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Show THE UNIVERSITY OF UTAH RESEARCH POSTERS ON THE HILL 2013 TOXIN-DEGRADING BACTERIA: HERBIVOROUS RODENTS MAY PROVIDE A SOURCE OF NOVEL MICROBES FOR AGRICULTURAL HERBIVORES Ashley Stengel (Kevin Kohl, M. Denise Dearing) Department of Biology University of Utah TOXIN-DEGRADING BACTERIA: HERBIVOROUS RODENTS MAY PROVIDE A SOURCE OF NOVEL MICROBES FOR AGRICULTURAL HERBIVORES Ashley Stengel, Kevin D. Kohl, M. Denise Dearing Department of Biology THE UNIVERSITY OE UTAH 1 INTRODUCTION •Plants dissuade herblvory by producing toxic plant secondary compounds (PSCs), such as tannins. •Tannins bind proteins and digestive enzymes, preventing nutrient digestion. challenge, some herbivores host bacteria capable of degrading tannins. •We aimed to isolate and characterize Tannin- Protein Complex Degrading Bacteria (T-PCDB) from the feces of the desert woodrat (A/eofomo lepida), which specializes on the tannin-rich shrub, creosote bush [Larrea tridentata). XX, P Identified four species of tannin-protein complex degrading bacteria 'Bacillus subtilis 'Escherichia coll •Enterococcus faecalis 'Enterobacter cloacae CONCLUSIONS 'Neotoma lepida hosts tannin-protein complex degrading bacteria. This is noteworthy, as not all herbivores do. "Four species of bacteria are present, but only three show tannase activity. Tannase activity varies significantly between isolates and species. •These T-PCDB have also been isolated from other sources: E. faecalis from goats, E. coll from white-tailed deer, and Bacillus from soil. Tannase activity varied both within and between bacterial species. Larrea tridentata M E T H O DS T-PCDB Isolation Feces were plated on agar treated with tannic acid and incubated anaerobically. Colonies creating zones of clearance were further characterized. T-PCDB Identification W e performed Sanger sequencing on the 16S rRNA gene region. Sequences were compared with existing databases. Tannase Activity Isolates were incubated with methyl gallate, and production of gallic acid (a product of tannin degradation) was monitored using a colon m e trie assay. J L 1L Bacfcriansot* Agricultural herbivores, such as cattle, often encounter plants containing toxins. O n e class of toxins, tannins, bind to proteins and inhibit digestive enzymes from acting to liberate nutrients. In this way, tannins prevent optimal absorption of nutrients (1).To overcome this challenge, some herbivores host bacteria with the ability to degrade tannins (2-5). Currently, there is a push to find novel microbes capable of aiding animals in detoxifying these compounds (6). Therefore, w e aimed to isolate tannin-degrading bacteria from the desert woodrat (Neotoma lepida), a wild, herbivorous rodent that feeds largely on a tannin-rich shrub, creosote bush (Larrea tridentata). Woodrat feces were cultured on tannin-treated media, and bacteria capable of degrading tannins were further characterized with D N A sequencing (7). Results revealed that from 9 isolates, three species of tannin-degrading bacteria were present: Enterococcus faecalis, Bacillus subtilis, and Escherichia coli. Further characterization was performed through measurement of tannase activity (8). The activity of each isolate varied significantly between bacterial species as well as within a species. Ultimately, I hypothesize that these tannin-degrading bacteria facilitate the ingestion of tannin-rich plants by woodrats. Additionally, this research exemplifies h o w wild herbivores, such as the desert woodrat, provide an essential source of tannin-degrading microbes that could be introduced into domestic herbivores in order to improve agricultural practices. i_Li FUTURE QUESTIONS •How do dietary tannins affect the abundance of tannin-protein complex degrading bacteria? •Do T-PCDB actually Improve host performance on tannin-rich diets? Rottui norvegictn Bos primigenius |