Investigating microbial carbon transformations in the ultramafic biosphere and carbon fluxes through serpentine spring portals

研究超镁铁质生物圈中的微生物碳转化和通过蛇纹泉入口的碳通量

• 批准号: RGPIN-2015-06047
• 负责人: Morrill, Penny
• 金额: $ 1.97万
• 依托单位: Memorial University of Newfoundland
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=660271
• 关键词: Investigating; microbial; carbon; transformations; ultramafic

The 2014 IPCC report states with high confidence that "Total anthropogenic GHG emissions have continued to increase over 1970 to 2010 with larger absolute decadal increases toward the end of this period". One proposed method of climate change mitigation is to sequester the carbon dioxide (CO2) in the ultramafic subsurface. However, the biogeochemical carbon cycling and the deep biosphere in the ultramafic subsurface are poorly understood. For example, this CO2 storage method may result in the production of methane (CH4) another powerful greenhouse gas. Pure research in tracing the carbon substrates, transformations, and products in this ultramafic system is required. My ongoing research program contributes to this need with long-term goals of 1) determining biogeochemical processing of carbon in the deep ultramafic biosphere and 2) determining carbon source and flux through portals that connect the deep biosphere and the atmosphere. Funds are requested to study the microbial processes in the high pH (>11) groundwaters associated with serpentinization - a set of reactions between water and ultramafic rock. My 1st set of research questions ask what do the microbes eat, what do they produce, and how do they survive in the ultramafic subsurface. My 2nd set of research questions ask, how do these systems exchange carbon with the atmosphere and what are the mechanisms that form the CH4 that is released from these systems. Canada will benefit from this research through the production of 10 highly qualified personnel - 2 PhD, 3 MSc, and 5 Undergraduate theses. Canadians will also benefit from the advancement in knowledge into carbon substrates, microbial transformations, and inorganic and organic carbon exchanges with the surface, as well as new biological discoveries in how life survives and thrives in high pH (>11) environments. These results could have a huge impact on how we view carbon transformations between short-term and long-term carbon cycles. For example, the use of carbonate rock as a carbon source by Serpentinomonas, a microbe recently discovered to be adapted to the high pH of serpentinized groundwater. This carbon transformation could have large implications on our understanding of the global carbon cycle, because this organism can move carbon out of the long-term carbon cycle to the short-term carbon cycle. Quantifying the flux of powerful greenhouse gases, CH4 and CO2, in and out of portals between the atmosphere and the deep biosphere must be considered, especially since the deep biosphere may house the majority of biomass on the planet and if CO2 sequestration is deployed in these systems.

IPCC 2014年的报告非常有信心地指出，“1970年至2010年期间，人为温室气体排放总量持续增加，在这一时期末期，绝对年代际增长幅度更大”。减缓气候变化的一种建议方法是将二氧化碳（CO2）隔离在超镁基地下。然而，超镁铁质地下的生物地球化学碳循环和深层生物圈的研究却很少。例如，这种二氧化碳储存方法可能会产生另一种强大的温室气体甲烷（CH4）。在追踪碳底物，转化和产品在这个超镁铁系统的纯研究是必需的。我正在进行的研究项目有助于满足这一需求，其长期目标是：1)确定深层超镁铁质生物圈中碳的生物地球化学过程；2)确定通过连接深层生物圈和大气的入口的碳源和通量。要求资金用于研究高pH值地下水中与蛇纹石化有关的微生物过程，蛇纹石化是水和超镁质岩石之间的一系列反应。我的第一个研究问题是微生物吃什么，它们生产什么，以及它们如何在超镁质地下生存。我的第二组研究问题是，这些系统如何与大气交换碳以及从这些系统释放的CH4形成的机制是什么。加拿大将从这项研究中受益，通过生产10名高素质人才- 2名博士，3名硕士和5篇本科论文。加拿大人还将受益于对碳基质、微生物转化、无机和有机碳与地表交换的知识的进步，以及关于生命如何在高pH （bbb11）环境中生存和繁荣的生物学新发现。这些结果可能会对我们如何看待短期和长期碳循环之间的碳转化产生巨大影响。例如，蛇形单胞菌利用碳酸盐岩作为碳源，这种微生物最近被发现能够适应蛇形化地下水的高pH值。这种碳转化可能会对我们对全球碳循环的理解产生重大影响，因为这种生物可以将碳从长期碳循环转移到短期碳循环。必须考虑对强效温室气体CH4和CO2进出大气层和深层生物圈之间门户的通量进行量化，特别是因为深层生物圈可能容纳了地球上的大部分生物量，而且如果在这些系统中部署了二氧化碳封存技术。