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Updated: Jun 26, 2026
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Quantifying Tissue-Specific Proteostatic Decline in Caenorhabditis elegans
Published on: September 7, 2021
Rumen ciliated protozoa decrease generation time and adjust 18S ribosomal DNA copies to adapt to decreased transfer
J T Sylvester1, S K R Karnati, B A Dehority
1Department of Animal Sciences, The Ohio State University, Columbus 43210, USA.
Journal of Dairy Science
|December 26, 2008
Summary
Rumen protozoa growth rates adjust to feeding intervals, but monensin disrupts this response. Substrate availability triggers metabolic shifts, influencing protozoal cell division and growth.
Area of Science:
- Rumen microbiology
- Animal nutrition
- Protozoology
Background:
- Defaunation impacts ammonia and protein metabolism in ruminants.
- Protozoa suppression can negatively affect feed intake and digestibility.
- Optimizing protozoal growth is crucial for ruminant nutrition.
Purpose of the Study:
- To investigate how rumen protozoal growth responds to simulated changes in outflow rate.
- To evaluate the role of substrate availability and monensin on protozoal metabolic responses.
- To understand the relationship between protozoal growth, feeding, and substrate availability.
Main Methods:
- Simulated ruminal outflow rate by altering batch culture transfer intervals (3, 2, or 1 day).
- Assessed protozoal growth rate adjustments in response to transfer interval changes.
- Used real-time PCR to quantify protozoal 18S rRNA gene copies relative to cell numbers and constituents.
- Evaluated the effect of monensin on protozoal metabolic responses to feeding and starvation.
Main Results:
- Protozoal cultures rapidly adjusted generation times to match changes in transfer interval.
- Monensin consistently delayed the growth response to altered transfer intervals.
- Protozoal 18S rRNA gene expression indicated metabolic shifts in response to feeding and starvation.
- Monensin interfered with the utilization of consumed substrate, uncoupling it from metabolic responses.
Conclusions:
- Rumen protozoal growth is responsive to changes in outflow rate and substrate availability.
- Metabolic responses preparing for cell growth are initiated by substrate availability.
- Monensin disrupts normal substrate utilization and metabolic regulation in rumen protozoa.
- Cell division is regulated by substrate availability to prevent overgrowth.
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