title: Effects of salinomycin and vitamin B(6) on the in vitro synthesis of lysine from the stereoisomers of 2,6-diaminopimelic acid by mixed rumen protozoa, bacteria, and their mixture.
abstract: An in vitro study was conducted to examine the effects of salinomycin (SL) and vitamin B(6) (pyridoxine hydrochloride) (B(6)) on the production of lysine from the three stereoisomers of 2,6-diaminopimelic acid (DAP-SI) by mixed rumen protozoa (P), mixed rumen bacteria (B), and their mixture (PB). P, B, and PB were isolated from the rumen of goats given a concentrate mixture and lucerne cubes, separately incubated for 12 h with and without DAP-SI (5 mM) as a substrate and SL (5 &mgr;g/ml) and/or B(6) (10 &mgr;g/ml) as additives. In P suspensions, SL and B(6) reduced the amount of DAP-SI by 2.1 times (p<0.001, where p is probability) and 19.9% (p<0.05), respectively, and also increased the production of lysine by 2.4 times (p<0.001) and 26.8% (p <0.05), respectively, during 12 h incubation. In B suspensions, the reductions of DAP-SI with a single addition of SL or B(6) were 8.5% (p<0.001) and 2.7%, respectively, and lysine production increased by 54.3 and 32.9% (p<0.001), respectively, during 12 h incubation. In PB suspensions, the reductions of DAP-SI were 21.9 and 11.7% (p<0.001) with a single addition of SL or B(6), respectively, and the production of lysine increased by 81.4 and 39.4% (p<0.001), respectively, during 12 h incubation. When SL and B(6) were added together to the P, B, and PB suspensions, lysine production further increased by 12.3, 21.3, and 12.4% more than the cases of adding SL only during 12 h incubation, respectively. SL and B(6) were demonstrated to enhance the production of lysine from DAP-SI by mixed rumen protozoa, mixed rumen bacteria and their mixture in this study.
authors.affiliation: Laboratory of Animal Nutrition and Biochemistry, Division of Animal Science, Miyazaki University, Miyazaki 889-21, Japan.
authors.forename: Ahmed M.
authors.initials: AM
authors.lastname: El-Waziry