微藻无机氮利用过程中的稳定氮同位素分馏  

Stable Nitrogen Isotope Fractionation during the Utilization of Inorganic Nitrogen by Microalgae

作　　者：李海涛 吴沿友[2] LI Haitao;WU Yanyou(Guizhou Vocational College of Agriculture,Guiyang 551400,China;State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China)

机构地区：[1]贵州农业职业学院,贵阳551400 [2]中国科学院地球化学研究所环境地球化学国家重点实验室,贵阳550081

出　　处：《地球与环境》2019年第6期839-843,共5页Earth and Environment

基　　金：国家自然科学基金项目(40973060、U1612441-2)

摘　　要：选用两种δ15N差异显著的铵态氮和硝态氮,分别设置不同浓度的铵态氮和硝态氮来处理莱茵衣藻和蛋白核小球藻,通过分析微藻的稳定氮同位素组成变化,来研究微藻利用不同浓度、不同形态无机氮过程中的稳定氮同位素分馏特征。结果显示,在未添加无机氮的条件下,微藻利用有机氮时,生长缓慢,稳定氮同位素基本上不存在分馏;在添加低浓度无机氮(≤20 mmol/L)时,微藻的生长和稳定氮同位素分馏都随着无机氮浓度的增加而增加;而添加高浓度无机氮(>20 mmol/L)时,微藻的生长趋于稳定,铵态氮条件下的微藻稳定氮同位素分馏继续加大,而硝态氮条件下的微藻稳定氮同位素分馏反而减小,可能与此时微藻硝酸还原酶的活力减小有关。Chlamydomonas reinhardtii and Chlorella pyrenoidosa were treated under different concentrations of ammonium and nitrate with different δ15N.The characteristics of stable isotope fractionation were determined under different inorganic nitrogen treatments.The results showed that microalgae grew slowly and showed no stable nitrogen isotope fractionation when the organic nitrogen from the culture medium was the only available nitrogen source.In the case of low inorganic nitrogen concentration,the growth of microalgae and the stable nitrogen isotope fractionation increased when the inorganic nitrogen concentration was increased up to 2.0 mmol/L,in the case of high inorganic nitrogen concentration(>2.0 mmol/L),the growth of microalgae tended to be stable,the stable nitrogen isotope fractionation tended to increase during the utilization of ammonium,but decreased during the utilization of nitrate.These observations may be related to the decrease of nitrate reductase activity in microalgae.

关 键 词：莱茵衣藻 蛋白核小球藻 铵态氮 硝态氮 氮同位素组成 

分 类 号：P512[天文地球—地质学]