Diversity and Ecophysiology of High Affinity H2-Oxidizing Bacteria Scavenging Atmospheric H2

清除大气 H2 的高亲和力 H2 氧化细菌的多样性和生态生理学

• 批准号: 418252-2012
• 负责人: Constant, Philippe
• 金额: $ 2.4万
• 依托单位: Institut national de la recherche scientifique
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=573559
• 关键词: Diversity; Ecophysiology; Affinity; H2; Oxidizing

Molecular hydrogen (H2) is an indirect greenhouse gas regulating the abundance of hydroxyl radicals, the cleansing molecules removing methane from the atmosphere. About 80% of total H2 emissions are currently mitigated by the biological soil uptake of atmospheric H2, thus explaining the stability of its global atmospheric burden over the last decades. H2-based economy modeling scenarios raised concerns about a potential increase of atmospheric H2 levels, altering the oxidative capacity of the atmosphere and enhancing atmospheric methane lifetime. This rise was attributed to inevitable losses during H2 production, transport and storage and, the inability of the soil uptake of atmospheric H2 to compensate for these additional emissions. These projections have caused some controversy because future trends in fuel technologies and H2 emissions are very difficult to predict and moreover, the question whether the soil sink of atmospheric H2 is vulnerable to climate evolution and other anthropogenic disturbances remains unresolved. The overall objective of this research program is to define «how» the environment is shaping the diversity, distribution and activity of H2-oxidizing bacteria possessing a novel high affinity [NiFe]-hydrogenase responsible for the soil uptake of atmospheric H2. This challenge will be addressed by a unique combination of microbiological and molecular analyses and the monitoring of H2 turnover of bacterial cultures and soil. We will elucidate the physiological role of high affinity H2ase, the diversity of high affinity H2 oxidizing-bacteria and reveal the environmental control of their distribution and activity. Localizing and quantifying active H2-oxidizing bacteria in soil and relating their distribution and activity to environmental variables and biogeochemical networks is essential to recognize ecosystems for which the ability to consume atmospheric H2 is susceptible to global change and land-management practices - thus favouring the implementation of strategies to ensure a continued stability of the current mass balance of atmospheric H2 in Canada and worldwide.

分子氢（H2）是一种间接的温室气体，可节省大量的羟基自由基，清洁分子从大气中去除甲烷。目前，大气H2的生物土壤吸收目前，大约80％的H2排放量减轻了，从而解释了过去几十年中其全球大气燃烧的稳定性。基于H2的经济建模方案引起了人们对大气H2水平潜在增加的担忧，从而改变了大气的氧化能力并增强了大气中的甲烷寿命。这一上升归因于H2生产，运输和存储期间不可避免的损失，以及土壤吸收大气H2无法补偿这些额外的排放。这些项目引起了一些争议，因为燃料技术和H2排放的未来趋势很难预测，此外，大气中H2的土壤沉水量是否容易受到气候进化的影响，而其他人为疾病仍未得到解决。该研究计划的总体目的是定义“如何”环境塑造具有新型高亲和力[Nife] - 氢化酶的多样性，分布和活性，负责大气摄取H2的土壤。这项挑战将通过微生物和分子分析以及对细菌培养物和土壤的H2更新的独特组合来解决这一挑战。我们将阐明高亲和力H2ase的身体作用，高亲和力H2氧化 - 细菌的多样性，并揭示其分布和活性的环境控制。 Localizing and quantifying active H2-oxidizing bacteria in soil and relating their distribution and activity to environmental variables and biogeochemical networks is essential to recognize ecosystems for which the ability to consume atmospheric H2 is susceptible to global change and land-management practices - thus favouring the implementation of strategies to ensure a continued stability of the current mass balance of atmospheric H2 in Canada and worldwide.