Augmentation of vaccenate production and suppression of vaccenate biohydrogenation in cultures of mixed ruminal microbes
Augmentation of vaccenate production and suppression of vaccenate biohydrogenation in cultures of mixed ruminal microbes
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DOI：
10.3168/jds.s0022-0302(06)72171-3
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发表时间：
2006-03-01
影响因子：
3.5
通讯作者：
Hino, T
中科院分区：
文献类型：
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作者：
Fukuda, S;Suzuki, Y;Hino, T
为了提高反式油酸（tVA）的瘤胃流出量，分离到一株能将亚油酸（LA）转化为tVA的溶纤丁酸弧菌（MDT-10）。当将菌株MDT-10添加到混合瘤胃微生物的分批培养物（活瘤胃细菌总数的1%）中时，LA向t-VA的转化大大增加; 3小时后，t-VA水平比对照高> 4倍。到10小时，所有的t-VA被氢化成硬脂酸。然而，当具有高掺入tVA能力的新的双岐杆菌（HF-11）菌株与MDT-10（瘤胃细菌总数的1%）一起添加时，10小时后的t-VA水平比单独使用MDT-10高6倍。这些结果表明，由MDT-10产生的t-VA被整合到HF-11细胞中，从而保护t-VA免受t-VA氢化微生物的侵害。在混合瘤胃微生物的连续培养中获得了类似的结果，其中同时添加HF-11和MDT-10使流出物中的t-VA量增加了2.5倍。MDT-10和HF-11在混合瘤胃微生物存在下似乎都容易生长。百分之六十二的t-VA纳入HF-11是以游离形式存在，而19，15，和3%，分别纳入单酰基甘油，甘油磷脂，和二酰基甘油馏分。由于这些脂质可以在小肠中消化，因此HF-11细胞中的大部分t-VA可能被吸收。因此，同时向瘤胃引入MDT-10和HF-11可能会增加t-VA的吸收量，并可能因此增加组织中t-VA向共轭亚油酸的转化。
To increase ruminal outflow of trans-vaccenic acid (tVA), a new strain of Butyrivibrio fibrisolvens (MDT-10) was isolated that has a great ability to hydrogenate linoleic acid ( LA) to t-VA. When strain MDT-10 was added to the batch cultures of mixed ruminal microbes (1% of the total number of viable ruminal bacteria), LA conversion to t-VA increased greatly; after 3 h, t-VA levels were > 4-fold higher than the control. By 10 h, all of the t-VA was hydrogenated to stearic acid. However, when a new strain of Bifidobacterium adolescentis (HF-11), which has a high capacity for incorporation of tVA, was added in conjunction with MDT-10 ( 1% of the total number of ruminal bacteria), t-VA levels after 10 h were 6 times higher than with MDT-10 alone. These results suggest that t-VA produced by MDT-10 was incorporated into HF-11 cells, resulting in protection of t-VA from t-VA-hydrogenating microbes. Similar results were obtained in a continuous culture of mixed ruminal microbes in which addition of HF-11 simultaneously with MDT-10 increased the amount of t-VA in the effluent 2.5-fold. Both MDT-10 and HF-11 appeared to grow readily in the presence of mixed ruminal microbes. Sixty-two percent of t-VA incorporated by HF-11 was present in the free form, whereas 19, 15, and 3%, respectively, were incorporated into monoacylglycerol, glycerophospholipid, and diacylglycerol fractions. Because these lipids can be digested in the small intestine, it is likely that most t-VA in HF-11 cells is absorbed. Thus, introduction of MDT-10 and HF-11 simultaneously to the rumen might increase the amount of t-VA absorbed and might consequently increase the conversion of t-VA to conjugated linoleic acid in tissue.