两株鱼源降脂乳酸菌的分离、体外筛选及分子鉴定  

Isolation,In Vitro Screening and Molecular Characterization of Two Fish-Derived Lactobacillus Strains

作　　者：崔聪聪 姜柳 王世锋[1] 时慧中 周永灿[1] 蔡岩[1] CUI Congcong;JIANG Liu;WANG Shifeng;SHI Huizhong;ZHOU Yongcan;CAI Yan(School of Marine Biology and Fisheries,Hainan University,Hainan Haikou 570228,China)

机构地区：[1]海南大学海洋生物与水产学院,海南海口570228

出　　处：《饲料工业》2024年第20期105-113,共9页Feed Industry

基　　金：国家自然科学基金地区基金项目[31860739];海南省自然科学基金高层次人才项目[320RC516]。

摘　　要：脂肪肝病是我国人工养殖鱼类中常见的营养性疾病,对水产养殖业造成很大的负面影响。为了筛选具有降脂作用的潜在乳酸菌,利用MRS琼脂培养基,从健康褐篮子鱼(Siganus fuscescens)和卵形鲳鲹(Trachinotus ovatus)肠道中分离得到52株乳酸菌。测定这些菌株的溶血性后得到35株不溶血乳酸菌菌株。经降脂活性复筛(测定菌株体外降胆固醇能力、体外降三酰甘油能力)后从中筛选得到2株具有降脂能力的潜在益生菌,随后测定了这2株菌株对人工模拟胃液、人工模拟肠液的耐受性、菌株的黏附能力(菌株表面疏水活性和自凝集能力)、胞外酶活性及颉颃病原菌活性,最终获得2株具有较强体外降脂能力的潜在益生菌(LZ8和F2),其中,菌株LZ8分离于褐篮子鱼肠道、F2分离于卵形鲳鲹肠道。经16S rRNA鉴定分别为乳酸乳球菌(Lactococcus lactis)和粪肠球菌(Enterococcus faecalis)。Fatty liver disease is a common nutritional disease in cultured fish in China,which has a great negative impact on aquaculture.In order to screen potential lactic acid bacteria with lipid-lowering effects,52 strains of lactic acid bacteria were isolated from the intestines of healthy Siganus fuscescens and Trachi⁃notus ovatus using MRS agar medium.After measuring the hemolysis of these strains,35 strains of nonhemolytic lactic acid bacteria were obtained.Two potential probiotics with lipid-lowering ability were screened after lipid-lowering activity rescreening(determination of cholesterol-lowering ability in vitro and triglyceride-lowering ability in vitro).Then the tolerance to artificial simulated gastric juice/pancreatic juice,the adhesion ability(surface hydrophobicity and self-aggregation),exoenzyme activity and antagonistic activity against pathogen bacteria were determined for these two strains.Finally,two potential probiotics(LZ8 and F2)with strong lipid-lowering ability in vitro were obtained.Strain LZ8 was isolated from the intestine of Siganus fuscescens and F2 was isolated from the intestine of Trachinotus ovatus.LZ8 and F2 were identified as Lactococcus lactis and Enterococcus faecalis,respectively,by 16S rRNA sequencing.

关 键 词：菌株筛选 降脂 乳酸菌 鱼源 分子鉴定 

分 类 号：S816.3[农业科学—饲料科学]