摘要
[目的]本研究为了得到不同类型的四环素类抗生素高效降解菌株,扩大抗生素降解微生物菌种库,保护生态平衡及畜牧业的可持续发展。[方法]从采自污染场地中的土样进行四环素降解菌的筛选,采用形态观察和16S rRNA序列分析等对菌株进行鉴定;通过单因素实验研究不同条件对菌株Ly-1057降解四环素效率的影响,并对菌株Ly-1057进行扫描电镜观察。[结果]所筛选的菌株Ly-1507为阴沟肠杆菌(Enterobacter cloacae),对四环素降解的最佳时间是为7 d,具有较强的四环素耐受能力。对四环素降解的最优条件为:pH值为7、接种量为3%、可溶性淀粉为20mg·L^(-1)、酵母浸粉为20 mg·L^(-1)、底物浓度为80 mg·L^(-1)。菌株Ly-1057正常菌体外形清晰,表面粗糙,有大小不一的凹陷,增大了四环素与菌体的接触面积,为四环素与菌体的结合提供更多的位点。80 mg·L^(-1)四环素驯化的菌株细胞表面结构明显褶皱,产生形变,说明菌株Ly-1507吸附了一定量的四环素。[结论]筛选出了1株降解四环素的菌株—阴沟肠杆菌(Enterobacter cloacae),并对其培养条件进行优化,为其应用于污染土壤的四环素去除提供了坚实的理论基础。
[Objective]The main purpose of the current study was to obtain high-efficiency degrading strains of different types of tetracycline antibiotics,expand the library of antibiotic degrading microorganisms,and protect the ecological balance and the sustainable development of animal husbandry.[Methods]The tetracycline degrading bacteria were screened from soil samples collected from contaminated sites,and the strains were identified by morphological observation and 16S rRNA sequence analysis.The effects of different conditions on tetracycline degradation efficiency of strain Ly-1507 was investigated by single factor experiment,and the morphological observation of the strain Ly-1507 was conducted using by scanning electron microscope.[Results]The screened strain Ly-1507 was identified as Enterobacter Cloacae.The optimal time of tetracycline degradation was 7 d,indicating the strong tetracycline resistance.The optimal conditions for tetracycline degradation were as follows:pH value at 7,inoculation rate at 3%,the concentration of soluble starch at 20 mg·L^(-1),yeast extract concentration at 20 mg·L^(-1) and substrate concentration at 80 mg·L^(-1).The normal cell of strain Ly-1507 had a clear shape,rough surface and depressions of different sizes,which increased the contact area of tetracycline and thallus and provided more binding sites for tetracycline and thallus.The cell surface structure of the strain acclimated with 80 mg·L^(-1)tetracycline was obviously folded and deformed,indicating that the strain Ly-1507 absorbed a certain amount of tetracycline.[Conclusion]A tetracycline-degrading strain,Enterobacter cloacae,was screened out,and its culture conditions were optimized,which provided a solid theoretical basis for its application in the removal of tetracycline from contaminated soil.
作者
康宗利
刘爽
杨建
王新宇
靳雨松
杨玉红
Kang Zongli;Liu Shuang;Yang Jian;Wang Xinyu;Jin Yusong;Yang Yuhong(College of Biological Science and Technology,Shenyang Agricultural University,Shenyang 110866,China)
出处
《山西农业大学学报（自然科学版）》
CAS
北大核心
2022年第2期79-88,共10页
Journal of Shanxi Agricultural University(Natural Science Edition)
基金
国家重点研发计划项目(2018YFC1801200)。
关键词
四环素
降解菌
筛选
降解特性
Tetracycline
Degradation bacteria
Screening
Degradation characteristics
