Life on the Rocks: Chronic Subaerial Microbial Biofilms on Stone Monuments

微生物，或者更准确地说，微生物群落，因其代谢多样性而引人注目，远远超过多细胞生物。哪里有自由能源和生命必需元素的来源，哪里就有可能发现微生物群落，而不管可能存在的任何环境压力。这样的环境群落对所有地球化学循环和地球上的所有生命都是必不可少的。由于它们能够有效地回收几乎所有来自多细胞生物的天然聚合物和其他产物，它们对多细胞生命的功能也直接至关重要。该项目将侧重于开发在空气暴露的石头环境中模拟微生物群落的方法。目标是根据对其严酷的物理和化学环境的了解，以及通过基因组技术对其代谢能力的了解，描述这些群落的形式和功能及其代谢活动。我们将从阿灵顿国家公墓和Cimitero纪念碑（意大利米兰）的大理石表面上收集微生物群落的数据，并将结果数据纳入基于物理的数学模型中。地面上的石头表面通常对生命不利，其结果是任何微生物群落的代谢可能相对简单（例如，与肠道微生物代谢相比），并且可能相当孤立，因为其他生物很难生存。另一方面，这种非常脆弱可能意味着群落与其物理环境紧密协调，因此了解它们彼此之间以及与环境的相互作用对于理解群落功能是必要的。在社区中，团体关系可能对生存很重要。所有这些都使它们成为建模研究的可能对象。项目团队将结合现场（阿灵顿国家公墓圆形剧场）的24小时研究和物理生物膜模型来定性地表征这样一个系统。长期的、多物种的环境微生物群落及其与周围环境的相互作用的详细建模和表征尚未进行。这是一项重要的任务，因为它的物理、化学和生物方面是非平凡的和强耦合的。这个项目的核心是在一个范例自然社区中解决这些问题。PI的目标是将综合数据收集结合并集成到一个多尺度模型中，该模型提供了环境微生物群落的定量特征。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Microbes, and maybe more correctly, microbial communities, are remarkable for their metabolic diversity, far exceeding that of multicellular organisms. Where there is a source of free energy and essential elements for life, there is likely a microbial community to be found, regardless of any environmental stresses that might be present. Such environmental communities are essential to all geochemical cycles and hence to all life on earth. They are also directly essential to function of multicellular life due to their ability to effectively recycle almost all natural polymers and other products from multicellular organisms. This project will focus on the development of methods for modeling microbial communities within the context of air-exposed stone environments. The goal is to characterize the form and function of such communities and their metabolic activity based on knowledge of their stark physical and chemical environments, and of their metabolic capability through genomic techniques. We will gather data from microbial communities growing on marble surfaces at Arlington National Cemetery and Cimitero Monumentale (Milan, Italy), and incorporate the resulting data into physics-based mathematical models.Subaerial stone surfaces are generally hostile platforms for life with the consequence that any microbial community metabolism is likely relatively simple (as compared, for example, to a gut microbial metabolism), and is likely fairly isolated, as it is difficult for other organisms to survive. On the other hand, this very tenuousness likely means that the community is tightly tuned to its physical environment, so that understanding their interactions with each other and with their environment is necessary for understanding community function. Within the community, consortial associations are probably important for survival. All of these things make them likely candidates for modeling study. The project team will combine 24 hour study of a field site (the Arlington National Cemetery amphitheater) with a physical biofilm model to qualitatively characterize such a system. Detailed modeling and characterization of a chronic, multispecies environmental microbial community, and its interaction with its surroundings, has not been carried out. This is a significant task because of its non-trivial and strongly coupled physical, chemical, and biological aspects. The core of this project is to address these issues in an example natural community. The PI's aim is to combine and integrate comprehensive data gathering into a multiscale model that provides a quantitative characterization of an environmental microbial community.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.