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[Ion-exchanging ratio and membrane potential in the bacterium S. faecalis]
Biofizika
|May 1, 1982
Summary
Membrane potentials in S. faecalis remained stable across temperatures. Glycolysis involves an ion exchange of 2H+: Lac-: K+, suggesting a potential electrogenic pump.
Area of Science:
- Microbiology
- Biophysics
Context:
- Investigating cellular energetics in *S. faecalis*.
- Understanding the role of membrane potential in microbial metabolism.
Purpose:
- To measure membrane potentials (Δψ) in *S. faecalis*.
- To determine the ion exchange ratio during glycolysis.
- To explore the potential existence of an electrogenic pump.
Summary:
- Membrane potentials (Δψ) in *S. faecalis* were measured at -140 mV using TPP+-electrodes.
- Δψ values remained constant despite temperature changes from 37°C to 18°C.
- The ion-exchanging ratio during glycolysis was identified as 2H+: Lac-: K+, with 2H+ and Lac- liberated from the cell.
Impact:
- Provides insights into the bioenergetics of *S. faecalis*.
- Suggests the presence of a 2H+/K+ electrogenic pump in the bacterial membrane.
- Contributes to understanding microbial ion transport mechanisms.