Collaborative Research: Do Cyanobacteria Drive Marine Hydrocarbon Biogeochemistry?

虽然石油碳氢化合物释放到海洋中被认为是对环境和人类的危害，但最近的一项研究估计，每年一个浮游植物群体（蓝细菌）释放的天然碳氢化合物对海洋表面碳氢化合物的贡献至少是其总量的十倍。该项目将是对这一巨大的生物烃池的潜在地球化学循环的第一次深入研究。通过实地研究，蓝细菌的实验室培养和最先进的化学分析，研究人员将研究分子结构，生产和去除的速率和机制，以及控制海洋碳氢化合物循环的环境条件。这项研究的结果将揭示重要的新知识，以提高对海洋中主要碳循环的理解。此外，数据可能表明，蓝藻碳氢化合物在准备天然海洋细菌应对和降解石油泄漏以及碳氢化合物库某些成分的海气交换可能造成的大气影响（如云的形成）方面发挥了作用。该项目将支持本科生和研究生，博士后研究员和新的教员，并将参与者从少数民族服务机构在加州和北卡罗来纳州。还包括与石油泄漏和生物燃料研究人员建立联系的计划，以评估这项研究所产生的数据的其他实际应用，最近报告了蓝藻每年产生3.08亿至7.71亿吨碳氢化合物，是溢油和自然渗漏产生的海洋石油碳氢化合物的10倍。 因此，这些生物源碳氢化合物几乎肯定对海洋中的碳循环和细菌群落组成有重大影响，但从未成为严格研究的主题。该项目将调查海洋中生物源碳氢化合物的分布、分配和循环，重点是与蓝藻种群有关的生物源碳氢化合物的丰度和分子多样性;挥发到大气中作为生物源碳氢化合物汇的程度;以及蓝藻产生碳氢化合物和碳氢化合物降解细菌消耗碳氢化合物的速率。浮游植物群落结构和丰度的自然梯度实地研究将采用最先进的化学分析来评价生物碳氢化合物的分布，并与孵化实验一起确定海洋表层生物碳氢化合物循环的定量速率。实验室研究将通过在严格控制的实验室条件下评估碳氢化合物的生产和损失机制来加强实地研究。 总之，该项目将获得对海洋碳循环这一重要组成部分的定量了解。

While the release of petroleum hydrocarbons into the ocean is recognized as an environmental and human hazard, a recent study has estimated that on an annual basis, the release of natural hydrocarbons by a single phytoplankton group (cyanobacteria) contributes at least ten times more total hydrocarbon to the surface ocean. This project will be the first in-depth study of the latent biogeochemical cycling of this huge pool of biogenic hydrocarbons. Using field studies, laboratory incubations of cyanobacteria, and state-of-the art chemical analysis, the researchers will examine the molecular structures, rates and mechanisms of production and removal, and the environmental conditions that control the cycling of this major pool of oceanic hydrocarbons. The results of this study will reveal significant new knowledge for improved understanding of a major carbon cycle in the ocean. Additionally, data could indicate a role for cyanobacterial hydrocarbons in preparing natural marine bacteria to respond to, and degrade petroleum spills, as well as a possible atmospheric impact (e.g. cloud formation) resulting from air-sea exchange of certain components of the hydrocarbon pool. This project will support undergraduate and graduate students, a postdoctoral investigator, and a new faculty member, and will engage participants from minority-serving institutions in California and North Carolina. Plans are also included to establish links with oil spill and biofuel researchers in order to evaluate additional practical applications for the data resulting from this study.The annual production of 308,000,000 - 771,000,000 tons of hydrocarbons by cyanobacteria has recently been reported and is a factor of 10 larger than marine petroleum hydrocarbon input from spills and natural seeps. Consequently, these biogenic hydrocarbons almost certainly have significant implications for the carbon cycle and the bacterial community composition in the ocean but have never been the subject of rigorous study. This project will investigate the distribution, partitioning, and cycling of biogenic hydrocarbons in the ocean, focusing on the abundance and molecular diversity of biogenic hydrocarbons in relation to cyanobacterial populations; the extent to which volatilization to the atmosphere acts as a sink for biogenic hydrocarbons; and the rate at which hydrocarbons are produced by cyanobacteria and consumed by hydrocarbon-degrading bacteria. Field studies across natural gradients in phytoplankton community structure and abundance will employ state of the art chemical analysis to evaluate the distribution of biogenic hydrocarbons, and together with incubation experiments will determine quantitative rates for biogenic hydrocarbons cycling in the surface ocean. Laboratory studies will augment field studies by assessing hydrocarbon production and loss mechanisms under carefully controlled laboratory conditions. Together, the project will obtain a quantitative understanding of this important component of the oceanic carbon cycle.