The Mineralosphere Concept: Mineralogical Control of the Distribution and Function of Mineral-associated Bacterial Communities

Soil is composed of a mosaic of different rocks and minerals, usually considered as an inert substrata for microbial colonization. However, recent findings suggest that minerals, in soils and elsewhere, favour the development of specific microbial communities according to their mineralogy, nutritive content, and weatherability. Based upon recent studies, we highlight how bacterial communities are distributed on the surface of, and in close proximity to, minerals. We also consider the potential role of the mineral-associated bacterial communities in mineral weathering and nutrient cycling in soils, with a specific focus on nutrient-poor and acidic forest ecosystems. We propose to define this microbial habitat as the mineralosphere, where key drivers of the microbial communities are the physicochemical properties of the minerals.

TrendsRocks and minerals vary in their chemical composition, weatherability, and distribution.Rocks and minerals support the development of life and especially of complex bacterial communities, capable of weathering minerals.Is colonization of rocks and minerals by bacteria a random or a controlled process?Several studies suggest that physicochemical properties of minerals and rocks determine mineral colonization by bacteria, supporting the definition of the mineralosphere concept.Parallels can be made between the rhizosphere effect on bacterial communities and the mineralosphere effect proposed here.