不同季节和N、P营养条件对蛋白核小球藻(Chlorella pyrenoidosa)生长的影响

Effects of Seasons and N and P Nutrition on the Growth of Chlorella pyrenoidosa

为研究不同季节条件以及N、P浓度下蛋白核小球藻(Chlorella pyrenoidosa)的生长特性,实验设置3个光照、温度组合水平(450μmol/m2.s,15℃;60μmol/m2.s,25℃;100μmol/m2.s,10℃)模拟春季、夏季和冬季,每一季节设置低(TN:0.2mg/L,TP:0.01mg/L)、中(TN:2mg/L,TP:0.1mg/L)、高(TN:6mg/L,TP:0.3mg/L)3个N、P初始浓度水平以培养蛋白核小球藻.实验结果表明:在春季和夏季条件下,N、P浓度越高,小球藻叶绿素a浓度越容易达到富营养化水平;在冬季条件下,仅中N、P浓度培养的小球藻叶绿素a浓度达到富营养化水平.②不同N、P浓度条件下的小球藻相对生长速率受季节的影响程度不同,即N、P浓度和季节条件对小球藻的生长存在交互作用.③在实验室模拟的乌江水体环境下(静止培养),蛋白核小球藻在春、夏季极易发生"水华".

In quiescent culture, the growth of Chlorella pyrenoidosa was investigated at different nutrient （nitrogen and phosphorus） levels and in different seasons. Three combinations of light and temperature （450 μmol/m^2·s^-1,15 ℃;60 μmol/m^2·s^-1, 25℃ and 100 μmol/m^2·s^-1, 10 ℃） were made to simulate the conditions of spring, summer and winter, and in each season three initial NP concentrations were designed, TN 0.2 mg · L^-1 ＋TP 0.01 mg· L^-1 , TN2mg· L^-1 ＋TP 0. 1 mg· L^-1 and TN 6 mg · L^-1 ＋TP 0.3 mg · L^-1. The growth rate of chlorophyll a content of C. pyrenoidosa was linearly related to nutrient concentration in spring and summer, i. e. the higher the nutrient concentration was, the faster it grew. But in winter, C. pyrenoidosa reached eutrophication level only at middle nutrient level （TN 2 mg · L^-1＋TP 0.1 mg· L^-1 ）. The influence of season on the relative growth rate of C. pyrenoidosa varied with the nutrient concentration level, which means that nutrient concentration and season were interacted to in their influence on the growth of C. pyrenoidosa. Under the experimental conditions which stimulated the water conditions of the Wujiang River, C. pyrenoidosa was most likely to research eutrophication in spring and summer.