Calcification response of Pleurochrysis carterae to iron concentrations in batch incubations： implication for the marine biogeochemical cycle  

作　　者：Xiang ZOU Shiyong SUN Sen LIN Kexuan SHEN Faqin DONG Daoyong TAN Xiaoqin NIE Mingxue LIU Jie WEI 

机构地区：[1]School of Environment and Resources, Key Laboratory of Solid Waste Treatment and Resource Recycle, Southwest University of Science and Technology, Mianyang 621010, China [2]State Key Laboratory of Marine Geology, TonNi University, Shanghai 200092, China [3]Low-cost Wastewater Treatment Technology International Sci-Tech Cooperation Base of Sichuan Province, Mianyang 621010, China

出　　处：《Frontiers of Structural and Civil Engineering》2017年第4期682-688,共7页结构与土木工程前沿（英文版）

摘　　要：Calcified coccolithophores, a diverse and widely distributed group of marine microalgae, produce biogenic calcite in the form ofcoccoliths located on the cell surface. Using batch incubations of the coccolithophorid Pleurochrysis carterae, we investigated the responses of this calcification process to iron concentrations by changing the iron supply in the initial culture media from a normal concentration to 1 ppm （parts per million）, 5 ppm, and 10 ppm. Time-dependent measurements of cell population, production of inorganic carbon （coccoliths）, and organic carbon （organic cellular components） showed that elevated iron supply in the growth medium of P. carterae stimulates carbon sequestration by increasing growth along enhanced photosynthetic activity and calcification. In addition, the acquired time-dependent UV-Vis and FT-IR spectra revealed that iron fertilization- enhanced coccolith calcification is accompanied by a crystalline phase transition from calcite to aragonite or amorphous phase. Our results suggest that iron concentration has a significant influence on the marine carbon cycle of coccolithophores.Calcified coccolithophores, a diverse and widely distributed group of marine microalgae, produce biogenic calcite in the form ofcoccoliths located on the cell surface. Using batch incubations of the coccolithophorid Pleurochrysis carterae, we investigated the responses of this calcification process to iron concentrations by changing the iron supply in the initial culture media from a normal concentration to 1 ppm （parts per million）, 5 ppm, and 10 ppm. Time-dependent measurements of cell population, production of inorganic carbon （coccoliths）, and organic carbon （organic cellular components） showed that elevated iron supply in the growth medium of P. carterae stimulates carbon sequestration by increasing growth along enhanced photosynthetic activity and calcification. In addition, the acquired time-dependent UV-Vis and FT-IR spectra revealed that iron fertilization- enhanced coccolith calcification is accompanied by a crystalline phase transition from calcite to aragonite or amorphous phase. Our results suggest that iron concentration has a significant influence on the marine carbon cycle of coccolithophores.

关 键 词：CALCIFICATION COCCOLITHOPHORES iron fertiliza- tion Pleurochrysis carterae 

分 类 号：TU0[建筑科学]