OCE-PRF: Alkane-based metabolic coupling between phytoplankton and Marine Group II Euryarchaeota

该奖项全部或部分由《2021年美国救援计划法案》（公法117-2）资助。石油碳氢化合物通过自然途径进入海洋，如从地质层渗漏，以及人为来源，如与石油开采、运输和消费相关的工业石油泄漏。生物烃（或隐生微生物烃）起源于浮游植物（蓝藻和其他微藻），以长链烷烃和烯烃的形式释放到海洋中，并且以大量和快速的循环释放到海洋中，远远超过所有其他海洋石油输入。海洋中缺乏生物碳氢化合物的积累表明它们被微生物网络有效地消耗了。然而，对于这些化合物在阳光照射的海洋中的命运，目前还存在一个重大的知识缺口，而大部分生物碳氢化合物的消耗都发生在阳光照射的海洋中。这项工作旨在为理解不同海洋环境下生物烃的产生和生物降解奠定科学基础，并了解生物烷烃循环如何在海洋对破坏性海洋溢油灾害的反应中发挥作用。这里提出的具体研究源于最近的发现，即发现海洋中普遍存在的生物碳氢化合物循环，以及发现海洋II (MGII) Euryarchaeota广泛拥有碳氢化合物降解酶机制的基因组能力，我们直接观察到自然界中丰富的特定基因。为了探索这些观察结果之间的联系，我提出了三个可测试的假设，重点关注MGII对生物源烷烃的吸收，MGII种群反映环境碳氢化合物供应的程度，以及MGII是否能够在以全石油为基质时开花。该方法包括与先前资助的考察同时进行的实地研究，利用太平洋和墨西哥湾的天然石油渗漏，与两个当地海洋时间序列采样项目（羽流和华流和圣佩德罗海洋时间序列）相结合，并结合以MGII动态为中心的生物烷烃实验室研究。为了获得更广泛的影响和教育机会，这项研究包括在整个项目期间对多名本科生进行培训，并将在先前资助的探险中进行实地工作，在同位素和微生物技术的实验室体验，并参加一次重要的海洋科学会议。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).Petroleum hydrocarbons enter the ocean via natural means—such as seepage from geologic strata—as well as from anthropogenic sources, such as industrial oil spills associated with extraction, transportation, and consumption of petroleum. Biogenic hydrocarbons (or cryptic microbial hydrocarbons) originate from phytoplankton (cyanobacteria and other microalgae) in the form of long-chain alkanes and alkenes, and are also released into the ocean in a massive and rapid cycle that greatly exceeds all other marine petroleum inputs. The lack of biological hydrocarbon accumulation in the ocean points to their efficient consumption by networks of microorganisms. However, there is currently a major knowledge gap on the fate of these compounds in the sunlit ocean where the majority of biogenic hydrocarbon consumption occurs. This work seeks to lay a scientific foundation for understanding the production and biodegradation of biogenic hydrocarbons in contrasting oceanic environments, and to inform how biogenic alkane cycles play a role in structuring the ocean’s response to devastating marine oil spill disasters. The specific research proposed here derives from a combination of recent discoveries, namely the discovery of a pervasive biological hydrocarbon cycle in the ocean, described above, and the discovery that Marine Group II (MGII) Euryarchaeota broadly harbor the genomic capacity for hydrocarbon-degrading enzymatic machinery, specific genes which we directly observe abundant in nature. To explore the linkage between these observations, I have developed three testable hypotheses that focus on the uptake of biogenic alkanes by MGII, the extent to which MGII populations reflect ambient hydrocarbon supply, and whether MGII is capable of blooming when fed whole petroleum as substrate. This approach involves field studies conducted in tandem with a previously funded expedition, leverages access to natural oil seeps in the Pacific and Gulf of Mexico, ties-in to two local ocean time-series sampling programs (Plumes and Blooms and San Pedro Ocean Time Series), and incorporates laboratory studies centered on MGII dynamics in relation to biogenic alkanes. Toward broader impacts and educational opportunities, this research includes training of multiple undergraduate students over the entire duration of the project and the experience will include field work on a previously funded expedition, laboratory experience with isotopic and microbial techniques, and participation in a major ocean sciences meeting.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.