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

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.