李张婵, 施慧, 许文军, 何杰, 谢建军, 王庚申, 汪玮. 大黄鱼内脏白点病病原拮抗菌的分离鉴定及生物学特性研究[J]. 南方水产科学, 2023, 19(3): 78-87. DOI: 10.12131/20220251
引用本文: 李张婵, 施慧, 许文军, 何杰, 谢建军, 王庚申, 汪玮. 大黄鱼内脏白点病病原拮抗菌的分离鉴定及生物学特性研究[J]. 南方水产科学, 2023, 19(3): 78-87. DOI: 10.12131/20220251
LI Zhangchan, SHI Hui, XU Wenjun, HE Jie, XIE Jianjun, WANG Gengshen, WANG Wei. Screening of antagonistic bacteria against visceral white-spots disease of Larimichthys crocea and preliminary study on its biological characteristics[J]. South China Fisheries Science, 2023, 19(3): 78-87. DOI: 10.12131/20220251
Citation: LI Zhangchan, SHI Hui, XU Wenjun, HE Jie, XIE Jianjun, WANG Gengshen, WANG Wei. Screening of antagonistic bacteria against visceral white-spots disease of Larimichthys crocea and preliminary study on its biological characteristics[J]. South China Fisheries Science, 2023, 19(3): 78-87. DOI: 10.12131/20220251

大黄鱼内脏白点病病原拮抗菌的分离鉴定及生物学特性研究

Screening of antagonistic bacteria against visceral white-spots disease of Larimichthys crocea and preliminary study on its biological characteristics

  • 摘要: 为实现大黄鱼 (Larimichthys crocea) 内脏白点病的生物防控,推进水产养殖用药减量,从健康大黄鱼肠道中筛选出对其内脏白点病病原菌——杀香鱼假单胞菌 (Pseudomonas plecoglossicid) 有拮抗作用的益生菌。采用琼脂扩散法筛选菌株,通过生理生化特征以及分子生物学分析,对菌株进行鉴定,并评价其溶血性、药敏性、安全性、产酶能力及抗菌广谱性。从健康大黄鱼肠道中初步分离出37株潜在益生菌,通过拮抗试验筛选出3株具有拮抗效果的菌株,分别命名为P1-17、P2-33和P3-11。通过生理生化特性及16S rRNA 测序分析,菌株P1-17和P2-33鉴定为贝莱斯芽孢杆菌 (Bacillus velezensis),菌株P3-11鉴定为粪肠球菌 (Enterococcus faecalis);溶血性试验和药敏试验结果表明3株菌均无显著溶血圈,且所含耐药因子较少,不具备潜在致病性;人工回感试验证实,3株拮抗菌对健康大黄鱼无致病性;抗菌谱测定结果表明,2株芽孢杆菌对溶藻弧菌 (Vibrio alginolyticus)、哈维氏弧菌 (V. harveyi)、美人鱼发光杆菌 (Photobacterium damselae) 等多种水产病原菌具有拮抗效果,同时2株芽孢杆菌具有产淀粉酶和蛋白酶的能力;而该株粪肠球菌只对杀香鱼假单胞菌有拮抗作用。研究结果可为后续大黄鱼肠道益生菌的筛选和应用提供科学依据。

     

    Abstract: In order to achieve the biological prevention and control of visceral white-spots disease of Larimichthys crocea, and promote the reduction of drug use in aquaculture, we isolated and screened the probiotics with an antagonistic effect on Pseudomonas plecoglossicid, which is a pathogen of visceral white spot disease in L. crocea, from the intestine of healthy L. crocea. The strains were screened by agar diffusion method, identified by physiological and biochemical characteristics and molecular biology analysis, and evaluated for hemolysis, drug sensitivity, safety, enzyme production ability and broad-spectrum antibacterial activity. Thirty-seven strains of potential probiotics were isolated and the three most potent strains were further characterized for their probiotic potential, named as P1-17, P2-33 and P3-11. The three most promising isolates were identified by sequencing the 16S rRNA gene and physiological and biochemical characteristics. Strains P1-17 and P2-33 were identified as Bacillus velezensis and P3-11 was identified as Enterococcus faecalis. According to the hemolytic test and disk diffusion method, none of the three strains had sigificant hemolytic rings, containing few drug resistance factors, so they had no potential pathogenicity. The result from the artificial infection safety test confirmed that these three strains of antagonistic bacteria had no pathogenicity to healthy L. crocea. The results of the antimicrobial spectrum show that two strains of Bacillus had an antagonistic effect on common aquatic pathogens such as Vibrio alginolyticus, V. harveyi and Photobacterium damselae. Moreover, two strains of Bacillus could produce amylase and protease, while the strain of E. faecalis only had an antagonistic effect on P. plecoglossicida. The study provides a scientific basis for the subsequent screening and application of intestinal probiotics in L. crocea.

     

/

返回文章
返回