摘要
从正常养殖的鳗鲡肠道中分离得到477株细菌,通过对常见病原菌的拮抗试验和产酶能力测试筛选出47株细菌。通过对鳗鲡饲料培养基的利用能力从中筛选出19株细菌,鉴定分类后选择7株可能的益生菌进行鱼粉分解试验,筛选得到2株细菌,即A40209CDC4和A31009NA。最后测定这2株细菌对欧洲鳗鲡的毒力和对鳗鲡饲料的表观消化率。结果显示,在急性毒性试验中,试验剂量的细菌对欧洲鳗鲡无毒力,且能有效地提高对饲料的利用率,表明筛选出的2株肠道益生菌A40209CDC4和A31009NA具有良好的开发和应用前景。
The research of probiotics for aquatic animals is increasing with the demand for environment friendly aqnaculture. The probiotics were defined as live microbial feed supplements that improve health of man and terrestrial livestock. Most attempts to propose probiotics have been undertaken by isolating and selecting strains from aquatic environment. These microbes were vibrionaceae, pseudomonads, lactic acid bacteria, Bacillus spp. and yeasts. Some corrunercial products are referred to as probiotics used in eel culture, though they were commercial preparations devised for land animals. This paper focuses on selection of probiotics from bacterial strains which were isolated from intestinal tract of cultured healthy eels （ Anguillla anguilla and A. japonica）, then use the selected probiotics as supplement of eel feed. 477 bacterial strains of intestinal tract of cultured eel were used for testing the antagonistic against Edwardsilla tarda, Vibrio anguillarum Non O1 Vibrio cholera, Acinectobacter lwoffii, Aeromonas hydrophila and Aeromonas sobria etc. commonly eight strains of pathogenic bacteria of of cultured eel, and gelatinase, lipase, amylase, lecithinase, casease and chitinase production. 47 bacterial swains were selected as candidates. Then, by evaluating the BOD value of the 47 strains in the liquid eel-feed-medium, 19 bacterial strains which could effectively using eel feed as their nutrients for growth were selected as candidates. After identification, 5 strains as Pseudomonas cavie, P. stutzeri, P. fluorescens （ 2 strains）, Staphylococcus lentus were pathogenic bacteria to cultured eel, 5 strains were no identification, these isolations were abandoned. Selected one strain from two Bacillus subtilis isolations and two Bacillus pumilus isolations, combined with other isolations, 7 bacterial strains were selected as candidates. By tested the degrade fish meal and tested free amino acid of 7 candidates, strain A40209CDC4 and strain A31009NA were selected as probiotics for supplement of eel feed. By oral administration （A31009NA） and injection infection （A40209CDC4 and A31009NA） test, the results of acute toxicity to European eel showed that there were no toxicity to European eel in 7days at dosage 10^9CFU·mL^-1 concentration of strain A40209CDC4 and strain A31009NA. Strain A40209CDC4 and strain A31009NA used as supplement of formulated eel feed at dosage 10^6 CFU·g^-1, the test eel was cultured at 22 ± 1 ℃, 100% water changed daily for forty days, the digestibility of dry matter and crude protein increased 30.96 and 10.04 percentage of strain A40209CDC4 respectively, and the digestibility of dry matter and crude protein increased 42.96 and 13.11 percentage of strain A31009NA respectively. From all of test items, the selected isolations were suitable used as probiotics for eel. The exploration and application of the selected isolations using as supplement of eel feed were significant.
出处
《水产学报》
CAS
CSCD
北大核心
2006年第1期97-102,共6页
Journal of Fisheries of China
基金
福建省农业科技攻关计划重点资助项目(2002N018)
关键词
养殖鳗鲡
肠道菌群
益生菌
筛选
cultured eel
intestinal tract bacteria
probiotics
selection
