Genomic studies of biological soil crusts - successional dynamics for the rehabilitation of mine tailings facilities

摘要

Biological Soil Crusts (BSCs) are complex communities that include primary producers and multiple levels of consumers in the dependent food web generally consisting of hundreds of species. BSCs can increase porosity, enhance aggregate stability and improve physical structure of soils. Furthermore, BSCs protect soils from wind and water erosion, and they have been used in desertification control. Cyanobacteria are the principal live component of BSCs and provide most of the cohesive characteristics of the BSCs in arid and semi-arid lands by the production and secretion of polysaccharides that allow the chelation and bioavailability of nutrients for other organisms such as algae, fungi and other bacteria species. The microorganisms that are present in the BSCs are not easy to grow using traditional methods; hence, studies using molecular technigues can help to examine the wide range of microorganisms present in the communities. Due to the environmental features of the BSCs, it has been suggested that they can be used to bioremediate degraded soils for rehabilitation purposes. We conducted the first study carried out in Chile in order to develop a methodology for the use of biocrusts as the primary stabilisation means for both soil stockpiles and rehabilitated soil. The phylogenetic and diversity characterisation of BSCs through genomic analysis and bioinformatic tools will allow the development of a suitable methodology to culture and then to inoculate the communities of microorganisms on soils for mine site reclamation.