Calcification by amorphous pathways: Establishing effects of acidification and interplays with Mg and biomolecule chemistry

拟议的工作将侧重于了解海洋生物的钙化作用，并将挑战长期以来认为降水是通过经典结晶过程发生的观点。以往许多研究的解释都是基于这一概念。现在看来，大多数碳酸盐生物是通过非经典的生长过程形成骨架的，这种生长过程涉及一种非晶相，随着时间的推移，这种非晶相会转变为介晶的复合体。如果这是真的，那么目前通过分析最近形成或保存在海洋沉积物中的方解石骨架来推断环境影响和解释古记录的方法将需要修改，因为非经典过程的骨架形成依赖于一套不同的化学和环境条件。这项拟议的研究将建立在最近的发现基础上，这些发现表明酸化、镁浓度、生物分子化学和其他因素都会影响这一成矿途径。该项目将利用实验室研究和创新的分析方法，调查基于这一新范式的若干假设。动力学和热力学测量和建模将与化学和结构研究相结合，以建立生物矿化途径的完整物理图景。这项研究的更广泛的科学影响超出了化学海洋学领域，如果拟议的假设得到证实，将产生重大影响。该项目有重要的教育方面，包括研究生和本科生参与研究，并通过NSF资助的地球到生活系列发展K-12教育。

The proposed work will focus on understanding calcification by marine organisms and will challenge the long-standing view that precipitation occurs via classical crystallization processes. The interpretation of many past studies is based on this notion. It now appears that most carbonate-producing organisms form skeletons by non-classical growth processes which involve an amorphous phase that transforms to a composite of mesocrystals over time. If this is true then the current approaches to inferring environmental effects, and interpreting paleo records, from analysis of calcite skeletons, either recently formed or preserved in marine sediments, will need to be revised as skeleton formation by non-classical processes relies on a different set of chemical and environmental conditions. The proposed research will build on recent findings which suggest that acidification, magnesium concentration, biomolecule chemistry and other factors all influence this pathway to mineralization. The project will investigate a number of hypotheses based on this new paradigm using laboratory studies and innovative analytical approaches. Kinetic and thermodynamic measurements and modeling will be coupled with chemical and structural investigations to establish a complete physical picture of the biomineralization pathway. The scientific broader impacts of the research go beyond the field of Chemical Oceanography and will have substantial impact if the proposed hypotheses are confirmed. The project has significant educational aspects, with the inclusion of both graduates and undergraduates in the research, and K-12 education development through the NSF-funded Earth to Life series.