Is bacterial DMS consumption dependent on methylamines in marine waters?

细菌 DMS 消耗量是否取决于海水中的甲胺？

• 批准号: NE/R010382/1
• 负责人: Joanna Dixon
• 金额: $ 46.13万
• 依托单位: Plymouth Marine Laboratory
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2018
• 资助国家: 英国
• 起止时间: 2018 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FR010382%2F1
• 关键词: bacterial; DMS; consumption; dependent; methylamines

Dimethylsulfide (DMS) is a key ingredient in the cocktail of gases that makes up the 'smell of the sea'. Around 300 million tons of DMS are formed each year by single-celled organisms in the surface ocean. A small proportion (up to 16%) of this DMS is released into the atmosphere, forming cloud-seeding compounds which can influence our weather and climate. When it rains, sulfur compounds are deposited back into the soils of our continents. However, most of the DMS formed in the oceans stays there, facing consumption by marine microbes and conversion to another sulfur compound - dimethylsulfoxide (DMSO). DMSO is usually the most abundant organic sulfur compound in the oceans and represents a major pool of the essential life elements sulfur and carbon.Seawater contains a rich mixture of important chemical nutrients that support the entire oceanic food web. The dissolved organic nitrogen pool is a chemical 'drive thru' which contains the highly reactive N-osmolytes: glycine betaine, choline and trimethylamine N-oxide. These chemicals are used by microorganisms to protect them from changes in their environmental conditions, such as variability in the saltiness of the surrounding seawater, and to protect their cells from chemical or physical damage. When N-osmolytes breakdown they can release gases such as methylamines into the atmosphere which can influence the climate.We have found a previously unrecognised and intriguing link between the bacterial breakdown of organic nitrogen compounds, like methylamines, and organic sulfur compounds like DMS. This link is provided by a bacterial enzyme called trimethylamine monooxygenase (Tmm). Tmm simultaneously removes both methylamines and DMS from seawater (converting it to DMSO). In fact we think this production of DMSO doesn't happen without the presence of methylamines. We estimate that up to 20% of all bacteria in our oceans contain this particular enzyme. The research we want to carry out will firstly investigate this link between DMS removal and methylamine availability in 'model' micro-organisms in the laboratory, checking that this link is active and how it is controlled in key marine bacteria commonly found in the global oceans. We will next determine the importance of this process compared to other biological processes that consume DMS in seawater and put names to the microbes using this enzyme to remove DMS. We will study the microbial processes linking the organic sulfur and nitrogen cycles in the English Channel at a station that is sampled weekly as part of the Western Channel Observatory which is coordinated by Plymouth Marine Laboratory. This is a long-standing time series site for which a wealth of oceanographic and biological data are available (algal diversity, temperature, nutrients etc.; http://www.westernchannelobservatory.org.uk), which we will be able to use. A global model of particles in the atmosphere has recently suggested that changes in the location of DMS emissions, through climate-driven changes in the phytoplankton species distributions, could strongly influence our climate. We therefore want to investigate the link between DMS removal, the availability of organic nitrogen compounds like methylamines and phytoplankton species, which we can do at station L4, where phytoplankton species succession is understood and can be easily sampled.We will compare this temperate coastal region to one of the Earth's DMS hotspots - the Southern Ocean. The atmosphere above this remote and isolated ocean is pristine in comparison to the heavily polluted air of the Northern Hemisphere. Here, the connection between DMS produced in the oceans and our climate is thought to be the strongest. Given the important role of DMS, identifying the role of marine microorganisms and the pathways of DMS removal from seawater will provide key information that will improve our future understanding of how the sulfur cycle influences our climate.

二甲基硫（DMS）是混合气体中的关键成分，构成了“海洋气味”。海洋表层的单细胞生物每年形成约3亿吨二甲基硫醚。一小部分（高达16%）的DMS被释放到大气中，形成云催化化合物，可以影响我们的天气和气候。当下雨时，硫化合物会沉积到我们大陆的土壤中。然而，海洋中形成的大部分二甲基硫都留在那里，面临着海洋微生物的消耗并转化为另一种硫化合物--二甲基亚砜（DMSO）。二甲基亚砜通常是海洋中最丰富的有机硫化合物，代表着重要生命元素硫和碳的主要来源。海水含有丰富的重要化学营养物质，支持整个海洋食物网。溶解的有机氮池是一个化学的“驱动器通过”，其中包含高活性的N-渗透剂：甘氨酸甜菜碱，胆碱和三甲胺N-氧化物。这些化学物质被微生物用来保护它们免受环境条件的变化，例如周围海水盐度的变化，并保护它们的细胞免受化学或物理损伤。当氮渗透物分解时，它们会释放出甲胺等气体到大气中，从而影响气候。我们发现了细菌分解有机氮化合物（如甲胺）和有机硫化合物（如DMS）之间的一种以前未被认识到的有趣联系。这种连接是由一种叫做三甲胺单加氧酶（Tmm）的细菌酶提供的。Tmm同时从海水中去除甲胺和DMS（将其转化为DMSO）。事实上，我们认为如果没有甲胺的存在，DMSO的产生是不会发生的。我们估计，海洋中多达20%的细菌含有这种特殊的酶。我们想要开展的研究将首先调查实验室中“模型”微生物中二甲硫醚去除和甲胺可用性之间的联系，检查这种联系是否活跃，以及它如何在全球海洋中常见的关键海洋细菌中受到控制。接下来，我们将确定这一过程与消耗海水中DMS的其他生物过程相比的重要性，并为使用这种酶去除DMS的微生物命名。我们将研究微生物的过程连接在英吉利海峡的有机硫和氮循环在一个站，每周采样的一部分，西海峡天文台是由普利茅斯海洋实验室协调。这是一个历史悠久的时间序列网站，提供大量海洋学和生物学数据（藻类多样性、温度、营养物等; http://www.westernchannelobservatory.org.uk），我们将能够使用。一个全球大气颗粒模型最近表明，二甲基硫醚排放位置的变化，通过气候驱动的浮游植物物种分布的变化，可能会对我们的气候产生强烈影响。因此，我们希望调查DMS去除、有机氮化合物（如甲胺）的可用性和浮游植物物种之间的联系，我们可以在L4站进行调查，在那里可以了解浮游植物物种的演替，并且可以很容易地进行采样。我们将把这个温带沿海地区与地球DMS热点之一-南大洋进行比较。与北方半球严重污染的空气相比，这片遥远而孤立的海洋上方的大气是原始的。在这里，海洋中产生的二甲硫醚与我们的气候之间的联系被认为是最强的。鉴于二甲基硫的重要作用，确定海洋微生物的作用和从海水中去除二甲基硫的途径将提供关键信息，有助于我们今后更好地了解硫循环如何影响气候。

项目成果

Deltaproteobacteria (Pelobacter) and Methanococcoides are responsible for choline-dependent methanogenesis in a coastal saltmarsh sediment.

• DOI: 10.1038/s41396-018-0269-8
• 发表时间: 2019-03
• 期刊: The ISME journal
• 作者: Jameson E;Stephenson J;Jones H;Millard A;Kaster AK;Purdy KJ;Airs R;Murrell JC;Chen Y
• 通讯作者: Chen Y

The effects of changing sea ice conditions on microbial production and community composition in the Barents Sea

海冰条件变化对巴伦支海微生物生产和群落组成的影响

• 发表时间: 2022
• 作者: Downes P

Seasonal Changes in Microbial Dissolved Organic Sulfur Transformations in Coastal Waters.

沿海水域微生物溶解有机硫转化的季节变化。

• DOI: 10.3390/microorganisms8030337
• 发表时间: 2020
• 期刊: Microorganisms
• 影响因子: 4.5
• 作者: Dixon JL

Correction to: Seasonal measurements of the nitrogenous osmolyte glycine betaine in marine temperate coastal waters

修正：海洋温带沿海水域含氮渗透剂甘氨酸甜菜碱的季节性测量

• DOI: 10.1007/s10533-023-01023-0
• 发表时间: 2023
• 期刊: Biogeochemistry
• 影响因子: 4
• 作者: Airs R

Measurement of methylamines in seawater using solid phase microextraction and gas chromatography

• DOI: 10.1002/lom3.10255
• 发表时间: 2018-07-01
• 期刊: LIMNOLOGY AND OCEANOGRAPHY-METHODS
• 影响因子: 2.7
• 作者: Cree, Charlotte H. L.;Airs, Ruth;Fitzsimons, Mark F.
• 通讯作者: Fitzsimons, Mark F.