Mitigation of Methane Emissions from Peatlands - a Role for Micro-propagated Sphagnum-Associated Methanotrophs

减少泥炭地的甲烷排放——微繁殖泥炭藓相关甲烷氧化菌的作用

• 批准号: 2881372
• 金额: --
• 依托单位: University of Warwick
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2881372
• 关键词: Mitigation; Methane; Emissions; Peatlands; Role

As the largest natural source of atmospheric methane, peatlands store over 30% of terrestrial carbon (Rodhe, 1990; Gorham, 1991; Hein et al., 1997), most of the carbon comes from Sphagnum mosses and mutually beneficial symbiotic methanotrophic bacteria community (Figure 1) (Clymo and Hayward, 1982, Raghoebarsing et al. 2005;). However, more than 15% of peatlands have been destroyed globally due to human activities and climate warming. Especially in the UK, less than 20% of peatlands survived (Bain et al., 2011). Restoration projects aiming to rewet peatland and replant Sphagnum moss in damaged areas was presented in the UK. Prior research has shown that methane emissions from peatlands are significantly reduced when Beadamoss sustainably grown Sphagnum moss (BeadaHumok) is used to restore natural peatlands (Keightley, 2020), however, it has not been shown whether methanotrophic bacteria are associated with micropropagated Sphagnum. In my MSc dissertation project, I demonstrated that BeadaHumok actively degrades methane straight from the greenhouse even before adaptive evolution in natural peatland and showed similar ability to degrade methane compared to Sphagnum mosses grown in natural peatland. I identified some of the associated methanotrophic bacteria, they were dominated by the genera Methylocystis, Methylosinus, Methylocapsa and Methylocella.The overall aim of the project is to characterise the structure and ecophysiology of methanotrophs associated with sustainably grown Sphagnum moss during peatland restoration, with emphasis on the maintenance of methanotrophs in the greenhouse growing system, and changes in methanotroph populations before and after restoration. The project has the following objectives:Determine methane oxidation potential and identify associated methanotrophs of different Sphagnum mosses grown sustainably by micropropagation in the greenhouse using cultivation-dependent (isolation) and -independent approaches (functional genetic markers and meta-omics approaches)Study the ecophysiology of Sphagnum-associated methanotrophs to evaluate their capability for using non-methane substrates (facultative methanotrophy)Investigate the interaction of methanotrophs and mosses (ability of methanotrophs to degrade methane; photosynthetic capacity of Sphagnum mosses).Development of a 'quality control' procedure to determine presence and activity of methanotrophs prior to use of mosses in restoration projects.Assess whether moss-associated methanotrophs are maintained in the bogs post establishment of Sphagnum moss in restoration projects.We will design a peatland mesocosm for simulating the natural growth environment of Sphagnum moss (as by Kox et al. (2021) and measure the rate of degradation of methane by gas chromatography.The diversity and activity of Sphagnum associated methanotrophs will be determined using molecular methods targeting DNA, RNA and protein, including quantitative PCR, and metagenomic/metatranscriptomics/metaproteomics. Stable isotope incubations with 13C labelled substrates will be used to determine the substrate range of potentially facultative methanotrophs present. Isolation of methanotrophs will also be carried out.We will use throughput sequencing to develop methods to detect the colonisation and distribution of methanotrophs in Sphagnum moss and apply these to peatland restoration projects before and after transplantation of Sphagnum mosses.

作为大气甲烷的最大天然来源，泥炭地储存超过30%的陆地碳（Rodhe，1990;戈勒姆，1991; Hein等人，1997），大部分碳来自泥炭藓和互利共生的甲烷氧化细菌群落（图1）（Clymo和海沃德，1982，Raghoebarsing等人，2005;）。然而，由于人类活动和气候变暖，全球超过15%的泥炭地被破坏。特别是在英国，只有不到20%的泥炭地存活下来（Bain等人，2011年）。联合王国介绍了旨在使泥炭地重新湿润和在受损地区重新种植泥炭藓的恢复项目。先前的研究表明，当Beadamoss可持续生长的泥炭藓（BeadaHumok）用于恢复天然泥炭地时，泥炭地的甲烷排放量显着减少（Keightley，2020），然而，尚未显示甲烷营养细菌是否与微繁殖的泥炭藓有关。在我的硕士论文项目中，我证明了BeadaHumok甚至在天然泥炭地的适应性进化之前就直接从温室中积极降解甲烷，并且与天然泥炭地中生长的泥炭藓相比，表现出类似的降解甲烷的能力。本项目的总体目标是研究泥炭地恢复过程中与泥炭藓可持续生长相关的甲烷氧化菌的结构和生理生态，重点是温室生长系统中甲烷氧化菌的维持，以及恢复前后甲烷氧化菌种群的变化。该项目有以下目标：确定甲烷氧化潜力，并确定相关的甲烷氧化菌的不同泥炭藓藓可持续发展的微体繁殖在温室中使用的培养依赖（隔离）和独立方法（功能遗传标记和元组学方法）研究泥炭藓相关甲烷氧化菌的生理生态学，以评估其利用非甲烷底物的能力（兼性甲烷氧化）研究甲烷氧化菌和苔藓的相互作用（甲烷氧化菌降解甲烷的能力;泥炭藓的光合能力）制定“质量控制”程序，在恢复项目中使用苔藓之前确定甲烷氧化菌的存在和活动。在泥炭藓建立后的恢复工程中，泥炭藓相关甲烷氧化菌是否在沼泽中维持。我们将设计一个泥炭地围隔生态系统来模拟泥炭藓的自然生长环境（如Kox等人（2021）所述），并通过气相色谱法测量甲烷降解速率。泥炭藓相关甲烷氧化菌的多样性和活性将使用靶向DNA的分子方法来确定，RNA和蛋白质，包括定量PCR和宏基因组学/元转录组学/元蛋白质组学。将使用13 C标记底物的稳定同位素孵育来确定存在的潜在兼性甲烷氧化菌的底物范围。我们亦会进行甲烷氧化菌的分离，并会利用通量测序技术，发展检测甲烷氧化菌在泥炭藓中的定殖和分布的方法，并将这些方法应用于泥炭藓移植前后的泥炭地恢复项目。