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ARS Home » Midwest Area » Lexington, Kentucky » Forage-animal Production Research » Research » Publications at this Location » Publication #213990
Title: The Effects of Monensin on Amino Acid Catabolizing Bacteria Isolated from the Boer Goat Rumen

Author
item Flythe, Michael
item ANDRIES, KENNETH - KENTUCKY STATE UNIVERSITY

Submitted to: Small Ruminant Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2008
Publication Date: 1/21/2009
Citation: Flythe, M.D., Andries, K. 2009. The Effects of Monensin on Amino Acid Catabolizing Bacteria Isolated from the Boer Goat Rumen. Small Ruminant Research. 81. 178-181

Interpretive Summary: When ruminants consume feed, as much as half of the amino acid nitrogen can be lost due to microbial degradation in the rumen. Hyper ammonia-producing bacteria (HAB)are primarily responsible for nitrogen loss in sheep and cattle, and these organisms have been well characterized. However, little is known about microbial degradation of organic nitrogen in the caprine rumen. Moreover, many American meat goat ranchers use monensin to treat coccidiosis, but its effects on caprine rumen bacteria are undetermined. Five HAB isolates were obtained from the rumina of meat goats. They were all capable of degrading amino acids, but they varied in sensitivity to monensin. These results indicate that similar bacteria can occupy the hyper ammonia-producing guild in the bovine and caprine rumens. However, the ability to become monensin resistant does not appear to be a universal trait among this phylogenetic family of bacteria.

Technical Abstract: When ruminants consume feed, as much as half of the amino acid nitrogen can be lost due to microbial degradation in the rumen. Hyper ammonia-producing bacteria (HAB) are primarily responsible for nitrogen loss in sheep and cattle, and these organisms have been well characterized. However, little is known about microbial degradation of organic nitrogen in the caprine rumen. Five amino acid catabolizing isolates were obtained from the rumina of Boer goats, and the specific rates of amino acid deamination were >325 nmol mg cell protein-1 min-1. All five were Peptostreptococcaceae, but two of the isolates were most closely related to Peptostreptococcus anaerobius, while the other three were more closely related to Peptoniphilus indolicus. Monensin is used to inhibit the bovine amino acid catabolizing bacteria, and this ionophore depleted the intracellular potassium of the isolates in < 5 min. One-hour incubations with monensin decreased the specific activity of ammonia production, and the Peptoniphilus-like isolates were more sensitive than Peptostreptococcus anaerobius and closely related bacteria. However, growth experiments (16 and 40 h) revealed that at least two of the Peptoniphilus-like isolates had the ability to adapt to monensin.