亚硝态氮对铜绿微囊藻和四尾栅藻生长的影响

The effect of the nitrite nitrogen on the growth of Microcystis aeruginosa and Scenedesmus quadricauda

采用室内培养法,将铜绿微囊藻和四尾栅藻分别置于5种含不同质量浓度亚硝态氮（NO2^--N）（0.5 mg/L、1.0 mg/L、2.0 mg/L、4.0mg/L和8.0 mg/L）的培养液中,培养10 d,测定不同质量浓度NO2^--N对铜绿微囊藻和四尾栅藻生长的影响。结果表明,0.5-8.0 mg/L的NO2^--N可激活铜绿微囊藻的亚硝酸氧化酶和亚硝酸还原酶,进而促进铜绿微囊藻的生长。四尾栅藻因仅具有亚硝酸还原酶,因此只能利用0.5-2.0 mg/L的NO2^--N,其利用能力远没有铜绿微囊藻强。培养8 d后,铜绿微囊藻培养液中NH4^＋-N和NO2^--N的质量浓度明显升高,而NO3^--N质量浓度的变化不大;四尾栅藻培养液中NH4^＋-N、NO2^--N和NO3^--N质量浓度的变化不大。研究表明,低于8.0 mg/L的NO2^--N可促进铜绿微囊藻的生长,高于2.0 mg/L的NO2^--N抑制四尾栅藻的生长。

The present paper is concerned about our experimental results of the effect of the nitrite nitrogen on the growth of Microcystis aeruginosa Kütz and Scenedesmus quadricauda Breb. As can be seen, in our research experiments, Microcystis aeruginosa and Scenedesmus quadrlcauda were let to be exposed to the environment at five different mass concentrations of the nitrite nitrogen （ that is, 0.5 mg/L, 1.0 mg/L, 2.0 mg/L, 4.0 mg/L and 8.0 mg/L） to study the effect of the different mass concentrations of the nitrite nitrogen on the growth of Microcystis aeruginosa and Scenedesmus qtmdricauda. The results of our experiments have shown that the nitrite reductase and the nitrite oxidase of Microcystis aeruginosa could be activated in the environmental mass concentration of the nitrite nitrogen （0.5 - 8.0 mg/L） so that it can help the nitrite nitrogen lower than 8.0 mg/L to grow. However, Scenedesmus quadricauda only had the nitrite reductase and was able to use the nitrite nitrogen of 0.5 - 2.0 mg/L for its activation, so that the nitrite nitrogen could be used far less than that of Microcystis aeruginos. Thus, it can be seen that, except that the nitrite nitrogen and anunonia nitrogen in the culture medium of Microcystis aeruginosa may turn to be noticeably higher after the eighth day, no remarkable change would happen to the nitrate nitrogen, neither the ammonia nitrogen, nitrite nitrogen and nitrate nitrogen in the culture medium of Scenedesmus quadricauda.