几种浮游单细胞藻类磷代谢的初步研究

用３２ＰＯ４３－同位素稀释法研究了单种一次培养的几种浮游单细胞藻类的磷代谢．小球藻（Ｃｈｌｏｒｅｌｌａｓｐ．）和一种绿藻对ＰＯ４３－的最大吸收速率（Ｖｍａｘ）与细胞磷含量成负相关，半饱和速率常数（Ｋｓ）与藻类的种类相关．光照与黑暗对中华盒形藻（ＢｉｄｄｕｌｐｈｉａｓｉｎｅｎｓｉｓＧｒｅｖｉｌｅ）和金藻（Ｄｉｃｒａｔｅｒｉａｓｐ）ＰＯ４３－的吸收和再生代谢无明显影响，其昼夜变化是藻类细胞新陈代谢的反映；处于细胞周期Ｇ１期与Ｓ期的藻类有较高的磷吸收和再生代谢速率，而Ｇ２期与Ｍ期的磷代谢速率较低．藻类磷代谢的动力学及其昼夜变化是围绕着对营养盐磷最大程度地利用和维持藻类持续生长的机制展开的．

Preliminary Studeis on Phosphorus Metabolism of Some Planktonic Unicell Algae

phosphorus metabolism of some planktonic unicell algae was studied by 32PO43- in isotope-dilution method in the laboratory by monospecific batch culture. PO43- uptake kinetics of Chorella sp. and another chlorophyta specie follows Michaelis-Menten equation, Vmax was negatively correlated with algee cellular phosphorus. Ks was related to the spedes of algae. PO43- uptake and regeneration metabolisms of Biddulphia sinensis and Dicrateho sp. were not obviously influenced by light and dark conditions,and their diel variations were a reflection of cellular metabolic status. Phosphate uptake and regeneration metabolic rates were higher during gap1 and synthetic phases of algae cell cycle, but were lower during gap2 and mitotic phases,There was a mechanism on phosphate uptake kinetics and diel variations of algae phosphorus metabolism, which maximizes the utilization of phosphorus and supports continuous growth of algae.