| 罗非鱼无乳链球菌拮抗株的筛选及特性研究 |
| |
| 引用本文： | 王蕊,付维来,陈思,陈晶,易敢峰.罗非鱼无乳链球菌拮抗株的筛选及特性研究[J].水产科学,2019(4):465-472. |
| |
| 作者姓名： | 王蕊 付维来 陈思 陈晶 易敢峰 |
| |
| 作者单位： | 福建大北农水产科技有限公司;北京大北农科技集团股份有限公司 |
| |
| 基金项目： | 福建省科技计划项目——星火项目(2017S0027) |
| |
| 摘 要： | 自吉富罗非鱼养殖池塘水体、底泥和鱼体肠道中筛选无乳链球菌拮抗株。对其中1株抑菌能力最强的菌株LT3-1进行溶血性、形态、生理生化、16S rRNA基因序列测定,并进一步对其抑菌活性与发酵时间的关系、抑菌物质对温度的耐受性、产酶性能、降解亚硝酸盐性能、药物敏感性、安全性试验、攻毒试验进行研究。鉴定结果表明,菌株LT3-1为枯草芽孢杆菌,无溶血性。液体发酵16 h时,抑菌活性最强,抑菌圈平均直径为(25.30±0.57) mm。随温度的升高抑菌活性下降,但仍然存在,说明抑菌物质有耐高温特性。枯草芽孢杆菌LT3-1具有水解蛋白、淀粉和纤维素的能力。亚硝酸盐降解试验表明,枯草芽孢杆菌LT3-1菌液密度为10^5 cfu/mL时,6 h即可将亚硝酸盐质量浓度由2.5 mg/L降至0.03 mg/L,降解率达98.8%( P <0.05)。枯草芽孢杆菌LT3-1对检测的9种抗生素均敏感,罗非鱼接种密度为10^7 cfu/mL的枯草芽孢杆菌LT3-1菌液200 μL后,仍然存活且未有异常表现。动物攻毒试验表明,添加0.05%枯草芽孢杆菌LT3-1菌粉的试验组罗非鱼存活率提高20%,显著高于对照组( P < 0.05 )。综上所述,筛选自吉富罗非鱼肠道的枯草芽孢杆菌LT3-1能有效拮抗罗非鱼无乳链球菌,可以作为防治当地罗非鱼无乳链球菌病的良好菌种资源。
|
| 关 键 词： | 罗非鱼 无乳链球菌 拮抗 芽孢杆菌 生物学特性 |
Screening and Biological Characteristics of a Bacillus Strain with an Antagonistic Effect on Streptococcus agalactiae in Tilapia |
| |
| WANG Rui,FU Weilai,CHEN Si,CHEN Jing,YI Ganfeng.Screening and Biological Characteristics of a Bacillus Strain with an Antagonistic Effect on Streptococcus agalactiae in Tilapia[J].Fisheries Science,2019(4):465-472. |
| |
| Authors: | WANG Rui FU Weilai CHEN Si CHEN Jing YI Ganfeng |
| |
| Institution: | (Fujian Dabeinong Aquatic Science and Technology Co,Ltd,Zhangzhou 363500,China;State Key Laboratory of Direct-Fed Microbiology Engineering,Beijing Dabeinong Technology Group Co,Ltd,Beijing 100080,China) |
| |
| Abstract: | In this study,one of Bacillus strains with an antagonistic effect on Streptococcus agalactiae, the strain LT3-1 with strongest antagonistic effect,screened from pond water,sediment and intestinal tract of GIFT tilapia Oreochromis niloticus was identified by hemolytic,morphological,physiological and biochemical characteristics,and 16S rRNA gene sequencing. The relationship between antibacterial activity and fermentation time,tolerance of antibacterial substance to temperature,ability of enzyme production and nitrite degradation,drug sensitivity,safety and infection were also investigated in the strain LT3-1. Results showed that LT3-1 was identified as Bacillus subtilis without hemolysis and with the best antagonistic effect,the strongest antibacterial activity,with average inhibition diameter of 25.30 mm in 16 h fermentation. With the increasing temperature,antibacterial activity of LT3-1 was observed,even though decreased,indicating that antibacterial substance of LT3-1 can withstand high temperature. LT3-1 hydrolyzed casein,starch and cellulose,degrade nitrite from 2.5 mg/L to 0.03 mg/L within 6 h at 10^5 cfu/mL ( P <0.05),showing good ability of water purification. Besides,it was sensitive to nine kinds of antibiotics tested,and the safety test indicated that the tilapia injected with 10^7 cfu/mL LT3-1 were alive and no showed abnormal symptoms. The infection test revealed that there was 20% higher survival rate in the tilapia in 0.05% addition of LT3-1 than that in the control group ( P <0.05). Therefore, Bacillus subtilis LT3-1 has an obvious antagonistic effect on S. agalactiae in tilapia and can be an excellent candidate for the safe and effective control of S. agalactiae. |
| |
| Keywords: | tilapia Streptococcus agalactiae antagonistic Bacillus biological characteristics |
| 本文献已被 维普 等数据库收录！ |
|
