[Dynamic studies on the effect of nutrients on the growth of Microcystis aeruginosa].
The effects of nitrogen and phosphorus on the growth of Microcystis aeruginosa were investigated by using the Monod equation. The semi-saturation constants of Microcystis aeruginosa to TP (KsP) and TN (KsN) were calculated. The results show that KsN is higher than KsP. This indicates that the effect of TP on the growth of Microcystis aeruginos is further more significant than that of TN. Further analysis finds that extant quantity (X) and special growth rate (micro) of Microcystis aeruginosa increase with TP or TN, and there exists a point of inflection. When the concentrations of TP and TN ranged from 0.005mg/L to 0.2mg/L and from 0.01mg/L to 2mg/L respectively with TP or TN as the single limiting substrate, the growth rate of Microcystis aeruginosa increased rapidly. Because Microcystis aeruginosa exhibits different affinity with TP and TN (according to the semi-saturation constants), the effect of N/P ratio on the growth of Microcystis aeruginosa does not demonstrate at a constant value. No constant ratio can be used to determine the limiting nutrient elements on the growth of Microcystis aeruginosa in any aquatic environment. The effect of N/P ratio on the growth of Microcystis aeruginosa depends on both the N and P concentrations and the N/P ratio.
Zheng
Shuo-fang
SF
Limnology Base of Chinese Research Academy of Environmental Sciences, Beijing, China.
Yang
Su-wen
SW
Jin
Xiang-can
XC
D005068:Eutrophication; D005618:Fresh Water / Q000032:analysis; D046931:Microcystis / Q000166:cytology / Q000187:drug effects*; D009584:Nitrogen / Q000494:pharmacology; D010758:Phosphorus / Q000494:pharmacology*; D010839:Phytoplankton / Q000166:cytology; D014873:Water Pollutants / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
D014873:Water Pollutants; D010758:Phosphorus; D009584:Nitrogen