脱氮副球菌的好氧反硝化特性及对养殖水体中氮素的控制

以一株脱氮副球菌（Paracoccus denitrificans）为试验菌株,研究了其在好氧环境下的最适生长条件以及在不同溶氧条件下对NO2--N、NO3--N的转化去除情况。结果表明,脱氮副球菌好氧下的最适生长温度为30℃,最适生长pH值为7.0。在溶解氧比较充足的情况下（6.6～7.3mg.L-1）,脱氮副球菌对NO2--N、NO3--N的去除以同化吸收为主,少部分是经由反硝化作用去除,最大去除率可达100%和97.58%。随着溶氧的降低,脱氮副球菌的反硝化能力增强,NO2--N、NO3--N通过反硝化作用去除的比例增加。将活菌数≥109个.mL-1的脱氮副球菌按1.0、2.5mg.L-1的浓度加入养殖水体,在10d内可使养殖水体中的NH4＋-N下降41.89%～49.23%,NO2--N下降33.33%～42.86%,NO3--N下降48.28%～67.74%,对养殖水体中的氮素污染具有较好的控制效果。研究显示,脱氮副球菌的好氧反硝化作用可以为养殖水体有氧条件下的脱氮提供一条新的思路。

The Aerobic Denitrification Characteristics of Paracoccus Denitrificans and Its Nitrogen Control for Aquaculture Water

This paper focused on the aerobic denitrification characteristics of Paracoccus denitrificans and its nitrogen control for aquaculture water. In the experiment, Paracoccus denitrificans was used to determine its optimum growth conditions under aerobic condition and removal effect of NO2-N, NO3-N under different dissolved oxygen conditions. The results showed that, under aerobic condition, the optimum growth temperature was 30 ~C, the optimum pH value was 7.0. Under high dissolved oxygen condition （6.6~7.3 mg＂ L-1 ）, the maximum removal rate of NO2-N and NO;-N, removed via assimilation, but minor removed via denitrification, reached to 100% and 97.58%, respectively. With the decrease of dissolved oxygen, the denitrification capacity of Paracoccus denitrificans was enhanced, and the removal proportion via denitrifi- cation increased. Paracoccus denitrificans （viable counts i〉 109.mL-1） was used to control the nitrogen pollution of aquaculture water, when the concentration of Paracoccus denitrificans in aquaculture water reached to 1.0 mg＂ Lq and 2.5 mg-L-1, the NH~-N of aquaculture water decreased by 41.89%~49.23%, NOi-N decreased by 33.33%~42.86%, NO~-N decreased by 48.28%~67.74% within 10 days. The results in- dicated that Paracoccus denitrificans could effectively control nitrogen pollution of aquaculture water. The details of the aerobic denitrifica- tion ofParacoccus denitrificans provided a new idea for nitrogen removal of aquaculture water.