Microbial geochemistry dynamics

在原始和污染的水环境中，细菌被广泛认为是一系列地球化学反应的主角。细菌作为地球化学反应“挑衅者”的行为不仅源于它们无处不在的分布和多样化的代谢能力，而且源于它们固有的细胞表面反应性和吸收各种溶解化学物质的能力。我们最近的大部分工作都是关于极端环境的（例如，安第斯山脉的温泉，加拿大北极高地），但并没有排除更“正常”的生态系统（例如，地下水泉），这些生态系统有助于定义这些极端。我们的研究还被用于量化微生物作为溶解矿物形成元素的吸附剂和矿物沉淀的成核底物的地球化学行为。迫切需要关注的是，探索产生细菌的矿物沉淀反应，以便在印度（致残疾病氟中毒流行的地方）对地下水供应的饮用水系统中的氟化物（F-）进行可持续的自然修复，以及评估深层地下和酸性矿井排水环境中原核病毒（即噬菌体）的多样性。以及它们通过吸附和矿物沉淀反应防止金属污染物在水系统中的迁移的潜力。研究还将侧重于开发涉及硅酸盐矿物的沉淀-溶解反应中微生物Fe2+/Fe3+氧化还原循环的动态定量地理空间模型，特别是在有助于从大气中去除二氧化碳的耦合过程方面。这一举措代表着微生物地球化学迈出了突破性的一步，进入了一个具有挑战性的新研究领域，重点是破译自然界中微生物和地球化学过程之间存在的复杂时空关系，并了解与环境变化相关的干扰即将产生的后果。

Bacteria are widely recognized as protagonists of a range of geochemical reactions in pristine and contaminated aqueous environments. The behavior of bacteria as geochemically reactive "agents provocateurs" is engendered not only by their ubiquitous distribution and diverse metabolic capabilities, but also stems from their intrinsic cell-surface reactivity and ability to sorb a wide range of dissolved chemicals. Much of our recent work has been on extreme environments (e.g., hot springs in the Andes, the Canadian High Arctic), but not to the exclusion of more "normal" ecosystems (e.g., groundwater springs) that help to define these extremes. Our studies have also been used to quantify the geochemical behavior of microorganisms as sorbents for dissolved mineral-forming elements, and as nucleation substrates for mineral precipitation. Of immediate concern is exploration of bacteriogenic mineral precipitation reactions for sustainable natural remediation of fluoride (F-) in groundwater-supplied drinking water systems in India (where the crippling disease fluorosis is endemic), as well as assessment of the diversity of prokaryotic viruses (i.e., bacteriophage) in the deep subsurface and acid mine drainage environments, and their potential to prevent metal contaminant migration in aqueous systems through sorption and mineral precipitation reactions. Studies will focus additionally on development of dynamic quantitative geospatial models for microbial Fe2+/Fe3+ redox cycling in precipitation-dissolution reactions involving silicate minerals, particularly in terms of coupled processes that contribute to the removal of CO2 from the atmosphere. This initiative represents a groundbreaking step forward for microbial geochemistry into a challenging new area of research focused on deciphering the complex spatial and temporal relationships that exist between microbial and geochemical processes in nature, and understanding impending consequences of disturbances associated with environmental change.