Abstract Branched glycerol dialkyl glycerol tetraethers (brGDGTs) have proven useful for paleoclimate reconstructions. Nevertheless, the mechanism by which these biomarkers respond to the environment and the identity of the source organisms, remain poorly understood. These gaps in knowledge have prevented the study of brGDGTs in culture, thereby limiting the use of these molecules as a tool for paleoclimate reconstruction. In this work we used controlled microcosms to study the effect of temperature and pH on brGDGTs in lake water. Our results show that temperature has a strong influence on the production of brGDGTs, with a sensitivity that is similar to empirical observations. In contrast, the pH experiments yielded inconclusive results, either due to a limited response, or to the experimental set up. This study demonstrates that the brGDGT response to temperature can be replicated under controlled conditions, establishing that microcosms are a viable strategy to better understand the proxy response mechanism.

中文翻译：

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受控湖泊微观世界显示出 brGDGT 对环境扰动的响应

摘要支链甘油二烷基甘油四醚 (brGDGTs) 已被证明可用于古气候重建。然而，这些生物标志物对环境和来源生物的身份做出反应的机制仍然知之甚少。这些知识空白阻碍了 brGDGT 在文化中的研究，从而限制了这些分子作为古气候重建工具的使用。在这项工作中，我们使用受控的微观世界来研究温度和 pH 值对湖水中 brGDGT 的影响。我们的结果表明，温度对 brGDGT 的产生有很大影响，其敏感性与经验观察相似。相比之下，由于响应有限或实验设置，pH 实验产生了不确定的结果。