摘要
通过对近海沉积物进行微生物培养,分离鉴定了两株好氧反硝化细菌MD5和MD8,研究其在有氧条件下的反硝化能力及其相关影响因子.菌株形态、16S rRNA序列比对、系统发育分析及亚硝酸盐还原酶基因(nirS)结果显示,菌株MD5为一株盐单胞菌属Halomonas细菌,菌株MD8为一株产碱杆菌属Alcaligenesx细菌,其Gen Bank注册号分别为KM362826和KM406394.MD5和MD8在有氧条件下都具有硝化和反硝化的能力,在以NH_4^+-N作为唯一氮源的能力测试中,可分别达到81%和88.3%的去除能力;在以NO_3^--N为唯一氮源的能力测试中,可分别达到85.3%和92.1%的去除能力;在NH_4^+-N和NO_3^--N都存在的条件下,总无机氮(DIN)的去除率达到72%和76.8%.pH值、盐度和碳氮比(C/N)等因子对菌株MD5和MD8的DIN、NH_4^+-N和NO_3^--N的去除能力具有不同程度的影响.如低pH值(5.5-6.5)条件下,MD5和MD8的NH_4^+-N和NO_3^--N去除率受到显著抑制(P<0.05),其最佳pH值范围为7.5-8.5;在盐度为10-30 g/L的范围内,MD5对NH_4^+-N和NO_3^--N的去除率随着盐度的增长而增加,而MD8的最佳盐度范围稍低于MD5(20-25 g/L);在C/N低于6的条件下,MD5和MD8的NH_4^+-N和NO_3^--N的去除率都显著降低(P<0.05),但MD5比MD8表现出较低的C/N适应范围(8-10).以上研究表明,MD5和MD8在有氧培养条件下具有较强的硝化-反硝化能力,可应用于海水养殖池塘养殖废水的处理,具有良好的应用潜力.
In this study, we isolated strains MD5 and MD8 of nitrifying-aerobic denitrifying bacteria from intertidal sediments using microbial culture method, identified their biology taxonomy, and tested the ability of nitrogen removal. The morphology, 16 S rRNA sequencing and functional gene（nirS） results identified MD5 and MD8 as Halomonas and Alcaligenesx respectively with Gen Bank sequence number of KM362826 and KM406394. Both strains had nitrogen removal ability under aerobic condition. In the experiment with ammonium as the sole nitrogen resource, the nitrogen removal efficiency was up to 81% in MD5 and 88.3% in MD8. While in the experiment with nitrate as solo nitrogen resource, the efficiency reached 85.3% and 92.1% respectively. In experiment with the combination of ammonium and nitrate, the total removal rate reached 72% and 76.8% respectively. The pH, salinity and C/N ratio influenced to different degrees the removal ability of the two strains for NH_4＋-N, NO_3--N and dissolved inorganic nitrogen（DIN）. For instance, the removal abilities of MD5 and MD8 were significantly inhibited（P 0.05） at pH of 5.5-6.5, and the optimum pH was 7.5-8.5; the nitrogen removal ability of MD5 increased with the salinity within the range of 10-30, whereas MD8 reached its high removal ability within salinity of 20-25 g/L; MD5 and MD8 were significantly inhibited under C/N ratio of 6（P 0.05）, with the optimal C/N ratio of MD5（C/N = 8） lower than that of MD8. The above results revealed that MD5 and MD8 were two strains of nitrifying-aerobic denitrifying bacteria, which could be applied for bioremediation of aquaculture effluents.
出处
《应用与环境生物学报》
CAS
CSCD
北大核心
2017年第1期157-163,共7页
Chinese Journal of Applied and Environmental Biology
基金
国家科技支撑计划课题(2012BAC07B03)
南通市农业科学创新项目(HL 2014014)
江苏省三新工程项目(PJ2014-51)资助~~
