不同氮源和环境因子对花津滩芽孢杆菌 SLWX2脱氮性能的影响

Effects of Different Nitrogen Sources and Environmental Factors on the Nitrogen Removal Performance of Bacillus hwajinpoensis SLWX2

中文关键词: 花津滩芽孢杆菌  生物脱氮  唯一氮源  环境因素  去除率

英文关键词: Bacillus hwajinpoensis  Bio-removal of nitrogen  Sole nitrogen source  Environmental factors  Removal rate

中文摘要:

      花津滩芽孢杆菌(Bacillus hwajinpoensis) SLWX2是1株从海水养殖环境分离的可高效去除水体中氨氮(NH4+-N)、亚硝酸氮(NO2–-N)和硝酸氮(NO3–-N)的菌株。本实验在添加葡萄糖条件下，研究NH4+-N、NO2–-N和NO3–-N作为唯一氮源和环境因子(温度、pH、C/N和盐度)对该菌株生长和脱氮性能的影响。结果显示，菌株对这3种形态氮的去除与其生长保持一致，主要发生在对数生长期；当NH4+-N作为唯一氮源时，生长和脱氮均没有延迟期，NH4+-N在去除过程中，没有NO2–-N和NO3–-N的积累；当NO2–-N作为唯一氮源时，生长和脱氮均有较长延迟期，在NO2–-N消除过程中，没有NH4+-N和NO3–-N的积累；当NO3–-N作为唯一氮源时，生长和脱氮也有较长延迟期，在NO3–-N消除过程中，基本检测不到NH4+-N，NO2–-N呈先上升后下降趋势。环境因子影响研究表明，环境因子对该菌株的生长和脱氮性能影响基本一致，在pH为6~8.5、温度为28~40℃、C/N为5~25、NaCl为0~30 g/L条件下，菌株展现了良好的生长特性和脱氮性能。其中，最佳条件中，温度为30℃，C/N为25，pH为8.0，盐度为25。该菌株可高效去除NH4+-N、NO2–-N和NO3–-N，对环境条件适应范围较广，在工业和养殖废水脱氮中具有较大的应用潜力。

英文摘要:

      Bacillus hwajinpoensis SLWX2 is a bacterium strain isolated from maricultural environments that can effectively remove NH4+-N, NO2–-N, and NO3–-N from water. In this study, the effects of different nitrogen sources (NH4+-N, NO2–-N, and NO3–-N) and environmental factors (temperature, pH, C/N, and salinity) on growth and nitrogen removal were studied. The results showed that the growth of Bacillus hwajinpoensis SLWX2 was consistent with the removal of the three forms of inorganic nitrogen, which occurred mainly in the logarithmic growth phase. There was no delay in growth of the bacterial cells and NH4+-N removal, and no NO2–-N nor NO3–-N was produced when NH4+-N was used as the sole nitrogen source. Further, there was no accumulation of NH4+-N and NO3–-N when NO2–-N was used as the sole nitrogen source, but there was a long delay in growth and NO2–-N removal. NH4+-N was not detected, but NO2–-N first accumulated and then decreased when NO3–-N was used as the sole nitrogen source. The experimental results showed that the effects of the environmental factors on the growth of SLWX2 correlated with its ammonium removal function. The strain showed good growth and ammonium removal performance under the conditions of weak acids, neutral, and weak bases (pH 6~8.5), temperature 28~40℃, C/N 5~25, and NaCl 0~30 g/L. The optimal conditions for SLWX2 were temperature of 30℃, C/N 25, pH 8.0, and salinity 25. The strain SLWX2 showed high efficiency in removing NH4+-N, NO2–-N, and NO3–-N in water, and it has a wide adaptation range to environmental conditions, which suggests its huge potential in bio-removal of nitrogen in waste water from industries and aquaculture.