view that cell adaptation to high osmolarity involves a decrease in the initiation frequency of DNA replication via a stringent response; in contrast, glycine betaine transport and accumulation could suppress the stringent response within 1-2 min and restore a higher initiation frequency. High osmolarity also triggers the cells to lengthen, perhaps via an inhibition of cellular division; glycine betaine also reverses this process. It is inferred that turgor could control DNA replication and cell division in two separate ways. Glycine betaine action is not mediated by K+ ions as the internal level of K+ ions is not modified significantly following glycine betaine accumulation.