摘要
为得到稳定高效降解亚硝酸盐的益生菌,通过菌株富集分离培养、菌株鉴定、发酵培养基优化等实验对菌株进行了分离、鉴定,对菌株降亚硝酸盐效果进行了分析,并克隆了亚硝酸盐还原酶基因。结果显示,从养殖池塘、污水处理厂等5处混合水体中分离、筛选出一株具有亚硝酸盐降解能力的菌株,命名为JY-1。菌株生理生化和16S rDNA序列分析显示,JY-1是大山芽孢杆菌(Bacillus gaemokensis);发酵培养基优化显示,JY-1的最适氮源和碳源分别是蛋白胨和葡萄糖。JY-1降亚硝酸盐效果分析显示,3 h JY-1可将水体中0.6 mg/L的亚硝酸盐降到0.0 mg/L。安全性评价检测显示,菌株JY-1菌落周围无溶血环出现,且高浓度JY-1(10^(9)CFU/mL)灌服尼罗罗非鱼对其无明显影响。克隆获得了JY-1亚硝酸盐还原酶基因,结合JY-1对水体中氨氮、亚硝酸盐、总氮等的影响实验,初步推测JY-1是通过酶降解途径把亚硝酸氮还原后将其移出水体的。本研究为制备高效降解亚硝酸盐的微生态制剂产品提供了重要原料。
In the present study,to isolate and screen a probiotic that degrades nitrite stably and efficiently,we carried out experiments on enrichment,isolation,culture,and identification of a suitable strain.Then,biological characteristics of the identified strain were determined through optimization of fermentation medium,analysis of nitrite degrading effect,and gene cloning of nitrite reductase.The strain was isolated and screened from five mixed water bodies,including aquaculture projects and wastewater treatment plants,and named JY-1.Additionally,the strain JY-1 was identified using 16S rDNA gene sequence analysis and physiological and biochemical characteristics.The results revealed strain JY-1 to be Bacillus gaemokensis.Optimization of fermentation conditions for sporulation of JY-1 strain indicated that the best carbon source for JY-1 was glucose and the best nitrogen source was tryptone.Analysis of the nitrite-degrading effect of JY-1 showed that JY-1 could degrade 0.6 mg/L nitrite in aquaculture water to 0.0 mg/L in 3 h.Moreover,the safety evaluation test suggested that no hemolysis was found,and the high concentration of JY-1(10^(9)CFU/mL)had no significant effect on the survival of Nile tilapia.Based on the results of experiments of gene cloning of nitrite reductase and the effect of JY-1 on ammonia,nitrite,and total nitrogen in water bodies,it is preliminarily speculated that enzymatic degradation,operated by JY-1,was the pathway through which nitrite was degraded and removed from water.In summary,this study provides an important basis for the preparation of microecological preparations with high efficiency in degrading nitrite.
作者
周敏
宁文
陈红菊
季相山
赵燕
ZHOU Min;NING Wen;CHEN Hongju;JI Xiangshan;ZHAO Yan(College of Animal Science and Technology,Shandong Agricultural University,Tai'an 271018,China)
出处
《中国水产科学》
CAS
CSCD
北大核心
2022年第2期284-294,共11页
Journal of Fishery Sciences of China
基金
山东省现代农业产业技术体系项目(SDAIT-13)
山东省农业重大应用技术创新项目(SD2019YY008)
山东省重点研发计划项目(2021CXGC010806).
关键词
大山芽孢杆菌
亚硝酸盐
养殖水体
分离
鉴定
Bacillus gaemokensis
nitrite
aquaculture water
isolation
identification
作者简介
周敏(1996-),女,硕士研究生,专业方向为水生生物学.E-mail:2978795597@qq.com;通信作者:赵燕,副教授,研究方向为水产健康养殖.E-mail:yzhao@sdau.edu.cn