The uronic acid content of coccolith-associated polysaccharides provides insight into coccolithogenesis and past climate.
The uronic acid content of coccolith-associated polysaccharides provides insight into coccolithogenesis and past climate.
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DOI：
10.1038/ncomms13144
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发表时间：
2016-10-26
影响因子：
16.6
通讯作者：
Rickaby RE
中科院分区：
文献类型：
--
作者：
Lee RB;Mavridou DA;Papadakos G;McClelland HL;Rickaby RE
单细胞植物共生藻类（颗石藻）是地球上最多产的碳酸钙生产者之一，每年生产1026颗石。颗石藻在其结石形成过程中，主要利用与颗石相关的多糖（CAPs）来调节晶体的成核和生长。这些大分子通过糖醛酸残基的带电羧基与细胞内钙化区室（颗石囊泡）相互作用。在这里，我们报告的隔离CAPs从现代颗石藻和他们的史前前辈，我们证明了他们的糖醛酸含量（UAC）提供了一个物种特异性的签名。我们还表明，有一个UAC的CAP和内部饱和状态的球石囊泡，地质丰富的物种，是密不可分的碳供应之间的相关性。这些研究结果表明，UAC的CAPs报告的适应球石形成的环境变化，并可用于估计过去的CO2浓度。颗石相关多糖（CAPs）是海洋藻类生物矿化的核心。在这里，Lee等人表明CAPs可以从现存和化石样品中分离出来，并且它们的糖醛酸含量可以用作古气候的代用指标。
Unicellular phytoplanktonic algae (coccolithophores) are among the most prolific producers of calcium carbonate on the planet, with a production of ∼1026 coccoliths per year. During their lith formation, coccolithophores mainly employ coccolith-associated polysaccharides (CAPs) for the regulation of crystal nucleation and growth. These macromolecules interact with the intracellular calcifying compartment (coccolith vesicle) through the charged carboxyl groups of their uronic acid residues. Here we report the isolation of CAPs from modern day coccolithophores and their prehistoric predecessors and we demonstrate that their uronic acid content (UAC) offers a species-specific signature. We also show that there is a correlation between the UAC of CAPs and the internal saturation state of the coccolith vesicle that, for most geologically abundant species, is inextricably linked to carbon availability. These findings suggest that the UAC of CAPs reports on the adaptation of coccolithogenesis to environmental changes and can be used for the estimation of past CO2 concentrations. Coccolith-associated polysaccharides (CAPs) are central for the biomineralization of marine algae. Here, Lee et al. show that CAPs can be isolated from extant and fossil samples and that their uronic acid content can be used as a palaeoclimate proxy.