Production of milk, meat, and eggs enriched with conjugated linoleic acid by utilizing gastrointestinal bacteria

我们发现了一株新的丁核弧菌，该菌株具有极高的异构化亚油酸(LA)为共轭亚油酸(CLA)的能力，而不需要进一步加氢CLA。小鼠口服该菌株后，脂肪组织中共轭亚油酸比例增加，提示该菌株可用于提高猪肉、禽肉和禽肉中共轭亚油酸的含量。在牛身上，从肠道吸收的疫苗酸(VA)的增加可以增加肉和牛奶中的CLA含量，因为VA在体内被转化为CLA。我们还发现了一种新的B.fisolvens菌株，具有极高的将LA转化为VA的能力。由于大多数VA在瘤胃中被氢化为硬脂酸，我们试图通过允许VA被其他没有脂肪酸氢化活性的细菌吸收来保护VA不被氢化。结果，我们发现了几个细菌在没有氢化的情况下具有很高的吸收VA的能力。同时向瘤胃中引入VA产生菌和VA合成菌可能会增加瘤胃外排出的VA，从而增加VA的吸收。为了提高VA掺入菌摄取VA的能力，研究了一种脂肪酸转运体(酰基辅酶A合成酶)，但目前这项研究仍在进行中。为了有效利用纤维分离杆菌，刺激纤维分离杆菌在瘤胃和肠道中的生长是重要的。作为这样做的一种手段，如果B.fisolvens产生抑制周围其他细菌生长的抗菌物质，这是有益的。因此，我们寻找细菌素，并得到了一个结果，表明纤维分离杆菌产生细菌素样物质。

We discovered a novel strain of Butyrivibrio fibrisolvens having an extremely high ability to isomerize linoleic acid(LA) to conjugated linoleic acid(CLA) without hydrogenating CLA further. Oral administration of this strain to mice resulted in an increased CLA proportion in adipose tissue, suggesting that this strain can be used for increasing CLA content in swine meat and poultry meat and eggs. In cattle, an increase in vaccenic acid(VA) absorption from the intestine can increase CLA content in meat and milk, because VA is converted to CLA in the body. We discovered also a novel strain of B. fibrisolvens having an extremely high ability to convert LA to VA. Since most VA is hydrogenated to stearic acid in the rumen, we tried to protect VA from hydrogenation by allowing VA to be taken up by other bacteria that have no fatty acid hydrogenation activity. As a result, we found several bacteria having high ability to take up VA without hydrogenation. Simultaneous introduction of VA-producing bacteria and VA-incorporating bacteria to the rumen may increase VA in the efflux from the rumen, which leads to increased VA absorption.To improve the ability of VA-incorporating bacteria to take up VA, a fatty acid transporter(acyl-CoA synthetase) was examined, but this study is underway at present.For effective utilization of B. fibrisolvens, it is important to stimulate the growth of B. fibrisolvens in the rumen and intestine. As a means to do this, it is beneficial if B. fibrisolvens produces anti-bacterial substances that inhibit the growth of other surrounding bacteria. Thus, we sought bacteriocin and obtained a result suggesting that B. fibrisolvens produces bacteriocin-like substances.