Regulation of isoprene production by coastal benthic communities

沿海底栖群落异戊二烯生产的调控

• 批准号: NE/F010184/1
• 负责人: David Suggett
• 金额: $ 4.51万
• 依托单位: University of Essex
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2008
• 资助国家: 英国
• 起止时间: 2008 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FF010184%2F1
• 关键词: Regulation; isoprene; production; coastal; benthic

Isporene (2-methyl-1,3-butadiene) is one of several volatile organic compounds produced by micro-organisms but is of particular interest since it is one of the most highly reactive hydrocarbons emitted that can alter the our climate. Isoprene rapidly oxidises when released to the atmosphere, which in turn lengthens the residence times of gases that contribute to the 'greenhouse' affect, and induces formation of ozone (in presence of nitric oxides) and cloud-condensing nuclei. To date, international attention of global isoprene fluxes has focused primarily on terrestrial systems whilst aquatic systems have been largely ignored. Estimates for global isoprene emissions from marine systems are thought to be substantially lower than those from terrestrial systems. However, these estimates from marine systems have been constructed from few laboratory-based studies upon microalgae. Recent research conducted in the field suggests that isoprene emissions from marine waters may be higher than previously estimated, in particular during microalgal blooms. Nevertheless, the focus of the limited previous research investigating isoprene emissions from marine systems has neglected two key factors that likely determine its global importance: (1) production by highly productive coastal marine communities and (2) the dynamics underlying both isoprene synthesis and degradation. Isoprene is synthesised by plants, algae and bacteria, all of which are abundant across the fringing, and permanently submerged habitats of coastal waters. Coastal marine systems cover a relatively small fraction of the earth's surface yet are highly productive (accounting 25% of all aquatic production). Simultaneously, these systems subject their inhabitants to continuously (and often extreme) fluctuating environmental conditions, such as light and temperature; such a highly variable growth environment is known to induce elevated isoprene synthesis in terrestrial systems. Both tropical and temperate marine coastal systems are characterised by analogous functional groups that likely synthesis substantial concentrations of isoprene, for example saltmarshes, macroalgae and microalgae (temperate) and mangroves, corals and seagrasses (tropical). However, not all isoprene that is synthesised is thought to reach the atmosphere. Degradation of isoprene by heterotrophic bacteria in soils has also been identified as an important component contributing to net isoprene emissions from terrestrial systems. Recent microcosm experiments at the University of Essex have demonstrated substantial isoprene degradation along an estuarine gradient and thus the occurrence of a marine sink for gross isoprene production. Here, we propose a curiosity-driven but proof-of-concept investigation to address this unknown importance of isoprene synthesis and degradation within coastal marine systems. Data collected here will directly form the basis of a future full proposal that will examine the mechanistics and biological interactions if net isoprene production and emission by marine systems. Within the context of this study, we have proposed the purchase of a commercially available field-operable Fast Isoprene Sensor (FIS, Hill Scientific, USA) and use this instrument for the first time for assaying marine communities in both laboratory and field settings. Therefore, this proposal will also determine the capabilities of the FIS for assaying aquatic organisms and for generating rapid field-based measurements. Experiments are described that will employ short- and long- term incubation experiments for a wide range of aquatic organisms that are commonly found within temperate and tropical coastal marine systems.

异孢烯（2-甲基-1,3-丁二烯）是微生物产生的几种挥发性有机化合物之一，但由于它是排放的活性最高的碳氢化合物之一，可以改变我们的气候，因此受到特别关注。异戊二烯释放到大气中后会迅速氧化，从而延长造成“温室”影响的气体的停留时间，并诱导臭氧（存在一氧化氮）和云凝核的形成。迄今为止，国际上对全球异戊二烯通量的关注主要集中在陆地系统，而水生系统在很大程度上被忽视。据认为，海洋系统的全球异戊二烯排放量远低于陆地系统的排放量。然而，这些来自海洋系统的估计是根据一些基于实验室的微藻研究而构建的。最近在该领域进行的研究表明，海水中的异戊二烯排放量可能高于之前的估计，特别是在微藻大量繁殖期间。然而，先前对海洋系统异戊二烯排放的有限研究的重点忽略了可能决定其全球重要性的两个关键因素：（1）高生产力的沿海海洋群落的生产和（2）异戊二烯合成和降解的动态。异戊二烯由植物、藻类和细菌合成，这些物质在沿海水域的边缘和永久淹没的生境中含量丰富。沿海海洋系统覆盖地球表面相对较小的部分，但生产力很高（占所有水产产量的 25%）。同时，这些系统使其居民面临持续（且通常是极端）波动的环境条件，例如光照和温度；已知这种高度可变的生长环境会诱导陆地系统中异戊二烯的合成增加。热带和温带海洋沿海系统都具有类似的功能群，可能合成大量异戊二烯，例如盐沼、大型藻类和微藻（温带）以及红树林、珊瑚和海草（热带）。然而，并非所有合成的异戊二烯都被认为会到达大气中。土壤中异养细菌对异戊二烯的降解也被认为是陆地系统异戊二烯净排放的重要组成部分。埃塞克斯大学最近的微观实验表明，异戊二烯沿着河口梯度发生大量降解，从而出现了异戊二烯总产量的海洋汇。在这里，我们提出了一项好奇心驱动但概念验证的研究，以解决沿海海洋系统中异戊二烯合成和降解的未知重要性。这里收集的数据将直接构成未来完整提案的基础，该提案将检查海洋系统净异戊二烯生产和排放的机制和生物相互作用。在本研究的背景下，我们建议购买市售的可现场操作的快速异戊二烯传感器（FIS，Hill Scientific，美国），并首次使用该仪器在实验室和现场环境中分析海洋群落。因此，该提案还将确定 FIS 分析水生生物和生成快速现场测量结果的能力。描述的实验将对温带和热带沿海海洋系统中常见的各种水生生物进行短期和长期孵化实验。

项目成果

Application of a Fast Isoprene Sensor (FIS) for measuring isoprene production from marine samples

应用快速异戊二烯传感器 (FIS) 测量海洋样品中的异戊二烯产量

• DOI: 10.4319/lom.2010.8.185
• 发表时间: 2010
• 期刊: LIMNOLOGY AND OCEANOGRAPHY-METHODS
• 影响因子: 2.7
• 作者: Exton Dan A.

Spatial and temporal variability of biogenic isoprene emissions from a temperate estuary

• DOI: 10.1029/2011gb004210
• 发表时间: 2012-05-08
• 期刊: GLOBAL BIOGEOCHEMICAL CYCLES
• 影响因子: 5.2
• 作者: Exton, D. A.;Suggett, D. J.;McGenity, T. J.
• 通讯作者: McGenity, T. J.