CAJ | 학술논문

从正常养殖的黄颡鱼肠道中分离得到218株细菌,通过产酶能力测试,对常见病原菌体外拮抗作用以及对抗生素敏感性试验筛选出1株益生菌HS140菌株.通过测定HS140菌株对黄颡鱼的致病性,并结合形态观察、生理生化试验和16S rRNA部分序列分析,对HS140菌株进行了分类鉴定.结果显示:HS140菌株具有很强的分泌蛋白酶、脂肪酶和淀粉酶的能力,能够抑制温和气单胞菌、迟缓爱德华菌和鳗弧菌的生长.HS140菌株对氨苄青霉素、磺胺异恶唑、先锋霉素VI等3种抗生素产生耐药性,对另外13种抗生素均敏感或中度敏感.急性毒性试验表明,浓度为1.0×10~8 cfu/mL的HS140菌悬液对黄颡鱼没有致病性.HS140菌株为革兰氏阳性可动杆菌,16S rRNA的部分序列分析显示HS140菌株与地衣芽孢杆菌(Bacillus licheniformis)具有99.3%的相似性,系统发育树上HS140菌株与地衣芽孢杆菌(FJ435674)聚为同一分支,结合形态观察和生理生化试验结果最终鉴定HS140菌株为B.licheniformis.
종정상양식적황상어장도중분리득도218주세균,통과산매능력측시,대상견병원균체외길항작용이급대항생소민감성시험사선출1주익생균HS140균주.통과측정HS140균주대황상어적치병성,병결합형태관찰、생리생화시험화16S rRNA부분서렬분석,대HS140균주진행료분류감정.결과현시:HS140균주구유흔강적분비단백매、지방매화정분매적능력,능구억제온화기단포균、지완애덕화균화만호균적생장.HS140균주대안변청매소、광알이악서、선봉매소VI등3충항생소산생내약성,대령외13충항생소균민감혹중도민감.급성독성시험표명,농도위1.0×10~8 cfu/mL적HS140균현액대황상어몰유치병성.HS140균주위혁란씨양성가동간균,16S rRNA적부분서렬분석현시HS140균주여지의아포간균(Bacillus licheniformis)구유99.3%적상사성,계통발육수상HS140균주여지의아포간균(FJ435674)취위동일분지,결합형태관찰화생리생화시험결과최종감정HS140균주위B.licheniformis.
Two hundred and eighteen bacteria strains isolated from intestinal tract of cultured Pelteobagrus fulvidraco were used for testing the producing zymogenicities of protease,lipase and amylase,the antagonistic against five common pathogenic bacterias and the antibiotic sensitivity.The toxicity of strain HS140 screened as potential probiotic for Pelteobagrus fulvidraco was evaluated.HS140 was identified according to its morphological,physiological and biochemical characteristics as well as homology analysis of 16S rRNA sequences.The results indicated that HS140 had high ectoenzyme-producing ability and could produce chemical substances inhibitor to Edwardsiella tarda,Aeromonas sobria and Vibrio anguillarum.HS140 was resistant to ampicillin,sulfamethoxazole,VI cefradine,but sensitive or medium sensitive to the other 13 kinds of antibiotics.It was safe for Pelteobagrus fulvidraco when they were challenged by a high immersion concentration of HS140 at 10~8 cfu/mL.Morphology observation showed that HS140 was gram-positive,rod,motile.The results revealed that strain HS140 comprised sequences more related to Bacillus licheniformis(99.3%) from partial 16S rRNA sequences.The identification showed that strain HS140 was Bacillus licheniformis by the way of morphology,biochemistry characteristic and 16S rRNA sequence homology analysis.