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ATPase-dependent energy spilling by the ruminal bacterium, Streptococcus bovis
1Agricultural Research Service, USDA, Ithaca, NY.
Archives of Microbiology
|January 1, 1990
Summary
Streptococcus bovis exhibits energy spilling, a growth-independent heat production, primarily driven by proton influx and the F1F0 proton ATPase. This energy dissipation occurs even when bacterial growth is inhibited.
Area of Science:
- Microbiology
- Bioenergetics
- Bacterial Physiology
Background:
- Ruminal bacterium Streptococcus bovis utilizes glucose for energy.
- Bacterial heat production is typically proportional to growth rate.
- Understanding energy dissipation mechanisms is crucial for microbial metabolism.
Purpose of the Study:
- To investigate growth-independent energy dissipation (spilling) in Streptococcus bovis.
- To identify the key components involved in energy spilling.
- To elucidate the role of proton motive force in bacterial heat production.
Main Methods:
- Batch cultures of Streptococcus bovis grown with glucose.
- Treatment with chloramphenicol to inhibit growth.
- Incubation of stationary cells in nitrogen-free medium with glucose.
- Application of protonophores (monensin, TCS) and DCCD to modulate proton influx and ATPase activity.
Main Results:
- Growth-independent heat production (spilling) was observed in Streptococcus bovis.
- Proton influx facilitated by monensin and TCS significantly increased heat production.
- Dicyclohexylcarbodiimide (DCCD) effectively eliminated growth-independent heat production.
- Energy spilling was linked to proton influx and the F1F0 proton ATPase, not solely endogenous metabolism.
Conclusions:
- Energy spilling in Streptococcus bovis is a significant phenomenon.
- Proton influx coupled with F1F0 proton ATPase activity drives this energy dissipation.
- This mechanism provides insights into bacterial bioenergetics beyond growth-dependent processes.