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Sequencing the Sea Sulphur Cycle

对海硫循环进行测序

基本信息

批准号：
NE/F001312/1
负责人：
Andrew Johnston
金额：
$ 7.15万
依托单位：
University of Warwick
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%2FF001312%2F1
关键词：
Sequencing Sea Sulphur Cycle

项目摘要

Picture this. A molecule, quite a simple one, which charms the sea birds in distant seas, which makes tiny shrimps tumble in excitement at getting their lunch and, which causes the billowing clouds to form over the far-flung oceans. And, as if that were not enough, every time you stroll by the seaside, that tangy, evocative aroma is due not to the ozone your parents told you about, or the Calvin Klein 'Ocean' deodorant in 'Seinfeld' (listen to; http://podcast.sciam.com/daily/sa_d_podcast_070209.mp3), but to this marvellous little substance, a gas called DIMETHYL SULPHIDE. The rather unlikely starting point for this remarkable compound is another molecule, called Dimethylsulphiopropionate (DMSP for short) which is used by huge numbers of marine plankton and seaweeds as an anti-stress protectant. When these plants die, they release the DMSP and this is then latched onto by bacteria, which break it down, using part of it for their carbon and sulphur food requirements. Worldwide, this occurs at a prodigious scale, with more than 400 million tonnes of DMSP being shifted by bacterial action every year. One product of the breakdown process is the magical DMS, some of which is released into the air, causing, among other things, the characteristic smell of the seaside. Remarkably, some ocean seabirds, such as petrels and shearwaters, sense the DMS as a marker for food supplies and home in on it from miles away. And, on a different scale, tiny, but hugely abundant shrimp-like creatures called copepods can also use DMS to indicate nearby food supplies. More important, though, DMS is further modified in the atmosphere, to sulfate aerosols, which act as nucleating agents to form clouds over the oceans, in the same way (sort of) as one gets crystals to grow in a crystal garden by starting off with a 'seed'. This has major effects on global climate and was even used by that sage, James Lovelock, as a plank to underpin his 'Gaia Hypothesis'. Although the production and subsequent conversions of DMS are hugely important, in many ways, we know very little about how these processes occur, at least at molecular levels. However, recent work by the applicants has unravelled at least some of the steps by which DMS is made and by which it is then transformed into other sulphurous compounds. Very suprisingly, though, that work also showed that there are several different ways in which different species of marine bacteria can undertake these reactions. So, we now wish to know the entire genetic makeup of these intriguing, and important bacteria so that we can unravel just what lies behind their remarkable metabolic flexibility. By having the entire sequences of their genomes, we will have a great set of resources to help us, and others in the marine microbiology world, to understand far better what is going on, at a local and a global level in the formation and biochemical and environmental fate of the DMS gas.

想象一下。一种分子，很简单的一种分子，它能使遥远的海洋中的海鸟着迷，使小虾在吃午饭时兴奋地翻滚，使遥远的海洋上形成滚滚的云层。而且，好像这还不够，每次你在海滨漫步时，那种刺鼻的、令人回味的香味不是因为你父母告诉你的臭氧，也不是因为《宋飞正传》（Seinfeld）中的卡尔文克莱恩（Calvin Klein）“海洋”除臭剂（请听; http：//podcast.sciam.com/daily/sa_d_podcast_070209.mp3），而是因为这种奇妙的小物质，一种叫做二甲基硫的气体。这种非凡化合物的起点是另一种分子，称为二甲基硫基丙酸酯（简称DMSP），它被大量海洋浮游生物和海藻用作抗应激保护剂。当这些植物死亡时，它们释放出DMSP，然后细菌将其分解，并将其部分用于碳和硫的食物需求。在世界范围内，这种情况发生在一个巨大的规模，超过4亿吨的DMSP被转移的细菌行动，每年。分解过程的产物之一是神奇的二甲基硫醚，其中一些被释放到空气中，造成了海滨特有的气味。值得注意的是，一些海洋海鸟，如海燕和海鸥，感觉到DMS作为食物供应的标志，并在几英里外找到它。而且，在不同的尺度上，微小但数量巨大的虾状生物桡足类也可以使用DMS来指示附近的食物供应。然而，更重要的是，DMS在大气中被进一步改变为硫酸盐气溶胶，它作为成核剂在海洋上形成云，就像人们从“种子”开始在水晶花园中生长水晶一样。这对全球气候有重大影响，甚至被圣人詹姆斯·洛夫洛克用作支撑他的“盖亚假说”的木板。虽然DMS的产生和随后的转化非常重要，但在许多方面，我们对这些过程如何发生知之甚少，至少在分子水平上是这样。然而，申请人最近的工作至少解开了DMS的制备步骤以及将其转化为其他含硫化合物的步骤。然而，非常令人惊讶的是，这项工作还表明，不同种类的海洋细菌可以通过几种不同的方式进行这些反应。因此，我们现在希望了解这些有趣而重要的细菌的整个基因组成，以便我们能够揭开它们非凡的代谢灵活性背后的秘密。通过获得它们基因组的全部序列，我们将拥有一系列丰富的资源，帮助我们和海洋微生物学领域的其他人更好地了解在地方和全球层面上发生了什么，在形成和生物化学和环境命运的DMS气体。