空心菜对不同形态氮吸收动力学特性研究

对空心菜不同形态氮素吸收动力学特性进行了研究，发现其吸附曲线均符合Michaelis-Menten酶动力学方程，采用LB转换式处理数据对其动力学参数进行计算，得出以下结论:①空心菜对铵态氮的亲和力大于对硝态氮的亲和力（K_m铵态氮<K_m硝态氮），说明空心菜有优先吸收铵态氮的趋势，表明在实际净化水质过程中，若有足够的停留时间，空心菜对铵态氮的净化程度更高一些；②空心菜对铵态氮的最大吸收速率V_max为0.001 85 mmol/（g·FW·h），对硝态氮最大吸收速率V_max 为0.000 279 mmol/（g·FW·h），V_max铵态氮>V_max硝态氮，表明空心菜对铵态氮的净化速率要大于对硝态氮的净化速率；③当溶液中存在铵态氮时，空心菜对硝态氮的亲和力增加了2.5%，而最大吸收速率则减少34%，总的吸收能力降低，表明溶液中铵态氮的存在不影响空心菜根细胞膜上载体与硝态氮之间的亲和性，但影响载体对硝态氮的运转速度。

Uptake Kinetic Characteristics of Different Ammonium and Nitrate by Ipomoea aquatica Forsk

The uptake Kinetic characteristics of different ammonium and nitrate by Iponoea aquatica Forsk was researched. The results showed that ①The Km value of ammonium uptake was less than that of nitrate uptake by Ipomoea aquatica Forsk (K_{m ammoniumm nitrate), Which indicated that the Ipomoea aquatica Forsk preferential uptake and clean up ammonium and reflected the cleaning degree would be higher in the enough retention time. ②The maximum rate of ammonium uptake by Ipomoea aquatica Forsk was larger than that of nitrate uptake and the maximum rate of ammonium was 0.001 85 mmol/ (g·FW·h) and the maximum rate of nitrate was 0.000 279 mmol/ (g·FW·h), which indicated that the purification rate of the ammonium was bigger than nitrate. ③The Km of nitrate uptake increased 2.5% and the maximum rate of nitrate decreases 34% with the existence of NH4⁺ and the uptake ability decreased, which indicated that the Km between the carrier of cell membrane and the nitrate of Ipomoea aquatica Forsk would not been affected, but the operation speed would been influenced with the existence of NH4⁺.}