Marine saltems are saline environments that are used for the commercial production of salt by the evaporation of seawater.They are excellent models for the study of the microbial ecology and relationship of halophilic microorganisms that live under a wide range of saline conditions,from seawater to salt saturation.One of the salterns that have been extensively used for microbiological studies during the last 35 years is located in Santa Pola,near Alicante(East Spain).We have accumulated studies using the different methodologies,from the classical culture-dependent to culture-independent techniques(Ventosa et al.,2014).Recently we carried out metagenomic studies in several ponds of the saltern with salinities of 13%,19%,33%and 37%total salts,as well as a pond with 21%salts of another saltem located in Isla Cristina(South-West Spain).The detailed bioinformatic analyses of these five metagenomes permitted to determine in detail the prokaryotic phylogenomic and metabolic diversity of these hypersaline habitats and lately to design new approaches in order to isolate in pure culture the most abundant archaea and bacteria present on these habitats.These metagenomic studies have confirmed the abundance of Haloquadratum,the extremely halophiic bacterium Salinibacter and the non-yet isolated nanohaloarchaea in the most hypersaline ponds of the salterns,and determined that in intermediate salinity ponds there is a wider diversity,with an abundant group of members of the Gammaproteobacteria,closely related to the genus Alkalilimnicola.Several new haloarchaea,specially new species belonging to the genus Halorubrum have been recently isolated and especially relevant is the isolation of a new bacterium representative of the aforementioned abundant group of Gammaproteobacteria,that has been characterized and described as a new genus and species,Spiribacter salinus(León et al.,2014).The sequencing of the complete genome has permitted to complete the characterization of this new organism and to determine its abundance and role in hypersaline habitats.Besides,recent metagenomic studies on saline soils have complemented the studies on salterns.