多场耦合调控颗石藻矿化作用的微观机制及其环境指示意义

Coccolithophores is a class of single-celled autotrophic microalgaes which widely distributed in modern ocean. Fossil coccoliths which formed by a biomineralization process of coccolithophores have important significance in paleoceanography. For the complexity of biomineralization and environmental attributes, multi-field coupling conditions of living coccolithophores and in vitro biomimetic mineralization and samples of modern water, sediments and drill from marginal sea of China are selected for study. Mineralogy and biology characterizing techniques of mineral methods of synchrotron based chemical composition and fine structure spatial distribution, major and trace element composition, structure and spectroscopic, carbon and oxygen stable isotopes and analysis of physiological and biochemical assays are used in this project. According to typomorphic characteristics of fine mineral and response to environmental changes, and their relationships between each other, the environment coupled micro regulation mechanism of coccolithopores mineralization will be revealed and quantitative indicators of coccolithopores mineralization for response vertical variation of marine environment will be built for applying to forecasting future adaption mechanism and inversing Holocene paleoceanographic and paleoclimatic marine conditions of marginal sea of China. In this project, the in-depth study of coccolithophores mineralization will be help for understanding the scientific questions of biomineralization of environmental regulated mechanism and environmental response and provided guidance for the studying microbial mineralization in geochemical processes.

颗石藻是一类广泛分布于现代海洋的超微型浮游单细胞植物，经生物矿化作用形成的颗石粒在古海洋学研究中具有重要意义。针对颗石藻矿化作用及其环境属性的复杂性，选取多场耦合条件下的活体颗石藻矿化作用及体外仿生矿化作用和中国近海现代海洋及钻孔样品为研究对象。通过生物学与矿物学交叉，以同步辐射化学成分及精细结构的空间分布、显微形态、主微量元素成分、结构、谱学、碳氧稳定同位素等矿物学方法和生理生化表征技术，获取颗石藻矿化作用的精细矿物标型特征和响应环境变化的环境标型特征以及相互之间内在联系，揭示颗石藻矿化作用的微观环境耦合调控机制，建立利用颗石藻指示海洋环境变化的量化指标，应用于预测颗石藻应对中国近海未来海洋与气候变化的适应机制和反演中国近海全新世古海洋与古气候的研究。本项目的开展，能够深化对生物矿化作用的环境调控机制和环境响应规律等科学问题的认识，为阐明微生物矿化作用的地球化学过程提供科学指导。

颗石藻是一类广泛分布于现代海洋的超微型浮游单细胞植物，经生物矿化作用形成的颗石包含了丰富的环境矿物学信息，对地球环境的变化具有重要指示作用。针对颗石藻矿化作用及其环境属性的复杂性，本项目选取多场耦合条件（二氧化碳、温度、主微量元素等）下的活体颗石藻矿化作用、体外仿生和中国近海富颗石柱状样为研究对象，开展了颗石藻介导的锶钙协同矿化作用及其环境效应、颗石藻介导的铁元素生物地球化学循环、颗石藻的细胞结构及功能仿生、颗石藻生物矿化作用的体外仿生、海洋粘土矿物与颗石藻相互作用、中国南海西部富颗石柱状样 (MD05-2901)的矿物学特征和多场耦合条件下的颗石藻生物矿化作用等8项研究。通过颗石藻的精细矿物标型特征，探讨了颗石藻响应环境变化的环境标型特征以及相互之间内在联系。通过同步辐射化学成分及精细结构的空间分布、显微形态、主微量元素成分、结构、谱学等矿物学方法和生理生化表征技术，揭示了颗石藻矿化作用的环境耦合微观调控机制，为生物矿化作用的环境调控机制和环境响应规律等科学问题的认识，以及阐明微生物矿化作用的地球化学过程提供了科学证据。本项目的研究成果对利用颗石藻指示海洋环境变化、预测颗石藻应对海洋环境与气候变化的适应机制和反演古海洋与古气候的研究具有一定科学参考价值。