Impact of microorganisms as sinks of atmospheric chloromethane

微生物作为大气氯甲烷汇的影响

• 批准号: 258712308
• 负责人: Professor Dr. Frank Keppler
• 金额: --
• 依托单位: Institut für Geowissenschaften
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/258712308?language=en
• 关键词: Impact; microorganisms; sinks; atmospheric; chloromethane

An interdisciplinary consortium of two French and two German partners will combine their expertise and knowledge to address the impact of microorganisms on the global budget of chloromethane (CH3Cl). Anthropogenic emissions of ozone depleting compounds (CFcs) have been strongly reduced since the Montreal protocol came into force in 1989. As a consequence, compounds released from natural sources, such as CH3Cl, have become increasingly relevant in stratospheric ozone depletion. This chlorinated gas is the most abundant halogenated compound in the atmosphere whose primarily source is the terrestrial ecosystems. Release from living and dead vegetation and biomass burning are major sources. The positive linear response with temperature suggests that future warmer climates will likely lead to increased CH3Cl emissions. However, current estimates of the CH3Cl global budget are uncertain and suggest that microorganisms play a more important role in degrading atmospheric CH3Cl than previously thought. Methylotrophic microbes, some with the metabolic capability to degrade CH3Cl, occur in soils, the phyllosphere of many plants, and have recently been reported to be active in water droplets of clouds. The applicants conceive that the main objectives of the proposed project are to reveal quantitative information on process-level and to provide in depth genetic insights into these microbes. The consortium will investigate kinetic and isotope effects during CH3Cl degradation by methylotrophs associated with soils, plants, and clouds. Laboratory experiments with specific CH3Cl degrading methylotrophs will be conducted to measure their effects on isotope composition and to determine temperature effects on kinetic parameters. In various environmental samples the microbial community will be characterized using amplicon-targeted next generation sequencing employing a taxonomical (16S RNA genes) and a functional gene marker for CH3Cl degradation (cmuA). Selected samples of soil, plants, and cloud water will be subjected to 13C-isoptopologue of CH3Cl in order to label the biomass of CH3Cl converting microbes. Metagenomes will then be retrieved using a combination of DNA stable isotope probing, whole genome amplification, and MiSeq (Illumina) high throughput sequencing. These experiments will assess the diversity of the microbial CH3Cl-degrading pathways, and will enable the discovery of novel methyltransferases and further genes involved in CH3Cl metabolic transformation. The metagenomic approach will provide new insights into CH3Cl-degrading microbial communities of temperate terrestrial ecosystems and clouds. Kinetic and isotopic data will resolve the quantitative relevance of microbial sinks for the global CH3Cl budget. A improved quantitative understanding of the sources and sinks of atmospheric CH3Cl will be invaluable for enhancing our predictive capability for stratospheric chlorine chemistry and ozone layer stability.

一个由两个法国和两个德国合作伙伴组成的跨学科联合体将联合收割机结合其专长和知识，以解决微生物对全球氯甲烷（CH 3Cl）预算的影响。自1989年《蒙特利尔议定书》生效以来，人为排放的臭氧消耗化合物（CFCs）已大幅减少。因此，从自然来源释放的化合物，如CH 3Cl，在平流层臭氧消耗中变得越来越重要。这种氯化气体是大气中含量最丰富的卤代化合物，其主要来源是陆地生态系统。主要来源是活的和死的植被以及生物量燃烧。与温度的正线性响应表明，未来更温暖的气候可能会导致CH 3Cl排放量增加。然而，目前估计的CH 3Cl全球预算是不确定的，并建议微生物在降解大气CH 3Cl比以前认为的更重要的作用。甲基营养微生物，一些具有降解CH 3Cl的代谢能力，存在于土壤中，许多植物的叶际，最近有报道称在云中的水滴中很活跃。申请人认为，所提出的项目的主要目标是揭示工艺水平的定量信息，并提供对这些微生物的深入遗传见解。该财团将调查与土壤，植物和云相关的甲基营养生物降解CH 3Cl过程中的动力学和同位素效应。实验室实验与特定的CH 3Cl降解methylotrophs将进行测量同位素组成的影响，并确定温度对动力学参数的影响。在各种环境样品中，微生物群落将使用扩增子靶向的下一代测序，采用分类学（16 S RNA基因）和CH 3Cl降解功能基因标记（cmuA）进行表征。选定的土壤，植物和云水样品将进行13 C-同位素的CH 3Cl，以标记的CH 3Cl转化微生物的生物量。然后将使用DNA稳定同位素探测、全基因组扩增和MiSeq（Illumina）高通量测序的组合来检索宏基因组。这些实验将评估微生物CH 3Cl降解途径的多样性，并将能够发现新的甲基转移酶和参与CH 3Cl代谢转化的其他基因。宏基因组学方法将为温带陆地生态系统和云的CH 3Cl降解微生物群落提供新的见解。动力学和同位素数据将解决全球CH 3Cl预算的微生物汇的定量相关性。一个更好的定量了解大气CH 3Cl的源和汇将是非常宝贵的，以提高我们的预测能力平流层氯化学和臭氧层的稳定性。

项目成果

Chloromethane emissions in human breath.

• DOI: 10.1016/j.scitotenv.2017.06.202
• 发表时间: 2017-12
• 期刊: The Science of the total environment
• 作者: F. Keppler;J. Fischer;Tobias Sattler;D. Polag;Nicole Jaeger;H. Schöler;M. Greule

Chloromethane Degradation in Soils: A Combined Microbial and Two-Dimensional Stable Isotope Approach.

• DOI: 10.2134/jeq2017.09.0358
• 发表时间: 2018-03
• 期刊: Journal of environmental quality
• 影响因子: 2.4
• 作者: Nicole Jaeger;L. Besaury;E. Kröber;A. Delort;M. Greule;K. Lenhart;T. Nadalig;S. Vuilleumier;P. Amato;S. Kolb;F. Bringel;F. Keppler