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重要性的认识，土壤支持为人类提供基本服务，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来解开塑造土壤微生物群落结构的因素。这个研究部门的一个目标是通过让微生物参与到它们所支持的生态系统服务中来控制微生物。提出的研究计划的总体目标是识别和表征土壤细菌捕获分子氢（H2）和一氧化碳（CO）。这些微生物在所有陆地生态系统中无处不在，它们为人类提供了与全球相关的生态系统服务，因为它们负责大气H2和CO总损失的80%和15%。研究影响它们在环境中的分布和活动的因素尤为重要，因为这些细菌的缺失或失活将对地球气候产生巨大影响。我们的团队是世界上为数不多的研究微生物消耗大气H2和CO的专家之一，我们最近的工作表明，这些细菌在生物地球化学循环的调节中发挥了前所未有的作用，包括碳周转和土壤与空气之间的甲烷交换，从而导致温室效应。这些影响对于在土壤中产生大量H2和CO的豆科作物轮作序列的农业生态系统尤其重要。利用同位素示踪剂和宏基因组学等复杂的工具，我们将定义H2和CO如何将根分泌物中的碳重新分配给土壤微生物群落，以及它们给土壤带来的好处。由于加拿大是世界上最大的脉冲生产国之一，这项研究将使该国从他们的实践支持的生态系统服务中获益更多，包括温室气体的捕获和土壤生物多样性。这些努力将使加拿大能够为今世后代保持其在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.