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

政府间气候变化专门委员会2014年的报告高度自信地指出，“从1970年到2010年，人为温室气体排放总量继续增加，在接近这一时期结束时，绝对十年增长幅度更大”。一种被提议的减缓气候变化的方法是将二氧化碳(CO2)隔离在超镁铁质地下。然而，人们对超镁铁质次表层的生物地球化学碳循环特征和深层生物圈特征知之甚少。例如，这种二氧化碳储存方法可能会产生甲烷(CH4)，这是另一种强大的温室气体。在追踪这个超镁铁质系统中的碳基质、转化和产物方面，需要进行纯粹的研究。我正在进行的研究计划为这一需求做出了贡献，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处理；2)通过连接深层生物圈和大气的门户确定碳源和碳通量。需要资金来研究与蛇纹岩作用相关的高pH(&gt；11)地下水中的微生物过程--蛇纹岩作用是水和超镁铁质岩石之间的一系列反应。我的第一组研究问题是问这些微生物吃什么，它们产生什么，以及它们如何在超镁铁质地下生存。我的第二组研究问题是，这些系统如何与大气交换碳，以及这些系统释放出的CH4的形成机制是什么。加拿大将通过这项研究产生10名高素质的人员--2名博士、3名硕士和5名本科生论文。加拿大人还将受益于碳基质、微生物转化和与表面的无机和有机碳交换方面的知识进步，以及关于生命如何在高pH(&gt；11)环境中生存和繁衍的新生物学发现。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，蛇单胞菌利用碳酸盐岩作为碳源，这是一种最近被发现适应蛇纹岩地下水高pH值的微生物。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，因为这种有机体可以将碳从长期碳循环转移到短期碳循环。必须考虑量化强大的温室气体CH4和CO2进出大气层和深层生物圈之间的入口的通量，特别是考虑到深层生物圈可能容纳了地球上的大部分生物量，如果在这些系统中部署了二氧化碳封存。

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.