BioFacts - Biomineral Factories: a platform for the discovery and engineering of biomineralization controls

生物矿物是生命塑造无机世界能力的迷人证明。通过矿物的形成，细菌参与了地球表面大多数元素的流动，对生物地球化学循环产生了深远的影响。生物矿物质的性质(例如，大小、形状、成分、结构)往往不同于化学沉淀的生物矿物质，而且从一个生物矿化有机体到另一个生物矿化生物。这些特性决定了生物矿物在环境中的反应性和生态功能。尽管对这一课题进行了大量的研究，但对控制“矿物表型”的生物学机制仍知之甚少。这一基本的知识差距正在拖延应用微生物生物矿化过程以可持续地生产工业用新材料的努力。在这里，我们将开发一个新的基于拉曼的平台，用于高通量分析微生物培养物中的生物矿物质(体内矿物学)。这个平台将允许我们一次筛选数百个微生物菌株，并表征它们的生物矿物产品的矿物学特性。我们将使用基于CRISPR的基因组编辑、下一代测序、比较基因组学、蛋白质组学和代谢组学相结合的方法，利用这个平台识别控制S氧化细菌产生的元素硫(S0)生物矿物质性质的关键遗传和生物分子系统。我们还将为微生物S0生物矿物的进化工程(定向进化)部署我们的筛选平台，这些矿物具有为不同技术应用量身定做的特性。这项研究带来的方法论突破将使我们对微生物生物矿化的生物控制的根本认识发生一步变化，并为未来利用细菌作为高价值材料的工业生物生产的“生物矿物工厂”铺平道路。

Biominerals are a fascinating testimony of life's capacity to shape the inorganic world. Through the formation of minerals, bacteria participate in fluxes of most elements at the surface of the Earth, having profound impacts on biogeochemical cycles. Biominerals often present properties (e.g., size, shape, composition, structure) that differ from those of their chemically precipitated counterparts, and from one biomineralizing organism to another. These specific properties determine the reactivity and ecological functions of biominerals in the environment. Despite intense research in this topic, there is still little understanding of the biological mechanisms controlling the "mineral phenotype". This fundamental knowledge gap is delaying efforts towards the application of microbial biomineralization processes for the sustainable production of novel materials for industry. Here we will develop a new Raman-based platform for the high-throughput analysis of biominerals in microbial cultures (in-vivo mineralogy). This platform will allow us to screen hundreds of microbial strains at a time and characterize the mineralogical properties of their biomineral products. Using an approach combining CRISPR-based genome editing, next-generation sequencing, comparative genomics, proteomics and metabolomics, we will use this platform to identify key genetic and biomolecular systems controlling the properties of elemental sulfur (S0) biominerals produced by a S-oxidizing bacterium. We will furthermore deploy our screening platform for the evolutionary engineering (directed evolution) of microbial S0 biominerals with tailored properties for diverse technological applications. The methodological breakthroughs enabled by this research will lead to a step change in our fundamental understanding of the biological controls of microbial biomineralization, and pave the way for the future use of bacteria as "biomineral factories" for the industrial bioproduction of high-value materials.