The enrichment of a ruminal bacterium (Megasphaera elsdenii YJ-4) that produces the trans-10, cis-12 isomer of conjugated linoleic acid
The enrichment of a ruminal bacterium (Megasphaera elsdenii YJ-4) that produces the trans-10, cis-12 isomer of conjugated linoleic acid
复制标题
DOI：
10.1046/j.1365-2672.2002.01610.x
复制
发表时间：
2002-01-01
影响因子：
4
通讯作者：
Russell, JB
中科院分区：
文献类型：
--
作者：
Kim, YJ;Liu, RH;Russell, JB
目的：从亚油酸 (LA) 中分离出产生反式 -10、顺式 -12 共轭亚油酸 (CLA) 的主要瘤胃细菌。方法和结果：从饲喂谷物的奶牛瘤胃内容物中提取的混合细菌富含 DL-乳酸和胰蛋白酶。与未富集的那些相比，它们产生了更多的反式 -10、顺式 -12 CLA（7 vs 2 mug mg Protein(-1) ，P < 0.05）。浓缩物中有大量大型球菌，可从洛杉矶产生反式 -10、顺式 -12 CLA。菌株YJ-4产生最多的反式-10、顺式-12 CLA(约7μg mg蛋白质(-1))，16S rDNA测序表明YJ-4是埃氏巨球菌菌株。埃氏巨球菌 T81 产生约。 4μg反式-10、顺式-12CLA mg蛋白质(-1)，而菌株B159、AW106和JL1产生<0.5μg mg蛋白质(-1)。 YJ-4 的反式 -10、顺式 -12 CLA 产量相对于细胞浓度（0-800 mug 蛋白 ml(-1) ）为一阶，但动力学相对于底物浓度不是一阶。结论：一些埃氏巨球菌菌株产生大量的反式 -10、顺式 -12 CLA。研究的意义和影响：反式 -10、顺式 -12 CLA 似乎会导致牛乳脂降低。饲喂补充有谷物和多不饱和脂肪酸的饲料，但以前从未分离出从洛杉矶产生反式 -10、顺式 -12 CLA 的主要瘤胃细菌。
Aims: To isolate predominant ruminal bacteria that produce trans -10, cis -12 conjugated linoleic acid (CLA) from linoleic acid (LA).Methods and Results: Mixed bacteria from ruminal contents of a cow fed grain were enriched with DL-lactate and trypticase. They produced more trans -10, cis -12 CLA than those that were not enriched (7 vs 2 mug mg protein(-1) , P < 0.05). Enrichments had an abundance of large cocci that produced trans -10, cis -12 CLA from LA. Strain YJ-4 produced the most trans -10, cis -12 CLA (approx. 7 mu g mg protein(-1) ) and 16S rDNA sequencing indicated that YJ-4 was a strain of Megasphaera elsdenii. Megasphaera elsdenii T81 produced approx. 4 mu g trans -10, cis -12 CLA mg protein(-1) while strains B159, AW106 and JL1 produced < 0.5 mug mg protein(-1) . The trans -10, cis -12 CLA production of YJ-4 was first order with respect to cell concentration (0-800 mug protein ml(-1) ), but kinetics were not first order with respect to substrate concentration.Conclusions: Some M. elsdenii strains produce significant amounts of trans -10, cis -12 CLA.Significance and Impact of the Study: Trans- 10, cis -12 CLA appears to cause milk fat depression in cattle fed diets supplemented with grain and polyunsaturated fatty acids, but predominant ruminal bacteria that produced trans -10, cis -12 CLA from LA had not previously been isolated.