Impacts of CO_2 enrichment on growth and photosynthesis in freshwater and marine diatoms

作     者：胡晗华 高坤山 

作者机构：State Key Laboratory of Freshwater Ecology and BiotechnologyInstitute of HydrobiologyChinese Academy of Sciences State Key Laboratory of Freshwater Ecology and Biotechnology.Institute of HydrobiologyChinese Academy of Sciences Marine Biology Institute Shantou University 

出 版 物：《Chinese Journal of Oceanology and Limnology》 (中国海洋湖沼学报（英文版）)

年 卷 期：2008年第26卷第4期

页      面：407-414页

核心收录：

学科分类：09[农学] 0903[农学-农业资源与环境] 

基　　金：Supported by the National Natural Science Foundation of China (No.90411018 30270036) and by the Chinese Academy of Sciences 

主　　题：carbon dioxide Chaetoceros muelleri elevated CO2 growth Nitzschia palea photosynthesis 

摘      要：The physiological responses of Nitzschia palea Kvtzing, a freshwater diatom, to elevated CO2 were investigated and compared with those of a marine diatom, Chaetoceros muelleri Lemmermann previously reported. Elevated CO2 concentration to 700 μl/L increased the dissolved inorganic carbon （D!C） and lowered the pH in the cultures of N. palea, thus enhancing the growth by 4%-20% during the whole growth period. High CO2-grown N. palea cells showed lower levels of dark respiration rates and higher Ik values. Light-saturated photosynthetic rates and photosynthetic efficiencies decreased in N. palea with the doubling CO2 concentration in airflow to the bottom of cultures, although the doubling CO2 concentration in airflow to the surface cultures had few effects on these two photosynthetic parameters. N. palea cells were found to be capable of using HCO5 in addition to gaseous CO2, and the CO2 enrichment decreased their affinity for HCO5 and CO2. Although doubled CO2 level would enhance the biomass of N. patea and C. muelleri to different extents, compared with the marine diatom, it had a significant effect on the specific growth rates of N. palea. In addition, the responses of photosynthetic parameters of IV. palea to doubled CO2 concentration were almost opposite to those of C. muelleri.