caa a22 4500 47574585X CHVBK 20180406123513.0 cr unu---uuuuu 170329e20000301xx s 000 0 eng 10.1007/s002849910037 doi (NATIONALLICENCE)springer-10.1007/s002849910037 Variations in the Ability of Ruminal Gram-Negative Prevotella Species to Resist Monensin [Elektronische Daten] [Todd R. Callaway, James B. Russell] Abstract.: Gram-negative, ruminal Prevotella strains (n = 15) differed greatly in their sensitivity to the feed additive monensin. Strains that were repeatedly transferred with sublethal doses tolerated more monensin than those that were unadapted, but growth experiments indicated that the sensitivity range was as great as 2000-fold. Prevotella bryantii B14 grew with monensin concentrations as high as 20 μM, but P. ruminicola H15a, D31d, 20-63, E40a, and D42f never initiated growth if monensin was greater than 0.01 μM. Washed cell preparations that were energized with glucose lost intracellular potassium when monensin was added, and potassium depletion could also be used as an index of monensin sensitivity. Adapted cells of P. bryantii B14 had a half-maximal potassium depletion constant (K d) of 3.2 μM, but the K d values of P. ruminicola strains H15a, D31d, 20-63, E40a, and D42f were less than 0.04 μM. Maximal potassium depletion (K max) values range from 90% to 40%, and monensin-adapted cells always had lower K max values than unadapted cells. A linear regression of log K d/K max versus percentage decrease in optical density divided by monensin concentration had an r2 of 0.75, and this regression indicated that potassium depletion from washed cells closely correlated with growth inhibition. P. bryantii B14 had a K d/K max ratio that was sevenfold greater than other Prevotella strains, and this result indicated that P. bryantii may be unusual in its ability to grow with very high concentrations of monensin. Springer-Verlag New York Inc., 2000 Callaway Todd R. Section of Microbiology, Cornell University, Wing Hall Ithaca, NY 14853, USA, US aut Russell James B. Section of Microbiology, Cornell University, Wing Hall Ithaca, NY 14853, USA, US aut https://doi.org/10.1007/s002849910037 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s002849910037 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Callaway Todd R. Section of Microbiology, Cornell University, Wing Hall Ithaca, NY 14853, USA, US aut NATIONALLICENCE 700 1- Russell James B. Section of Microbiology, Cornell University, Wing Hall Ithaca, NY 14853, USA, US aut Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer