Fast DMS Sensor for online quantification of dimethyl sulphide (DMS)

用于在线定量二甲硫醚 (DMS) 的快速 DMS 传感器

基本信息

批准号：
NE/H012567/1
负责人：
Michael Steinke
金额：
$ 6.94万
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：
2010
资助国家：
英国
起止时间：
2010 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FH012567%2F1
关键词：
Fast DMS Sensor online quantification

项目摘要

Dimethyl sulphide (DMS) is a trace gas produced in marine environments that gives the ocean the typical 'smell of the sea'. Its concentrations in seawater and in air samples have been monitored for many years, since research demonstrated that DMS is responsible for making clouds in the remote marine atmosphere. Of course, this is important for our understanding of climate and future global change. In contrast to this global significance, we know very little about how, when and why DMS is produced. Most of the DMS is enzymatically cleaved from dimethylsulphoniopropionate (DMSP), a compound that many algae use as an osmolyte to survive in high salt environments. Conventional methodology (purge-and-trap coupled to gas chromatography) to quantify DMS in seawater and air is laborious and time-consuming. As a result, we currently lack high-resolution data on the production of DMS in algal cultures. We hypothesise that DMS production is variable over the day and sensitive to environmental stress such as high light conditions. Methodology using chemiluminescence detection of DMS for high resolution measurements in air exists but this technology has not been used to address physiological aspects of DMS production in water. We conducted DMS measurements in the water and in the waste air from aerated chemostat cultures of the globally important and DMS-producing alga Emiliania huxleyi. The aeration efficiently purges most of the DMS out of the water and transfers this gas into the air stream. As a result, the DMS concentrations in the waste air provide an accurate measurement of DMS production. Since the DMS concentrations in the waste air are relatively high (2 to 40 parts per million) and other trace gases occur at relatively low concentrations, it is possible to use the ozone-induced chemiluminescence of DMS to continuously monitor the concentration of this compound. We already tested a commercially available chemiluminescence detector (Fast Isoprene Sensor) for DMS and found a linear response to DMS in the parts per billion to parts per million concentration range. This is encouraging and suggests that this instrument could be readily used for our application. We propose to optimise and test the Fast Isoprene Sensor for our DMS measurements. A series of experiments using chemostats with continuous cultures of E. huxleyi will be used to address DMS production under steady-state conditions before perturbing the system with short periods of increased light intensity (in the visible and ultraviolet spectrum). Light has been shown to affect DMS production in E. huxleyi, and it is thought that DMS functions as an antioxidant and assists with the removal of harmful reactive oxygen species that are produced under high light conditions. However, the dynamics of DMS production under such stressful conditions are unknown. Our project will deliver new information on DMS production in E. huxleyi. It will further test an online chemiluminescence detector for inexpensive continuous monitoring of DMS-production in algal cultures. We envisage that this high-resolution methodology will be used in future grant applications that will address DMS-production from various organisms including other phytoplankton species, macroalgae, fungi and bacteria.

二甲基硫化物（DMS）是在海洋环境中产生的微量气体，使海洋典型的“气味”。自从研究表明，DMS负责在偏远的海洋大气中造成云，它在海水和空气样品中的浓度已经受到了多年的监测。当然，这对于我们对气候和未来全球变化的理解非常重要。与这种全球意义相反，我们对如何，何时以及为什么生产DM的了解一无所知。大多数DMS在酶上是从二甲基磺酸二丙酸酯（DMSP）裂解的，这是一种化合物，许多藻类用作在高盐环境中生存的渗透剂。常规方法（与气相色谱与气相色谱法耦合）以量化海水和空气中的DMS是费力且耗时的。结果，我们目前缺乏有关藻类培养物中DMS产生的高分辨率数据。我们假设DMS的生产在一天中是可变的，并且对环境压力（例如高光条件）敏感。存在使用DMS化学发光检测进行空气中的高分辨率测量的方法，但该技术尚未用于解决水中DMS生产的生理方面。我们在水中进行了DMS测量，并在全球重要的和DMS生产的藻类艾米利亚氏菌的充气化学恒定培养物中进行了废气。曝气有效地从水中清除了大多数DM，并将这种气体转移到空气流中。结果，废气中的DMS浓度可以准确地测量DMS生产。由于废气中的DMS浓度相对较高（每百万份2至40份），而其他痕量气体则以浓度相对较低，因此可以使用臭氧诱导的DMS化学发光来连续监测该化合物的浓度。我们已经测试了DMS的市售化学发光检测器（快速异戊二烯传感器），并发现对DMS的零件的线性响应，即每十亿零件到每百万个浓度范围。这令人鼓舞，并表明该工具可以很容易地用于我们的应用。我们建议对DMS测量进行优化和测试快速异戊二烯传感器。一系列使用与绿o。Huxleyi的连续培养的化学稳定物的实验将用于在稳态条件下解决DMS的生产，然后再扰动系统的光强度增加（在可见光和紫外线光谱中）。已显示光线会影响Huxleyi大肠杆菌的DMS产生，并且认为DMS是抗氧化剂的作用，并有助于去除在高光条件下产生的有害活性氧。但是，在这种压力条件下，DMS产生的动态尚不清楚。我们的项目将在E. Huxleyi中提供有关DMS生产的新信息。它将进一步测试在线化学发光探测器，以廉价地对藻类培养物中的DMS产生进行廉价监测。我们设想，这种高分辨率方法将用于未来的赠款应用中，该应用将解决来自各种生物的DMS生产，包括其他浮游植物，大藻类，真菌和细菌。