Microbial degradation of isoprene in the terrestrial environment

陆地环境中异戊二烯的微生物降解

基本信息

批准号：
NE/J009725/1
负责人：
John Murrell
金额：
$ 45.54万
依托单位：
University of East Anglia
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2012
资助国家：
英国
起止时间：
2012 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FJ009725%2F1
关键词：
Microbial degradation isoprene terrestrial environment

项目摘要

The Blue Mountains in Australia and Blue Ridge Mountains of Virginia, are so-named because of the blue haze that results from atmospheric reactions with isoprene, a gas produced in abundance by plants and especially many tree species. Trees that are starting to be grown widely as a source of bioenergy, namely willow and poplar, are among the highest isoprene emitters. Isoprene protects plants against heat and light-induced damage, and can also serve as a signaling molecule. Isoprene is so reactive with other chemicals in the lower atmosphere that it limits their capacity to react with methane and also generates ozone. Both ozone and methane are potent greenhouse gases, and ozone impairs plant growth. On the more positive side, isoprene can indirectly stimulate cloud formation which provides a cooling effect. Hundreds of studies have investigated isoprene production, primarily from trees, and examined the effect of a changing environment on its flux from tree to atmosphere. In stark contrast, only a handful of studies have shown that microbes in the soil consume isoprene, and a few of those microbes have been grown in the laboratory. Microbes are abundant (several billion per teaspoon of soil and more than a million per square cm of leaf) and the most important catalysts for cycling chemicals in the environment. We know from studying the cycles of other climatically important gases, like methane, that microbial consumption is an extremely important process that is greatly influenced by climate change. From hundreds of methane-consuming bacteria in culture, we have extensive knowledge of their metabolic pathways, which allows the development of investigative tools to help inform land-use management decisions. For isoprene, which is produced in similar abundance to methane, we lack this knowledge and tools.Therefore, in addition to those bacteria that we already have in culture, we propose to culture isoprene-degrading microbes, focusing on soil and leaf inhabitants. Using powerful genomic-based techniques, we will determine the DNA sequences of the genes involved in isoprene degradation. Additionally, we will use tools developed by the PI to identify and investigate those isoprene degraders that are not easy to grow. Most bacteria look alike and so we frequently use DNA sequences to study their roles in nature. Selected unique DNA sequences will be used to identify, view and count key species of isoprene-degrading bacteria in natural samples. This will enable us to determine precisely where they live, e.g. we envisage that they will be especially abundant around stomata (pores in the leaf) from where most isoprene escapes; and the use of state-of-the art imaging techniques (developed by our project partner) will allow us to identify which individual microbes are actively degrading isoprene in the soil or on the leaf surface.Complementing this study, a PhD student will measure isoprene consumption in forest soils, and for the first time, on leaves from various tree species, comparing isoprene emitters with non-emitters as well as sun and shade leaves. We will test whether adding permutations of isoprene-degrading microbes to leaf surfaces enhances consumption, and by measuring the microbes' ability to survive or grow on the leaves, we will obtain insights into whether this is a potential strategy for reducing isoprene flux. All of the data emanating from this project will be valuable for management of natural woodlands and bioenergy crops, in relation to greenhouse gas emissions.

澳大利亚的蓝山和弗吉尼亚州的蓝岭山脉之所以被命名，是因为蓝色阴霾是由与异戊二烯的大气反应产生的，这是一种植物，尤其是许多树种产生的气体。作为生物能源（即柳树和杨树）的来源，开始广泛种植的树木是最高的异戊二烯发射器之一。异戊二烯可保护植物免受热和光引起的损伤，也可以用作信号分子。异戊二烯与其他化学物质在较低的大气中具有反应性，以至于它们限制了它们与甲烷反应并产生臭氧的能力。臭氧和甲烷都是有效的温室气体，臭氧会损害植物的生长。在更积极的一面，异戊二烯可以间接刺激云形成，从而提供冷却效果。数百种研究主要来自树木的异戊二烯生产，并检查了环境对环境从树到大气的泛滥的影响。相比之下，只有少数研究表明土壤中的微生物消耗异戊二烯，其中一些微生物在实验室中生长。微生物丰富（每茶匙土壤几十亿，每平方厘米的叶子超过一百万），是环境中循环化学物质的最重要的催化剂。我们知道，从研究其他重要气体（例如甲烷）的周期中，微生物消耗是一个极为重要的过程，受到气候变化的极大影响。从文化中数百种甲烷耗尽的细菌中，我们对它们的代谢途径有广泛的了解，这使得开发研究工具可以帮助土地利用管理决策。对于与甲烷相似的异戊二烯，我们缺乏这种知识和工具。因此，除了我们在培养中已经拥有的细菌外，我们还建议培养降解的微生物，专注于土壤和叶子居民。使用强大的基于基因组的技术，我们将确定与异戊二烯降解有关的基因的DNA序列。此外，我们将使用PI开发的工具来识别和调查那些不容易生长的异戊二烯降解者。大多数细菌看起来都一样，因此我们经常使用DNA序列研究它们在自然界中的作用。选定的独特DNA序列将用于识别，观察和计算天然样品中降解细菌的关键种类。这将使我们能够准确确定它们的居住地，例如我们设想它们将在大多数异戊二烯逃逸的气孔（叶子中的毛孔）周围特别丰富。并且使用最先进的成像技术（由我们的项目合作伙伴开发）将使我们能够确定哪些单独的微生物正在积极地降解土壤中的异戊二烯或在叶子表面上。我们将测试是否将降解异戊二烯的微生物的排列添加到叶片表面上可以增强消耗量，并通过测量微生物在叶子上生存或成长的能力，我们将获得有关减少异戊二烯磁通的潜在策略的见解。与温室气体排放有关的天然林地和生物能源作物的管理，该项目发出的所有数据都将很有价值。

项目成果

期刊论文数量（10）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Draft Genome Sequences of Three Terrestrial Isoprene-Degrading Rhodococcus Strains.

DOI：
10.1128/genomea.01256-17
发表时间：
2017-11-09
期刊：
Genome announcements
影响因子：
0
作者：
Crombie AT;Emery H;McGenity TJ;Murrell JC
通讯作者：
Murrell JC

'Omics-guided prediction of the pathway for metabolism of isoprene by Variovorax sp. WS11.

DOI：
10.1111/1462-2920.16149
发表时间：
2022-11
期刊：
ENVIRONMENTAL MICROBIOLOGY
影响因子：
5.1
作者：
Dawson, Robin A.;Rix, Gregory D.;Crombie, Andrew T.;Murrell, J. Colin
通讯作者：
Murrell, J. Colin

The microbiology of isoprene cycling in aquatic ecosystems

DOI：
10.3354/ame01972
发表时间：
2021-06-01
期刊：
AQUATIC MICROBIAL ECOLOGY
影响因子：
1.4
作者：
Dawson, R. A.;Crombie, A. T.;Murrell, J. C.
通讯作者：
Murrell, J. C.

Gene probing reveals the widespread distribution, diversity and abundance of isoprene-degrading bacteria in the environment

DOI：
10.1186/s40168-018-0607-0
发表时间：
2018-12-07
期刊：
MICROBIOME
影响因子：
15.5
作者：
Carrion, Ornella;Larke-Mejia, Nasmille L.;Murrell, J. Colin
通讯作者：
Murrell, J. Colin

Regulation of plasmid-encoded isoprene metabolism in Rhodococcus, a representative of an important link in the global isoprene cycle.

DOI：
10.1111/1462-2920.12793
发表时间：
2015-09
期刊：
Environmental microbiology
影响因子：
5.1
作者：
Crombie AT;Khawand ME;Rhodius VA;Fengler KA;Miller MC;Whited GM;McGenity TJ;Murrell JC
通讯作者：
Murrell JC