[Effect of light period length on the movement of exogenous phosphorus within simulative aqueous eco-systems]

Effect of light period length on the movement of exogenous phosphorus within aqueous eco-systems composed with water, Microcystis aeruginosa and sediments was studied by the method of phosphorus isotope tracer. Exogenous phosphorus was initially distributed rapidly in the systems in a mode of physical chemistry and then its movement was significantly influenced by the growth of M. aeruginosa. With the increasing of the light period length, the growth rate and cell density rose gradually and exogenous phosphorus level declined rapidly in the water. The light period length had nothing to do with the maximum of endocellular phosphorus per mg M. aeruginosa. After certain amounts of exogenous phosphorus were accumulated in M. aeruginosa, its growth didn't affect the amounts of endocellular phosphorus. When the light period length was long, the total amounts of exogenous phosphorus was high in M. aeruginosa. The exogenous phosphorus moved from water and cyanobacteria to sediment continuously until most of exogenous phosphorus transferred into sediment through the decline of M. aeruginosa.