生态基对草鱼生长性能、肠道及水体微生物的影响

将无纺布生态基应用于草鱼养殖生产中,研究生态基对草鱼生长、免疫和养殖水质的影响,并利用PCR-DGGE技术分析了草鱼肠道和养殖水体微生物群落结构的动态变化。结果显示,实验组草鱼的末重、增重率均显著高于对照组(P0.05),饲料系数显著低于对照组(P0.05);草鱼血清碱性磷酸酶(AKP)、酸性磷酸酶(ACP)、超氧化物歧化酶(SOD)、溶菌酶(LSZ)活性水平均显著高于对照组(P0.05),诱导型一氧化氮合酶(iNos)和总一氧化氮合酶(tNos)均显著低于对照组(P0.05);除了在第30天时实验组TSS水平显著低于对照组(P0.05),整个过程挂设无纺布生态基对养殖水质参数影响不明显(P0.05)。PCR-DGGE检测结果显示:Cetobacterium somerae是对照组养殖水体和对照组草鱼肠道特异细菌;维氏气单胞菌是养殖水体和对照组草鱼肠道特异细菌,对照组养殖水体的分布明显比实验组丰富,在生态基中不存在;生态基的细菌群落构成和挂设生态基的实验组养殖水体相似性较高,最高时达到63%;绿弯菌占生态基细菌总量的10%左右,而在养殖水体中仅为5%。研究表明,生态基的应用有效促进了草鱼的生长,降低了饲料系数,提高了草鱼的非特异性免疫功能,降低养殖水体TSS浓度。生态基的应用改变了水体细菌群落组成,减少了养殖水体和草鱼肠道中一些条件致病菌的存在。

Effects of eco-substrates on growth performance,intestine and water bacterial community composition of Ctenopharyngodon idella

Eco-substrates technology is known to improve water quality and promote growth of breeding objects in aquaculture.In this study,a 30-day experiment was conducted to investigate the effectiveness of the non-woven eco-substrates for maintaining good water quality and promoting growth in Ctenopharyngodon idella of high density.At the same time,the fish nonspecific immunity,fish intestinal microbial composition,water microbial composition and microbial composition of eco-substrates were analysed in this research.Microbial communities were analyzed by using the PCR-DGGE(PCR-denaturing gradient gel)technology.In treatment group,the non-woven eco-substrates were placed in farming ponds with the density 0.32 m²/m³,which was produced by AquaMats Company.By the end of the test,final fish weight,weight gain and growth rate in treatment group were significantly higher(P<0.05)than control,feed conversion ratio between the two groups was opposite(P<0.05).The serum AKP,ACP,SOD and LSZ activities for treatment group were significantly higher(P<0.05)than control,but iNos and tNOS were significantly lower(P<0.05)in treatment group.At the end of the test,the TSS in treatment group was significantly lower(P<0.05)than control.However,no differences were found between control and treatment group with respect to other water quality parameters.Cetobacterium somerae and Aeromonas veronii were the specific bacteria in control grass carp intestine,which didn't exist in intestine of treatment group.Bacterial community composition similarity between eco-substrates and treatment group water was much higher,and peaked at 63%.Cetobacterium somerae was specific dominant bacteria in control water.Aeromonas veronii existed only in water,and the distribution in control was higher than that in treatment group.Chloroflexi accounted for about 10% of the total bacteria for eco-substrates,but only 5% in water.The results demonstrated that non-woven eco-substrates could be considered a good tool for grass carp,mainly by promoting growth,reducing feed conversion ratio,improving nonspecific immunity and reducing TSS of water.The use of non-woven eco-substrates changed water bacterial community composition,reduced the number of opportunistic pathogens in water and intestine of grass carp.