摘要
本实验旨在筛选对米尔伊丽莎白菌(Elizabethkingia miricola)有抑制作用的拮抗菌,并对其生长特性及其去除氨氮和亚硝酸盐的作用进行分析。实验采用平板对峙法从“稻蛙”养殖稻田土壤中分离到1株对米尔伊丽莎白菌有较强抑制作用的菌株X2。采用形态学特征观察和16s rDNA测序对X2进行鉴定,随后对X2在不同pH、盐度、温度等条件下的生长曲线进行了测定,以评估其环境适应性,并将X2接种于氨氮和亚硝酸盐培养基中,测定去除率以评估其去除氨氮和亚硝酸盐的能力。结合形态学特征及菌株16s rDNA序列分析,X2鉴定为侧孢短芽孢杆菌(Brevibacillus laterosporus)。结果显示:X2在pH 5~9、盐度5‰~50‰、温度20~40℃之间均能生长,最适pH、盐度、温度分别为7、5‰和35℃。这表明X2对环境的适应性较强,具有较强的耐酸碱性、耐盐性,适温性广等特性。X2在去除氨氮、亚硝酸盐方面也表现出了很强的能力,在X2接种浓度为5.0×10^(7) CFU/mL时氨氮的去除率最高,达到74.95%;接种浓度为5.0×10^(5) CFU/mL时亚硝酸盐的去除率最高,达到99.89%。结果表明,侧孢短芽孢杆菌X2对米尔伊丽莎白菌具有较强的拮抗作用,其环境适应能力也很强,同时具有较强的去除氨氮和亚硝酸盐的能力,可作为益生菌应用于蛙类养殖中防控米尔伊丽莎白菌感染和水质调控。
A strain X2 with strong inhibitory effect on Elizabethkingia miricola was isolated from the soil of rice-frog culture paddy field by plate confrontation method in this study to screen antagonistic bacteria which can antagonize pathogenic bacteria of E.miricola,and to analyze its growth characteristics and its effects on reducing ammonia nitrogen and nitrite nitrogen.X2 was identified by morphological observation and 16S rDNA sequencing analysis,and then the growth curve of X2 under different pH,salinity and temperature was determined to evaluate its environmental adaptability.X2 was inoculated in ammonia nitrogen and nitrite medium,and the removal rate was determined to assess its ability to remove ammonia nitrogen and nitrite.Combined with morphological characteristics and 16S rDNA sequence analysis,X2 was identified as Brevibacillus laterosporus.The growth results under different culture conditions showed that X2 could grow in the range of pH 5~9,salinity 5‰~50‰and temperature 20~40℃.The optimum pH,salinity and temperature were 7,5‰and 35℃,respectively.The results showed that X2 has strong adaptability to the environment.It had strong acid and alkali resistance,salt tolerance,wide temperature adaptability.X2 also showed a strong ability to remove ammonia nitrogen and nitrite.While the inoculation concentration of X2 was 5.0×10^(7) CFU/mL,the removal rate of ammonia nitrogen was the highest,reaching 74.95%.The removal rate of nitrite was the highest,reaching 99.89%whilethe inoculation concentration was 5.0×10^(5) CFU/mL.The results showed that B.laterosporus X2 had strong antagonism to E.miricola,strong environmental adaptability and strong ability to remove ammonia nitrogen and nitrite.It can be used as probiotics to prevent and control E.miricola infection and water quality regulation in frog culture.
作者
张虹
徐进
魏开金
徐滨
王丹
ZHANG Hong;XU Jin;WEI Kai-jin;XU Bin;WANG Dan(College of Fisheries and Life Science,Shanghai Ocean University,Shanghai 201306,China;Yangtze River Fisheries Research Institute,Chinese Academy of Fishery Sciences/Key Laboratory of Freshwater Biodiversity Conservation,Ministry of Agriculture,Wuhan 430223,China)
出处
《淡水渔业》
CSCD
北大核心
2023年第4期54-60,共7页
Freshwater Fisheries
基金
国家重点研发计划蓝色粮仓科技创新专项“多元复合型渔农综合种养技术与模式”课题资助(2019YFD0900305)。
