Modelling the biomineralisation processes which form calcite coccoliths

模拟形成方解石球石的生物矿化过程

• 批准号: 5314974
• 负责人: Professorin Dr. Annie Powell
• 金额: --
• 依托单位: Institut für Anorganische Chemie (aoc)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2001
• 资助国家: 德国
• 起止时间: 2000-12-31 至 2006-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5314974?language=en
• 关键词: Modelling; biomineralisation; processes; form; calcite

One of the most intriguing aspects of the process of biomineralisation is the means by which organisms are able to direct crystallisation to produce a desired crystal phase and crystal shape. In previous work we were able to shed light on both nucleation and crystal growth processes in iron hydroxide based systems. We wish to apply our approach to the calcium carbonate system and, in particular, to the question of how the marine coccolithophore, Emiliana Huxleyi, is able to produce single crystals of calcite in the shape of hammer-like plates which then are used to construct the coccosphere around the organism. Our approach will involve screening the effect that oxygen containing templates have on the calcium carbonate system. These templates are designed to serve as models for various parts of the polysaccharide template which is thought to be important in directing the structures of the coccoliths in the native system. Of particular relevance is our observation that performing crystallisations under hydrothermal conditions allows us to observe intermediate phases which still incorporate the template and therefore allow us suggest how the template affects growth in certain crystal directions in order to produce the final shape of the (bio)mineral. The systems will also be investigated under standard conditions both to compare the effects of applying hydrothermal conditions and also to shed light on the early, nucleating events which may be in operation.

生物矿化过程中最耐人寻味的方面之一是生物能够直接结晶以产生所需的晶相和晶体形状的方法。在以前的工作中，我们能够阐明氢氧化铁体系中的成核和晶体生长过程。我们希望将我们的方法应用于碳酸钙系统，特别是海洋球石生物体Emily iana huxleyi如何能够产生锤状板状的方解石单晶，然后这些单晶被用来构建有机体周围的球体。我们的方法将包括筛选含氧模板对碳酸钙体系的影响。这些模板被设计成用作多糖模板的不同部分的模型，该模板被认为在引导天然系统中的球藻的结构方面很重要。特别相关的是，我们观察到，在水热条件下进行结晶使我们能够观察到仍然包含模板的中间相，从而允许我们建议模板如何影响某些晶体方向的生长，以产生(生物)矿物的最终形状。还将在标准条件下对这些系统进行调查，以比较应用水热条件的效果，并阐明可能正在运行的早期成核事件。