Insights into the response of coral biomineralisation to environmental change from aragonite precipitations in vitro
Insights into the response of coral biomineralisation to environmental change from aragonite precipitations in vitro
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DOI：
10.1016/j.gca.2023.10.032
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发表时间：
2023-10
影响因子：
5
通讯作者：
Cristina Castillo Alvarez;K. Penkman;Roland Kröger;Adria Finch;M. Clog;Alex Brasier;John Still;N. Allison
中科院分区：
文献类型：
--
作者：
Cristina Castillo Alvarez;K. Penkman;Roland Kröger;Adria Finch;M. Clog;Alex Brasier;John Still;N. Allison
海洋生物 CaCO3 矿物的沉淀发生在专门地点，通常具有较高的 pH 值和溶解的无机碳，并且存在控制碳酸钙结构的成核、生长和形态的生物分子。在这里，我们在当前和未来大气二氧化碳情景下推断热带珊瑚钙化介质中发生的条件下探索文石沉淀。我们在实验之间改变 pH、ΩAr 和 pCO2，以探索 HCO3− 和 CO32− 如何影响沉淀速率，并确定珊瑚骨架中三种最常见的氨基酸（天冬氨酸、谷氨酸和甘氨酸）对沉淀速率和文石形态的影响。我们发现流体 ΩAror [CO32−] 是 25 °C 下沉淀速率的主要控制因素，HCO3− 或 pH 没有显着贡献。所有氨基酸在 0.2–5 mM 时都会抑制文石沉淀，抑制程度与 ΩArand 呈负相关，就天冬氨酸而言，还与海水温度呈负相关。在测试的氨基酸中，天冬氨酸对沉淀的抑制作用最强（并产生文石形态的变化），而甘氨酸对沉淀的抑制作用最小。先前的工作表明，海洋酸化增加了珊瑚骨骼的氨基酸含量，并可能减少了钙化介质ΩAr，这两者都可以抑制文石沉淀。这项研究和之前的工作表明，文石沉淀率与 10 至 30°C 的温度呈指数关系，并且海水温度的小幅人为升高可能会抵消由于海洋酸化下骨骼天冬氨酸增加和钙化介质 Ω 减少而预计发生的沉淀率抑制。
Precipitation of marine biogenic CaCO3minerals occurs at specialist sites, typically with elevated pH and dissolved inorganic carbon, and in the presence of biomolecules which control the nucleation, growth, and morphology of the calcium carbonate structure. Here we explore aragonite precipitationin vitrounder conditions inferred to occur in tropical coral calcification media under present and future atmospheric CO2scenarios. We vary pH, ΩArand pCO2between experiments to explore how both HCO3−and CO32−influence precipitation rate and we identify the effects of the three most common amino acids in coral skeletons (aspartic acid, glutamic acid and glycine) on precipitation rate and aragonite morphology. We find that fluid ΩAror [CO32−] is the main control on precipitation rate at 25 °C, with no significant contribution from HCO3−or pH. All amino acids inhibit aragonite precipitation at 0.2–5 mM and the degree of inhibition is inversely correlated with ΩArand, in the case of aspartic acid, also inversely correlated with seawater temperature. Aspartic acid inhibits precipitation the most, of the tested amino acids (and generates changes in aragonite morphology) and glycine inhibits precipitation the least. Previous work shows that ocean acidification increases the amino acid content of coral skeletons and probably reduces calcification media ΩAr, both of which can inhibit aragonite precipitation. This study and previous work shows aragonite precipitation rate is exponentially related to temperature from 10 to 30 °C and small anthropogenic increases in seawater temperature will likely offset the inhibition in precipitation rate predicted to occur due to increased skeletal aspartic acid and reduced calcification media ΩArunder ocean acidification.