卵形鲳鲹吸收利用配合饲料中植物油的肠道微生物的筛选

为了探讨肠道微生物在水产动物脂类代谢中的作用，提高水产动物对配合饲料中植物油的利用能力，本研究收集摄食豆油或亚麻籽油配合饲料的卵形鲳鲹(Trachinotus ovatus)幼鱼的肠道内容物，通过在培养基中添加尼罗红染液及混合脂肪酸底物的方法，从中筛选出一株能吸收亚油酸、亚麻酸的溶藻弧菌(Vibrio alginolyticus TO1)；通过观察三丁酸甘油酯(tributyrin)固体培养基中的水解圈及在液体培养基中添加油脂和溴甲酚紫(bromocresol purple)指示剂方法，筛选到一株能高产脂肪酶、降解豆油和亚麻籽油的哈维氏弧菌(Vibrio harveyi TO1).这些结果表明，鱼类肠道微生物能够响应配合饲料中的脂肪源，当用植物油替代配合饲料中的鱼油时，肠道中吸收、降解、利用植物油的弧菌的丰度增加，进而参与鱼体内的脂类代谢.

Isolation of intestinal microbes utilizing dietary vegetable oils in Trachinotus ovatus

In order to explore the roles of intestinal microbiota in lipid metabolism of aquatic animals and improve the ability of aquatic animals to utilize dietary vegetable oils in compound feeds, this study collected the intestinal contents of juvenile golden pompano (Trachinotus ovatus) fed diets with soybean oils or linseed oils, and then isolated a strain of Vibrio alginolyticus TO1 which can absorb linoleic acid and linolenic acid through adding Nile red dye and mixed fatty acid substrates to the culture mediums. Moreover, a strain of Vibrio harveyi TO1, which can produce high-yield lipase and degrade soybean oils and linseed oils, was also isolated by adding an indicator of bromocresol purple in the liquid mediums and a hydrolysis circle observed in the solid medium with tributyrin. These results indicate that the intestinal microbiota of fish can respond to the lipid sources of compound feeds fed to fish. When the dietary lipid source of fish oils was replaced with vegetable oils, the abundance of Vibrio in intestine will increase, which absorbs, degrades and utilizes vegetable oils, and then participate in lipid metabolism in fish.