氮、磷、硅对条纹小环藻生长和叶绿素a含量的影响

采用单因子实验方法研究氮、磷和硅营养盐对条纹小环藻(Cyclotella striata)生长和叶绿素a含量的影响。结果表明:在不同磷和硅营养盐浓度下,条纹小环藻比生长率μ变化显著(P<0.05),其中,硝酸盐为0.60~0.85 d-1,硅酸盐为0.49~0.61 d-1,磷酸盐为0.46~0.51 d-1。总体而言,在一定的营养盐浓度范围内,条纹小环藻的最大藻细胞密度Nmax随着氮、磷和硅营养盐浓度的增加而增大;条纹小环藻叶绿素a(Chl a)含量亦随着氮、硅浓度的增加,与Nmax增加趋势一致,但随着磷浓度的增加Chl a先增加后减小,与Nmax不一致。条纹小环藻的主要限制营养元素是氮和硅,而磷可能不会成为其短期培养的限制因子。

Effects of Nitrate, Phosphate and Silicate on Growth and Chlorophyll-a Content of Cyclotella striata

The effects of nitrate,phosphate,and silicate on the growth and chlorophyll-a content of Cyclotella striata were studied by single factor experiments.The specific growth rate(μ) of C.striata varied widest from 0.60 to 0.85 d-1 under different nitrate concentration mediums,followed by 0.49-0.61 d-1 under different silicate concentrations and 0.46-0.51 d-1 under different phosphate concentrations.Generally,the maximum cell densities(Nmax) of C.striata increased with the increasing concentrations of different nitrate,phosphate and silicate.Chlorophyll-a contents of C.striata increased as the same trend as Nmax when growing under different nitrate and silicate concentrations.However,reversed trend for chlorophyll-a contents occurred when the algae was cultured under different phosphate concentrations,which might be results of the nitrate limitation when C.striata growing under high phosphate concentrations,as nitrogen was component element of chlorophyll-a composition.This study demonstrated that C.striata was a species more easily subjected to growth-limitation of nitrogen and silicon but phosphorous under couples days culturing.