Environmental controls on microbialite and microbial mat biomineralization in Saskatchewan

矿物生物签名和微生物群落：矿物生物签名是指具有独特结构的沉积物或岩石，这些结构是由活的有机体产生的。当在岩石记录中发现时，矿物生物特征提供了历史上微生物生命的记录；例如，生锈矿物的螺旋线是富含铁的水中细菌活动的证据。地质学家利用这些信息来帮助理解地球上古代环境和生命的历史。萨斯喀彻温省的草原景观拥有一系列独特的环境，微生物在这里产生矿物生物特征，包括矿泉和沼泽中的铁和硫微生物垫。在草原盐湖中，微生物可以加速生物矿物的形成，并在微生物岩(层状丘状结构)中堆积。这些生物系统在萨斯喀彻温省的大陆性气候中经历了戏剧性的季节性极端温度和干旱。伴随着全球气候变化而变化的气候条件造成了额外的压力，这些变化对矿物生物特征的影响尚未被记录在案。目的：本研究计划的目的是确定气候参数变化(如温度、盐度)如何影响微生物岩和微生物垫中的微生物群落，以及这如何影响矿物生物特征的形成、蚀变、形态和地球化学。科学方法：这项研究将整合一套多学科的实地和实验室研究方法。我们将使用分子微生物学技术来研究我们现场的多样性、分布和季节微生物变化，并对这些环境中的微生物进行培养和表征。将使用光学和电子显微镜以及基于同步加速器的分析工具来检查生物特征的矿物结构、形态和化学。基于实验室的模型系统将模拟这些生物签名形成的环境，并测试变化的条件对生物签名形成的影响。影响：研究萨斯喀彻温省现代生物标志性环境的地质微生物学将产生原创性研究，对理解全球和地质历史中这些系统中的微生物-矿物相互作用以及工业相关应用具有重要意义。这项研究将阐明季节变化、气候变化和矿物生物特征形成和改变之间的关系，这将提高我们在岩石记录和火星等外星环境中识别和解释生物特征的能力。我们分离的微生物将具有作为研究和水处理应用(例如，从地下水中去除铁或硫)的模式生物的价值。更广泛的科学影响包括对气候参数变化如何影响其他环境中类似的微生物-矿物相互作用的新见解(例如，在钢铁基础设施的腐蚀、矿山废物以及沉积物和土壤中)。

Mineral biosignatures and microbial communities: Mineral biosignatures are sediments or rocks with structures uniquely produced by living organisms. When identified in the rock record, mineral biosignatures provide a record of historical microbial life; for example, helical threads of rusty minerals are evidence of bacterial activity in iron-rich waters. Geologists use this information to help understand the history of ancient environments and life on Earth. Saskatchewan's prairie landscape hosts a range of unique environments where microbes produce mineral biosignatures, including iron and sulfur microbial mats in mineral springs and marshes. In prairie saline lakes, microbes can accelerate biomineral formation and accumulate in microbialites (layered mound structures). These biological systems experience dramatic seasonal extremes of temperature and aridity in Saskatchewan's continental climate. Changing climate conditions concomitant with global climate change contribute additional stresses and affects of these changes on mineral biosignatures has not yet been documented. Objective: The objective of this research program is to determine how changing climate parameters (e.g., temperature, salinity) affect microbial communities in microbialites and microbial mats, and how this influences mineral biosignature formation, alteration, morphology, and geochemistry. Scientific approach: This research will integrate a multidisciplinary suite of field and laboratory research methods. We will use molecular microbiological techniques to study diversity, distribution, and seasonal microbiological variations at our field sites and microbes from these environments will be cultured and characterized. Light and electron microscopy and synchrotron-based analytical tools will be used to examine the mineral structures, morphology, and chemistry of the biosignatures. Lab-based model systems will simulate environments where these biosignatures form and test the influence of changing conditions on biosignature formation. Impact: Examining the geomicrobiology of modern biosignature environments in Saskatchewan will produce original research with implications for understanding microbe-mineral interactions in these systems globally and in geological history, as well as in industry-relevant applications. This research will illuminate relationships between seasonal changes, climate change, and mineral biosignature formation and alteration that will improve our ability to recognize and interpret biosignatures in the rock record, and in extraterrestrial environments such as Mars. The microbes we isolate will have value as model organisms for research, and in water treatment applications (e.g., removal of iron or sulfur from groundwater). Broader scientific impacts include new insight on how changing climate parameters influence similar microbe-mineral interactions in other settings (e.g., in corrosion of steel infrastructure, in mine wastes, and in sediments and soils).