摘要
为研究饲料中添加不同水平的复合菌剂(解淀粉芽孢杆菌,Bacillus amyloliquefaciens V4和胶红酵母,Rhodotorula mucilaginosa)对虹鳟(Oncorhynchus mykiss)幼鱼生长及消化道黏膜微生物菌群结构的影响,选用体重为(205.1±4.82)g的虹鳟幼鱼360尾,随机分为4组(每组3个重复,每个重复30尾),分别投喂基础饲料(C0)和3种添加水平为5×10~6/5×10~7 CFU/g(T1),1.5×10~7/1.5×10~8 CFU/g(T3),2.5×10~7/2.5×10~8 CFU/g(T5)的复合菌剂(B.amyloliquefaciens V4/R.mucilaginosa),实验周期42 d。研究结果发现饲料中添加复合益生菌对虹鳟的生长及存活有一定的促进和提高,T1比例的复合益生菌能够显著提高虹鳟的增重率和特定生长率、显著降低饲料系数(P<0.05),同时T1和T3比例添加显著降低虹鳟的死亡率(P<0.05);对其消化道黏膜细菌群落16S rDNA进行聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)指纹分析,结果表明:虹鳟胃黏膜和肠黏膜上微生物菌群种类存在差异;胃黏膜菌群DGGE图谱中分别检测到35.7±17.0(C0)、37.0±3.5(T1)、36.7±13.6(T3)、26.0±13.2(T5)条谱带,各处理组间谱带数目无显著差异(F=0.500,P=0.692),肠黏膜菌群DGGE图谱显示分别检测到23.3±5.8(C0)、22.3±3.2(T1)、16.7±8.0(T3)、24.7±7.4(T5)条谱带,各处理组间谱带数目也无显著差异(F=0.916,P=0.475);胃黏膜菌群多样性随着益生菌添加量增加,菌群多样性有升高趋势,但是在最高浓度组(T5)多样性降低,肠黏膜菌群多样性随着复合菌剂的添加,多样性指数持续降低,中浓度添加组(T3)多样性最低,但是随着添加浓度升高,呈现恢复和升高趋势(T5);基于所得PCR-DGGE指纹图谱中谱带丰度值数据的UPGMA聚类和PCA排序分析均显示胃黏膜微生物群落与肠黏膜微生物群落结构差异明显,大致分为两个不同的分支,胃黏膜和肠黏膜微生物菌群并没有按照不同处理组而有显著分化。以上结果表明解淀粉芽孢杆菌和胶红酵母复合添加能显著促进虹鳟的生长,提高存活率,外源益生菌添加对虹鳟消化道黏膜上优势菌群能产生一定影响,但并未对胃黏膜及肠黏膜菌群多样性产生显著影响,同时也未显著改变虹鳟肠黏膜微生物菌群结构,高比例添加降低消化道黏膜细菌数量及多样性风险。
Probiotic dietary supplementation has been widely used and has positive effects on the growth per- formance and host health of different fish species. Little attention is paid to its influence on fish gastrointestinal mucosal microbiota. A feeding trial was conducted to investigate the potential effects of probiotic compounds of Bacillus amyloliquefaciens V4 and Rhodotorula mucilaginosa on the growth performance and gastric and int- estinal mucosal microbiota of rainbow trout. A total of 360 rainbow trout with average body weight of （205.1±4.82） g were distributed in four equal groups in three replicates, and received one of the following experimental diets for 42 days： basal diet, basal diet supplemented with 5 × 106/5× 107 CFU/g （T 1, see tables 1 and 2）, 1.5 × 107/1.5 × 108 CFU/g （T3, see tables 1 and 2）, and 2.5×107/2.5×108 CFU/g （T5, see tables 1 and 2） of probiotic compounds. Significant improvement in weight gain ratio, feed conversion ratio, and the specific growth rate （SGR） was found in T1 diet supplemented with probiotic compounds. Significantly decreased mortality was found in T1 and T3 diets. Poly- merase chain reaction-denaturing gradient gel electrophoresis （PCR-DGGE） was applied to compare the gastroin- testinal mucosal microbiota of different treatments. In gastric mucosa, 35.7±17.0 （CO）, 37.0±3.5 （T1）, 36.7±13.6 （T3）, and 26.0±13.2 （T5） bands were found, with no significant differences （F=0.500, P=0.692）. In intestinal mucosa, 23.3±5.8 （CO）, 22.3±3.2 （T1）, 16.7±8.0 （T3）, and 24.7±7.4 （T5） bands were found, also with no significant diff- erences （F=0.916, P=0.475）. The bacterial diversity of gastric mucosa increased with increasing probiotic concen- tration, but it decreased in T5. However, the bacterial diversity of intestinal mucosa decreased with increasing probiotic concentration, which showed recovery in T5. Using both the unweighted pair-group method with arith- metic means （UPGMA） clustering and principal component analysis （PCA） ordination, we found that the micro- bial community structures of gastric mucosa and intestinal mucosa were different. No significant influences were found on bacterial diversity and microbial community structure of intestinal mucosa of rainbow trout with addition of probiotic compounds of Bacillus amyloliquefaciens V4 and Rhodotorula mucilaginosa. The potential risks of high concentrations ofprobiotics should be paid more attention.
出处
《中国水产科学》
CAS
CSCD
北大核心
2017年第4期746-756,共11页
Journal of Fishery Sciences of China
基金
国家自然科学基金资助项目(31472312
41306152
31402283)
现代农业产业技术体系建设专项资金项目(CARS-48)
国家科技支撑计划课题(2014BAD08B09)
关键词
解淀粉芽孢杆菌
胶红酵母
虹鳟
消化道黏膜菌群
PCR-DGGE
Bacillus amyloliquefaciens
Rhodotorula mucilaginosa
Oncorhynchus mykiss
gastric and intestinal mu- cosal microbiota
PCR-DGGE
