异育银鲫'中科5号'产消化酶益生菌的筛选、鉴定及生物学特性研究  

Screening,Identification and Biological Characteristics Research of Digestive Enzyme Secreting Probiotics from Gibel Carp(Carassius auratus gibelio)CASⅤ

作　　者：于鹏 马晶晶[1] 成钰 张成硕 王凯[1] 周正海 YU Peng;MA Jing-Jing;CHENG Yu;ZHANG Cheng-Shuo;WANG Kai;ZHOU Zheng-Hai(Jiangsu Coastal Area Institute of Agricultural Sciences,Yancheng 224001,China;Jiangsu Zheng Yuan Chuang Hui Agricultural Science and Technology Development Co.,Ltd.,Yancheng 224700,China)

机构地区：[1]江苏沿海地区农业科学研究所,盐城224001 [2]江苏正源创辉农业科技发展有限公司,盐城224700

出　　处：《农业生物技术学报》2024年第8期1878-1889,共12页Journal of Agricultural Biotechnology

基　　金：中国盐城渔业高质量发展研究课题(YCSCYJ2021029)。

摘　　要：鱼类对饲料的低消化吸收率是造成饲料成本高昂、养殖利润低下的重要原因。异育银鲫(Carassius auratus gibelio)是我国当前最主要的鲫鱼养殖品种,本研究旨在从异育银鲫'中科5号'(CASⅤ)健康养殖体系中筛选出安全高效的产消化酶益生菌,从而改善“中科5号”对饲料的消化吸收能力,降低饲料成本。采用点种法从'中科5号'幼体及养殖水体中分离筛选出10株具有蛋白酶、脂肪酶和淀粉酶活性的菌株。对该10株菌的产酶能力进一步分析,并综合安全性(溶血性,药敏性和腹腔注射感染)试验结果,获得2株高效、无溶血性、对多数抗生素敏感且无致病性的菌株ZKW7和ZKF17。经16S rDNA序列分析,该2株菌均与枯草芽胞杆菌(Bacillus subtilis)和耐盐芽胞杆菌(B.halotolerans)具有最高的相似性。生物学特性分析结果显示,菌株ZKW7和ZKF17对氨氮(NH_(4)^(+))、亚硝酸氮(NO_(2)^(-))和硝酸氮(NO_(3)^(-))具有较强的降解活性;2株菌生长规律相似,6~16 h为对数生长期,菌株ZKW7的最适生长p H、盐度和金属离子分别是8、15和Fe^(2+),而菌株ZKF17在pH 7、盐度10~30以及Mg^(2+)存在的条件下生长最好;此外,该2株菌均具有一定的耐酸性、耐胆盐、耐肠液和耐胃液的特点。本研究筛选获得的2株安全、高效的产酶芽胞杆菌,可以作为异育银鲫“中科5号”的潜在益生菌。The low feed digestibility and absorption rate is an important reason for high feed cost and low profit of fish farming.Gibel carp(Carassius auratus gibelio)is one of the main current crucian carp breeding in China,the aim of this study was to screen safe and efficient probiotics which can secret digestive enzymes from healthy culture system of gibel carp CASⅤ,so as to improve feed digestion and absorption capacity of CASⅤand reduce feed cost.Ten strains with protease,lipase and amylase activities were isolated from CASⅤand pond water by spot inoculation method.Two highly efficient,non-hemolytic,sensitive to most antibiotics and non-pathogenic strains,ZKW7 and ZKF17,were obtained by further analysis of enzyme secretion ability and safety test(hemolysis,antibiotics susceptibility and intraperitoneal infection).Based on 16S rDNA sequence analysis,both strains had the highest similarity to Bacillus subtilis and B.halotolerans.The results of biological characteristics analysis showed that both strains had strong degrading activities for NH_(4)^(+),NO_(2)^(-)and NO_(3)^(-).The optimum growth conditions of ZKW7 were pH 8,salinity 15 and Fe^(2+)in culture medium,respectively.By contrast,the optimum growth conditions of ZKF17 were pH 7,salinity 10~30 and the presence of Mg^(2+).In addition,these 2 strains were resistant to acid,bile salt,intestinal fluid and succus gastricus to some extent.In the present study,2 strains of safe and efficient enzyme-producing Bacillus sp.were obtained,which could be used as potential probiotics and would be conducive to the healthy farming of C.auratus gibelio var.CASⅤ.

关 键 词：异育银鲫 产酶菌 安全性 生物学特性 

分 类 号：S917[农业科学—水产科学]