Microbial processes supported by hydrogen and carbon monoxide produced in soil

联合国组织宣布2015年为国际土壤年，以提高人们对保护土壤的重要性的认识，这些土壤支持对人类的基本服务，包括粮食安全和减少温室气体排放。这些挑战直接符合现代微生物学家的使命，他们受益于极其强大的技术工具，以理清影响土壤微生物群落结构的因素。这个研究部门的一个雄心是通过让微生物参与它们所支持的生态系统服务来控制它们。拟议研究计划的首要目标是识别和表征能够捕获分子氢(H2)和一氧化碳(CO)的土壤细菌。这些微生物普遍存在于所有陆地生态系统中，它们为人类提供与全球相关的生态系统服务，因为它们分别占大气H2和CO总损失的80%和15%。审查影响它们在环境中的分布和活动的因素特别重要，因为这些细菌的不存在或失活将对地球气候产生重大影响。我们的团队是世界上为数不多的研究消耗大气中H2和CO的微生物的专家之一，我们最近的工作表明，这些细菌在调节生物地球化学循环中发挥了以前没有被怀疑的作用，包括碳周转和甲烷的土壤-空气交换，从而导致温室效应。这些影响在作物与豆类轮作的农业生态系统中尤其重要，这些轮作会在土壤中产生大量的H2和CO。利用同位素示踪和元基因组学等先进工具，我们将确定H2和CO如何将根分泌物中的碳重新分配到土壤微生物群落中，以及它们给土壤带来的好处。由于加拿大是世界上最大的豆类生产国之一，这项研究将使该国从其实践支持的生态系统服务中获得更多好处，包括捕获温室气体和土壤生物多样性。这些努力将使加拿大能够保持其在今世后代可持续粮食生产方面的领导地位。

The United Nations Organization declared 2015 the International Soil Year to raise awareness of the importance of protecting soils that support essential services to humankind, including food security and mitigation of greenhouse gases emissions. These challenges are directly in line with the mission of modern microbiologists who benefit from extremely powerful technological tools to disentangle factors shaping the structure of soil microbial communities. One ambition of this research sector is to take control of microorganisms by engaging them into the ecosystem services they support. The overarching objective of the proposed research program is to identify and characterize soil bacteria that capture molecular hydrogen (H2) and carbon monoxide (CO). These microorganisms, which are ubiquitously found in all terrestrial ecosystems, support globally-relevant ecosystem services to humanity since they are responsible for 80% and 15% of the total losses of atmospheric H2 and CO. Examination of the factors influencing their distribution and activity in the environment is of particular importance since the absence or inactivation of these bacteria would have dramatic consequences on the climate on Earth. Our team is among the few experts worldwide studying microorganisms consuming atmospheric H2 and CO and our recent work suggests that these bacteria play a previously unsuspected role in the modulation of biogeochemical cycles, including carbon turnover and soil-to-air exchanges of methane contributing to greenhouse effect. These effects would be particularly important in agroecosystems with sequences of crop rotation with legumes that produce enormous amounts of H2 and CO in soil. Using sophisticated tools such as isotopic tracers and metagenomics, we will define how H2 and CO reallocate carbon from root exudates to soil microbial communities and the benefits they bring to the soil. As Canada is one of the world's largest pulse producers, this research will allow the country to benefit more from the ecosystem services their practices support, including the capture of greenhouse gases and soil biodiversity. These efforts will enable Canada to maintain its leadership in sustainable food production for present and future generations.