The geochemical ecology of cryptoendolithic microorganisms: relationships between cyanobacteria and sandstone weathering in the Canadian High Arctic

提供资金调查蓝藻和藻类在多大程度上参与了导致加拿大北极高地岩石快速风化和二氧化硅水泥和矿物溶解的高碱性条件的产生。初步结果表明，生物化学风化可能是一种大规模的机制，并提出了关于生化机制和微生物-矿物相互作用的新问题。拟议的项目将阐明光营养微生物在隐石器时代生境中由微生物介导的风化机制，以及这些微生物群落控制景观演变的程度。首席调查员将回答五个问题：1.蓝藻占主导地位的生境中微生物群落的性质是什么？2.蓝藻可以在多大程度上改变隐石器时代生境的孔隙水pH？3.蓝藻如何改变孔隙水的pH值，在什么表面条件下？4.碱性条件是否导致砂岩加速化学风化？5.溶解的二氧化硅的命运是什么？他将利用他在微生物学、分子生物学、地质学和地球化学研究中开发的野外和实验室工具和技术来表征隐石器时代的生境和相关微生物群落，确定蓝藻和藻类的生物碱化机制，并记录了光养微生物产生的高pH值对这一高北极环境中岩石风化的影响。

Funds are provided to investigate the degree to which cyanobacteria and algae are involved in generating hyperalkaline conditions that result in rapid rock weathering and dissolution of silica cements and minerals in the Canadian High Arctic. Preliminary results suggest a potentially large-scale mechanism for biogenic chemical weathering, and raise new questions about biochemical mechanisms and microbe-mineral interactions. The proposed project will elucidate microbially-mediated weathering mechanisms in cryptoendolithic habitats by phototrophic microorganisms, and the degree to which these microbial communities control landscape evolution. The Principal Investigator will address five questions: 1. What is the nature of the microbial community in cyanobacterial-dominated habitats?2. To what extent can cyanobacteria alter the pore water pH of cryptoendolithic habitats?3. How do cyanobacteria alter pore water pH, and under what surface conditions?4. Do alkaline conditions lead to accelerated chemical weathering of sandstone rocks?5. What is the fate of the dissolved silica?He will use both field and laboratory tools and techniques developed through his research in microbiology, molecular biology, geology and geochemistry to characterize the cryptoendolithic habitat and associated microbial communities, identify mechanisms for bioalkalization in cyanobacteria and algae, and document the impact of high pH generated by phototrophic microorganisms on rock weathering in this High Arctic environment.