Alkenone-producing species have been recently found in diverse lacustrine environments, albeit with taxonomic information derived indirectly from environmental genomic techniques. In this study, we isolated alkenone-producing algal species from Canadian saline lakes and established unialgal cultures of individual strains to identify their taxonomical and molecular biological characteristics. Water and sediments collected from the lakes were first enriched in artificial seawater medium over a range of salinities (5–40 ppt) to cultivate taxa in vitro. Unialgal cultures of seven haptophyte strains were isolated and categorized in the Isochrysis clade using SSU and LSU rRNA gene analysis. The alkenone distributions within isolated strains were determined to be novel compared with other previously reported alkenone-producing haptophytes. While all strains produced the typical C₃₇ and C₃₈ range of isomers, one strain isolated from Canadian salt lakes also produced novel C₄₁ and C₄₂ alkenones that are temperature sensitive. In addition, we showed that all alkenone unsaturation indices (e.g., $U_{37}^K$ and $U_{37}^{K\prime }$) are temperature-dependent in culture experiments, and that alkenoate indices (e.g., $U_{37}^A$, $U_{38}^A$, RIA₃₈ and A₃₇/A₃₈) provide alternative options for temperature calibration based on these new lacustrine algal strains. Importantly, these indices show temperature dependence in culture experiments at temperatures below 10 °C, where traditional alkenone proxies were not as sensitive. We hypothesize that this suite of calibrations may be used for reconstructions of past water temperature in a broad range of lakes in the Canadian prairies.

尽管具有从环境基因组学技术间接获得的分类学信息，但近来已在各种各样的湖泊环境中发现了生产烯酮的物种。在这项研究中，我们从加拿大盐湖中分离出了生产烯酮的藻类，并建立了单个菌株的单藻培养物，以鉴定其分类学和分子生物学特征。从湖泊收集的水和沉积物首先在一定范围的盐度（5–40 ppt）中富含人工海水介质，以在体外培养类群。7定鞭藻门菌株的培养Unialgal分离并在分类球等鞭金进化枝使用SSU和LSU rRNA基因分析。与其他先前报道的产生烯酮的触觉植物相比，分离株中烯酮的分布被确定为是新颖的。尽管所有菌株均产生典型的C ₃₇和C ₃₈异构体，但从加拿大盐湖分离出的一种菌株也产生了对温度敏感的新型C ₄₁和C ₄₂烯酮。此外，我们显示了所有烯酮不饱和指数（例如，${ü}_{37}^{ķ}$ 和 ${ü}_{37}^{ķ\prime }$）在培养实验中与温度相关，并且烯酸指数（例如， ${ü}_{37}^{\mathrm{一个}}$， ${ü}_{38}^{\mathrm{一个}}$，RIA ₃₈和A ₃₇ / A ₃₈）提供了基于这些新的湖相藻类菌株进行温度校准的替代方法。重要的是，这些指标在低于10°C的温度下的培养实验中显示出温度依赖性，而传统的烯酮类药物对温度的依赖性不高。我们假设这套校准可用于重建加拿大大草原中众多湖泊的过去水温。