Beyond the unsaturation ratios (UK37' or UK37) of long chain alkenones: unlocking the hidden treasure trove of alkenone-producing haptophytes

超越长链烯酮的不饱和比（UK37或UK37）：解锁产烯酮触生菌的隐藏宝库

• 批准号: 1762431
• 负责人: Yongsong Huang
• 金额: $ 33.44万
• 依托单位: Brown University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1762431&HistoricalAwards=false
• 关键词: Beyond; unsaturation; ratios; UK37; long

The proposed research aims to bring and calibrate a new set of molecular tools that permit a more in-depth and quantitative understanding of underlying mechanism driving climate variations. The new molecular tools will overcome the problems of the existing methods that are extremely problematic in ocean settings close to continental margins and estuaries because of entangled molecular signals. Once calibrated, the new molecular indices will provide new ways to study past temperature variations at unprecedented details. The research also has great potential to establish novel molecular approaches that allow quantitative assessment of changes in sea surface salinity - a very important indicator of regional hydrological changes. The study will also greatly advance our understanding of biochemistry and genetic control of lipid biosynthesis in isochrysidales (a class of haptophyte algae that are among the most dominant photosynthetic organisms in the global oceans) in a wide range of ocean and continental environments. Specifically, lipids like alkenones and alkenoates are unique biomarkers produced by isochrysidales that not only permit quantitative past climate and environmental reconstructions, but are also regarded as among the top candidates for biodiesel production using algal biomass in the near future. The funds will also support graduate students who, together with the PIs, actively participate in a wide range of broad-impact activities such as teaching science at local GK-12 schools, many of which have substantial population of underrepresented minorities. The technical merit of the research can be summarized as follows. The unsaturation ratios (UK37' or UK37) of long chain alkenones (LCAs) are among the most successful paleo-sea surface temperature (SST) proxies ever developed, and have been widely applied for over three decades. A recent study by the PI, however, suggests that the true power of this important class of biomarkers has yet to be fully unleashed. For example, a newly discovered freshwater/oligosaline haptophyte species with characteristic alkenone profiles distinct from marine and saline water counterparts open up new opportunities for quantitative continental paleoclimate studies. Important recent progress made by the research team in both gas and liquid chromatographic separation of alkenones/alkenoates permits accurate, comprehensive and simultaneous quantification of up to 32 alkenones, alkenoates and their structural isomers (~5 - 10 times more compounds than old analytical methods) and a corresponding new suite of SST proxies based on isomeric ratios and non-C37 alkenones. These developments promise to extend alkenone proxies to previously inaccessible regions, including: 1) marginal seas where alkenones are contributed by both open-ocean and coastal species; 2) high latitude regions where alkenone concentrations are low and the traditional alkenone-temperature relationship fails. Comprehensive biomarker profiling has great potential to refine chemotaxonomic differentiation of different groups/species of alkenone-producing haptophytes, with implications for quantitative apportionment of species inputs in mixed aquatic settings and assessing past sea surface salinity (SSS) changes. This proposal aims to systematically analyze a large suite of core top ocean sediments, and to culture selected haptophyte species/key strain varieties, to calibrate the new SST and SSS proxies and to establish high quality biomarker profiles for chemotaxonomy.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

拟议的研究旨在引入并校准一套新的分子工具，以便更深入和定量地了解驱动气候变化的潜在机制。新的分子工具将克服现有方法的问题，这些问题在靠近大陆边缘和河口的海洋环境中由于分子信号的纠缠而存在极大的问题。一旦校准，新的分子指数将提供新的方法来以前所未有的细节研究过去的温度变化。该研究还具有建立新的分子方法的巨大潜力，可以定量评估海面盐度的变化 - 这是区域水文变化的一个非常重要的指标。这项研究还将极大地增进我们对广泛海洋和大陆环境中等鞭藻类（全球海洋中最主要的光合生物之一）脂质生物合成的生物化学和遗传控制的理解。具体来说，烯酮和烯酸盐等脂质是等菊目产生的独特生物标志物，不仅可以定量重建过去的气候和环境，而且还被认为是在不久的将来使用藻类生物质生产生物柴油的最佳候选者之一。这些资金还将支持研究生与 PI 一起积极参与广泛影响广泛的活动，例如在当地 GK-12 学校教授科学，其中许多学校都有大量代表性不足的少数族裔。该研究的技术优点可概括如下。长链烯酮 (LCA) 的不饱和比（UK37' 或 UK37）是迄今为止开发的最成功的古海表面温度 (SST) 指标之一，并已广泛应用了三十多年。然而，PI 最近的一项研究表明，这一类重要生物标志物的真正力量尚未完全释放。例如，新发现的淡水/低聚盐生植物物种具有与海洋和咸水对应物不同的特征性烯酮特征，为定量大陆古气候研究开辟了新的机会。研究团队最近在烯酮/烯酸酯的气相和液相色谱分离方面取得的重要进展，可以准确、全面、同时定量多达 32 种烯酮、烯酸酯及其结构异构体（比旧分析方法多约 5 - 10 倍的化合物）以及基于异构比率和非 C37 烯酮的相应新 SST 代理套件。这些进展有望将烯酮代理扩展到以前无法进入的地区，包括：1）边缘海，其中烯酮由公海和沿海物种共同贡献； 2）高纬度地区，其中烯酮浓度较低，传统的烯酮与温度关系失效。全面的生物标志物分析对于细化不同类群/物种的产烯酮附着体的化学分类学分化具有巨大的潜力，对混合水生环境中物种输入的定量分配和评估过去的海面盐度（SSS）变化具有影响。该提案旨在系统地分析大量核心顶部海洋沉积物，培养选定的附着植物物种/关键菌株品种，校准新的 SST 和 SSS 代理，并建立高质量的化学分类学生物标志物谱。该奖项反映了 NSF 的法定使命通过使用基金会的智力价值和更广泛的影响审查标准进行评估，并被认为值得支持。

项目成果

Systematic chemotaxonomic profiling and novel paleotemperature indices based on alkenones and alkenoates: Potential for disentangling mixed species input

• DOI: 10.1016/j.orggeochem.2018.12.008
• 发表时间: 2019-02
• 期刊: Organic Geochemistry
• 影响因子: 3
• 作者: Yinsui Zheng;P. Heng;M. Conte;R. Vachula;Yongsong Huang

Group 1 phylogeny and alkenone distributions in a freshwater volcanic lake of northeastern China: implications for paleotemperature reconstructions

• DOI: 10.1016/j.orggeochem.2022.104483
• 发表时间: 2022-08
• 期刊: Organic Geochemistry
• 影响因子: 3
• 作者: Lu Wang;Yuanjun Yao;Yongsong Huang;Yanjun Cai;Hai Cheng

Pre‐Industrial (1750–1850 CE) Cold Season Warmth in Northeastern China

• DOI: 10.1029/2023gl103591
• 发表时间: 2023-05
• 期刊: Geophysical Research Letters
• 影响因子: 5.2
• 作者: Y. Yao;Lu Wang;Yongsong Huang;Jie Liang;R. Vachula;Yanjun Cai;Hai Cheng

Impacts of Norse settlement on terrestrial and aquatic ecosystems in Southwest Iceland

• DOI: 10.1007/s10933-020-00169-3
• 发表时间: 2021-01
• 期刊: Journal of Paleolimnology
• 影响因子: 2.1
• 作者: N. Richter;J. Russell;J. Garfinkel;Yongsong Huang

Phylogenetic diversity in freshwater‐dwelling Isochrysidales haptophytes with implications for alkenone production

• DOI: 10.1111/gbi.12330
• 发表时间: 2019-02
• 期刊: Geobiology
• 影响因子: 3.7
• 作者: N. Richter;W. Longo;S. George;A. Shipunova;Y. Huang;L. Amaral-Zettler