[Interaction of E. coli cells with ascorbic acid and sodium nitrite studied by ESR method]

Area of Science:

• Microbiology
• Biochemistry
• Cellular Metabolism

Background:

• Ascorbic acid (vitamin C) is a known regulator of cellular metabolism.
• Nitric oxide (NO) plays crucial roles in various biological processes.
• Escherichia coli (E. coli) is a model organism for studying bacterial metabolism.

Purpose of the Study:

• To investigate the effect of ascorbic acid on nitric oxide production in E. coli.
• To explore the mechanism of NO generation and its detection.
• To understand ascorbic acid's role in cellular energy supply under hypoxic conditions.

Main Methods:

• Electron Paramagnetic Resonance (EPR) spectroscopy was used to detect Fe-S-NO centers.
• E. coli cultures were incubated with ascorbic acid under both anaerobic and aerobic conditions.
• Sodium nitrite formation was measured under aerobic conditions.

Main Results:

• EPR spectroscopy confirmed the generation of nitrosyl-iron-sulfur centers (Fe-S-NO) in E. coli under anaerobic conditions with ascorbic acid.
• Sodium nitrite was detected in E. coli cultures incubated with ascorbic acid under aerobic conditions.
• Ascorbic acid appears to support cellular energy metabolism during hypoxia.

Conclusions:

• Ascorbic acid induces nitric oxide production in E. coli.
• The Fe-S-NO signal indicates a specific metabolic pathway activated by ascorbic acid.
• Ascorbic acid may play a protective role in cellular energy homeostasis under oxygen-deficient environments.