Identifying novel microbial drivers to mitigate atmospheric methane emission

气候变化是我们世界面临的最大挑战之一。甲烷是一种强大的温室气体，其全球变暖潜力是二氧化碳的25倍。在最近举行的2021年气候变化峰会COP26上，国际社会承诺到2030年将甲烷排放量紧急削减30%。该项目将研究能够消耗甲烷的新微生物，并产生为实现这一目标迈出第一步所需的基本科学知识。每年约有5-6亿吨甲烷排放到地球大气中。甲烷可以被称为甲烷氧化菌的微生物去除。然而，我们有初步数据表明，其他以前未被怀疑的微生物，如氨氧化古生菌，也可能能够消耗环境中的甲烷。氨氧化古生菌是地球上数量最多的生物之一，在氮循环中发挥着至关重要的作用。它们对农业土壤的氮素流失、环境污染和含氮气候活性气体的排放负有责任。氨氧化古生菌和甲烷氧化菌都含有一种类似的酶，在古生菌中被称为氨单加氧酶，在甲烷氧化菌中被称为颗粒甲烷单加氧酶。这是甲烷氧化菌用来分解甲烷的关键酶。我们的假设是，古生菌可以使用它们的氨单加氧酶来分解环境中的甲烷。此外，我们预测甲烷将抑制氨氧化，从而影响环境中的氮循环。这一点很重要，因为根据环境条件的不同，不同的微生物会比其他微生物更活跃，这会对温室气体排放和消耗的程度以及养分的循环产生影响。我们的研究将确定不同的环境条件如何影响参与从生物圈中去除甲烷的不同微生物组的贡献。利用尖端技术，该项目将把土壤中甲烷消耗的微生物的活动和身份联系起来。我们的研究将确定氨氧化古生菌和其他微生物分解土壤中甲烷的机制。总体而言，这将有助于预测土壤对环境变化的反应，并具有相当大的潜力，有助于土壤生态系统的可持续管理。

Climate change is one of the greatest challenges facing our world. Methane is a powerful greenhouse gas with a global warming potential 25 times that of CO2. In the recent Climate Change Summit COP26 in 2021, an international pledge was made to urgently cut methane emissions by 30% by 2030. This project will study new microbes capable of consuming methane and generate fundamental scientific knowledge required to take the first steps towards contributing to this goal.Approximately 500-600 million tonnes of methane are emitted into the Earth's atmosphere every year. Methane can be removed by microbes known as methanotrophs. However, we have preliminary data indicating that other, previously unsuspected microbes known as ammonia oxidising archaea may also be able to consume methane in the environment. Ammonia oxidising archaea are among the most numerous living organisms on the planet and play a vital role in the nitrogen cycle. They are responsible for nitrogen loss from agricultural soils, environmental pollution and emission of nitrogen-containing climate-active gases. Ammonia oxidising archaea and methanotrophs both contain a similar enzyme, known as ammonia monooxygenase in archaea and particulate methane monooxygenase in methanotrophs. This is the key enzyme that methanotrophs use to break down methane. Our hypothesis is that archaea can use their ammonia monooxygenase enzyme to break down methane in the environment. Furthermore, we predict that methane will inhibit ammonia oxidation and thus influence nitrogen cycling in the environment. This is important because depending on the environmental conditions, different microbes will be more active than others and this has consequences for the extent of greenhouse gas emission and consumption, and cycling of nutrients. Our research will identify how different environmental conditions affect the contributions of different groups of microorganisms involved in methane removal from the biosphere. Using cutting-edge techniques, this project will link the activity and identity of the microbes responsible for methane consumption in soil. Our study will determine the mechanisms by which ammonia oxidising archaea and other microbes break down methane in soil. Overall, this will help towards predicting how soils respond to environmental changes and has considerable potential to contribute to sustainable management of soil ecosystems.