Regulatory role for l-arginine in the utilization of amino acids by pig small-intestinal bacteria
Regulatory role for l-arginine in the utilization of amino acids by pig small-intestinal bacteria
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DOI：
10.1007/s00726-011-1067-z
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发表时间：
2012-07-01
期刊：
影响因子：
3.5
通讯作者：
Zhu, Wei-Yun
中科院分区：
文献类型：
--
作者：
Dai, Zhao-Lai;Li, Xi-Long;Zhu, Wei-Yun
我们最近报道了猪小肠中的细菌能迅速利用和代谢氨基酸。研究了L精氨酸对链球菌、大肠杆菌、克雷伯氏菌等纯细菌对AA利用的影响。以及来自猪小肠的混合细菌培养。在含0~5 mmoL/L精氨酸的AA厌氧培养液中，37℃培养3h，测定精氨酸对细菌利用AA的影响。用高效液相色谱仪分析培养基加细胞提取液中的氨基酸。结果表明，细菌对精氨酸的利用随着浓度的增加而增加，并改变了细菌中精氨酸转化为鸟氨酸和瓜氨酸的流量。纯菌株的谷氨酰胺净利用率随着精氨酸浓度的增加而增加。随着精氨酸的添加，链球菌对苏氨酸、甘氨酸、苯丙氨酸和支链氨基酸的净利用率增加(P<；0.05)。和克雷伯氏菌属(Klebsiella sp.)添加精氨酸降低了空肠或回肠混合菌对赖氨酸、苏氨酸、异亮氨酸、亮氨酸、甘氨酸和丙氨酸的净利用率(P<；0.05)。培养3h后，猪小肠细菌对天冬氨酸、天冬氨酸和丝氨酸的利用完全。总体而言，精氨酸的添加影响了小肠细菌中AA的精氨酸家族和丝氨酸和天冬氨酸家族的代谢，并降低了大部分AA在回肠混合菌中的利用。这些新的发现表明，精氨酸对猪的营养有益，部分是通过调节小肠微生物区系中AA的利用和代谢来实现的。
We recently reported that bacteria from the pig small intestine rapidly utilize and metabolize amino acids (AA). This study investigated the effect of l-arginine on the utilization of AA by pure bacterial strains (Streptococcus sp., Escherichia coli and Klebsiella sp.) and mixed bacterial cultures derived from the pig small intestine. Bacteria were incubated at 37A degrees C for 3 h in anaerobic AA media containing 0-5 mmol/L of arginine to determine the effect of arginine on the bacterial utilization of AA. Amino acids in the medium plus cell extracts were analyzed by high-performance liquid chromatography. Results indicated concentration-dependent increases in the bacterial utilization of arginine and altered fluxes of arginine into ornithine and citrulline in the bacteria. Net glutamine utilization increased in pure bacterial strains with increased concentrations of arginine. With the addition of arginine, net utilization of threonine, glycine, phenylalanine and branched-chain AA increased (P < 0.05) in Streptococcus sp. and Klebsiella sp., but decreased in E. coli. Net utilization of lysine, threonine, isoleucine, leucine, glycine and alanine by jejunal or ileal mixed bacteria decreased (P < 0.05) with the addition of arginine. Complete utilization of asparagine, aspartate and serine were observed in pig small-intestinal bacteria after 3 h of incubation. Overall, the addition of arginine affected the metabolism of the arginine-family of AA and the serine- and aspartate-family of AA in small-intestinal bacteria and reduced the utilization of most AA in ileal mixed bacteria. These novel findings indicate that arginine exerts its beneficial effects on swine nutrition partially by regulating AA utilization and metabolism in the small-intestinal microbiota.