Microbial biotechnology as a tool to restore degraded drylands.

We briefly review how microbial biotechnology can contribute to improve activities aiming to restore degraded drylands and to combat their desertification, which are an integral part of the Sustainable Development Goal 15 of the 2030 Agenda. Microbial biotechnology offers notable promise to improve restoration actions based on the use of biocrust-forming engineered cyanobacteria, which play key roles in maintaining ecosystem structure and functioning in drylands worldwide. Advances in our understanding of microbiome associated to biocrusts and of the signalling involved in the communication among their constituents can also potentially enhance the outcome of restoration activities in drylands.