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.

作为大气甲烷最大的天然来源，泥炭地储存了超过30%的陆地碳(Rodhe, 1990; Gorham, 1991; Hein et al., 1997)，大部分碳来自泥炭藓和互利共生的甲烷氧化菌群落(图 1）（Clymo 和 Hayward，1982 年，Raghoebarsing 等人。 2005年；）。然而，由于人类活动和气候变暖，全球超过15%的泥炭地已被破坏。尤其是在英国，只有不到 20% 的泥炭地得以幸存（Bain 等，2011）。英国提出了旨在重新湿润泥炭地并在受损地区重新种植泥炭藓的恢复项目。先前的研究表明，当使用 Beadamoss 可持续种植的泥炭藓 (BeadaHumok) 来恢复天然泥炭地时，泥炭地的甲烷排放量会显着减少 (Keightley, 2020)，但尚未证明甲烷氧化细菌是否与微繁殖泥炭藓有关。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可以直接主动降解来自温室的甲烷，并且与天然泥炭地中生长的泥炭藓相比，它表现出类似的降解甲烷的能力。我鉴定了一些相关的甲烷氧化菌，它们主要是甲基囊菌属、甲基红窦菌属、甲基囊菌属和甲基细胞菌属。该项目的总体目标是表征泥炭地恢复过程中与可持续生长的泥炭藓相关的甲烷氧化菌的结构和生态生理学，重点是温室种植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：使用依赖于（分离）和不依赖于栽培的方法（功能遗传标记和元组学方法）在温室中通过微繁殖可持续生长的不同泥炭藓的甲烷氧化潜力并确定相关甲烷氧化菌研究生态生理学与泥炭藓相关的甲烷氧化菌评估其利用非甲烷底物的能力（兼性甲烷氧化菌）研究甲烷氧化菌和苔藓（甲烷氧化菌降解甲烷的能力；泥炭藓的光合能力）。开发“质量控制”程序，以确定在恢复项目中使用苔藓之前甲烷氧化菌的存在和活性。评估与苔藓相关的甲烷氧化菌是否保留在在恢复项目中建立泥炭藓后的沼泽。我们将设计一个泥炭地中生态系统来模拟水苔的自然生长环境泥炭藓（由 Kox 等人撰写） (2021) 并通过气相色谱法测量甲烷的降解率。将使用针对 DNA、RNA 和蛋白质的分子方法（包括定量 PCR 和宏基因组/宏转录组/宏蛋白质组）来确定泥炭藓相关甲烷氧化菌的多样性和活性。稳定同位素与 13C 标记底物的孵育将用于确定存在的潜在兼性甲烷氧化菌的底物范围。还将进行甲烷氧化菌的分离。我们将利用通量测序开发检测泥炭藓中甲烷氧化菌定植和分布的方法，并将其应用于泥炭藓移植前后的泥炭地恢复项目。