不同初始氮浓度对小球藻生长及氮吸收的影响  

Effects of Different Initial Nitrogen Concentrations on Growth and Nitrogen Absorption of Chlorella vulgaris

作　　者：杨坤[1] 李静[1,2] 卢文轩[1] 

机构地区：[1]安徽省农业科学院水产研究所,安徽合肥230031 [2]中科院南京地理与湖泊研究所,江苏南京210008

出　　处：《环境科学与技术》2014年第12期40-46,共7页Environmental Science & Technology

基　　金：安徽省农业科学院院长青年创新基金项目(13B0530)

摘　　要：将小球藻(Chlorella vulgaris)接入不同初始NO3--N浓度的培养基中进行培养,通过分析测定藻密度、细胞内氮、叶绿素-a和硝酸还原酶活性(NRA)等参数,探讨不同初始氮浓度对小球藻生长代谢的影响。结果显示:添加氮源可以明显促进小球藻的生长,且随着氮源浓度的提高促生长作用增强,但高浓度的氮在生长后期抑制了藻的生长。Monod方程揭示了藻的生长与水中氮浓度之间的关系,9.2 mg/L组的最大比生长率(μmax)在3个处理组中最大,然后依次是27.7 mg/L和4.6 mg/L组。半饱和常数(Ks)呈现4.6 mg/L>27.7 mg/L>9.2 mg/L组的趋势。小球藻细胞内氮与叶绿素-a的增长曲线基本吻合,细胞内份额氮与叶绿素-a的增长不同步。小球藻生长过程中NRA呈现先升高之后逐渐降低的趋势,9.2 mg/L和27.7 mg/L组NRA相近,表明NRA可能存在一定阈值。In this experiment,Chlorella vulgaris was cultured in medium containing different initial NO3--N concentrations.The function parameters were measured including cell density,concentrations of N-in-cells and chlorophyll-α,as well as activity of nitrate reductase,in order to explore the growth tendency and mechanism of nitrogen absorption of C. vulgaris.Results showed that cell density was increased with the increase of initial nitrogen concentrations,but high concentration of nitrogen restrained its growth at later stage. Monod equation revealed the relationship between C. vulgaris growth and nitrogen concentrations. The maximum special growth rate（μmax）was in order of 9.2 mg/L27.7 mg/L4.6 mg/L group,and the semisaturation constant（Ks）was in order of 4.6 mg/L27.7 mg/L9.2 mg/L group. The growth curves of N-in-cells were almost identical with that of chl-a,and the cells share of nitrogen peaked earlier than chl-a. Nitrate reductase activity（NRA）increased at first and then decreased. NRA was similar at the level of 9.2 mg/L and 27.7 mg/L,which suggested that NRA of C. vulgaris had a certain threshold.

关 键 词：小球藻 氮吸收 MONOD方程 细胞内氮 硝酸还原酶活性 

分 类 号：X172[环境科学与工程—环境科学]