温度、pH和氮、磷含量对铜绿微囊藻(Microcystis aeruginosa)生长的影响

EFFECTS OF TEMPERATURE,pH,NITROGEN AND PHOSPHORUS ON GROWTH OF MICROCYSTIS AERUGINOSA

以南太湖水华蓝藻铜绿微囊藻为材料,研究了温度、pH和氮、磷浓度对铜绿微囊藻生长的影响,为阐述微囊藻水华形成的机制提供科学依据。研究结果表明,铜绿微囊藻对温度的适应范围较广,15—40℃温度范围内铜绿微囊藻均可生长,25—30℃为铜绿微囊藻的最适生长温度,当温度达到45℃时,铜绿微囊藻停止生长并逐渐死亡。在pH6.5—9.5范围内,铜绿微囊藻均有较高的生长量,最适pH为8.0—9.0,pH值高于9.0时,铜绿微囊藻的最终生长量略有下降。BG-11培养基中添加高浓度的氮(1g/LNH4Cl)后,铜绿微囊藻的生长被显著抑制(P<0.01),但同时添加不同浓度的磷(0.36—10mg/LKH2PO4)后,显著地提高了铜绿微囊藻的生长(P<0.01),不同磷浓度处理之间无极显著差异,氮磷平衡是影响铜绿微囊藻生长的重要因素。

Harmful algal blooms in Taihu Lake have been increasing with the eutrophication in recent years. Micro- cystins produced by bloom-forming cyanobateria are harmful to environment, animals and human beings. In this study, the effects of temperature, pH, and nitrogen and phosphorus on the growth of Microcystis aeruginosa from south Taihu Lake were investigated for understanding the development of the Microcystis bloom with UV-visible spectrophotometer at 665nm wavelength. M. aeruginosa could survive and grow in a wide range of temperature 15—40℃ with the optimum 25—30℃; beyond 45℃ it stopped growing and died gradually. pH at 6.5—9.5 favoured the growth and the optimum was at 8.0—9.0. Adding high-concentration nitrogen （1g/L NH4Cl） into the BG-11 medium inhibited the growth significantly （P0.01）. However, adding phosphorus （0.36—10mg/L KH2PO4） at the same time significantly increased the growth （P0.01）. No significant differences were observed among different concentrations of phosphorus （P0.01）. The results indicate that the co-action of nitrogen and phosphorus is an important factor on the growth of M. aeruginosa.