Sediment cores (the top 5 cm), composed mainly of salt crystals and brine, were sampled in June 2016 from the final crystallizer pond Vasca #27 of the solar saltern system Saline della Laguna (Sicily, Italy). Chemical analysis of environmental samples, cultivation conditions, microbial community analysis, genome sequencing and assembly, phylogenomic studies, proteome analysis, analysis of polymer hydrolysis metabolites, quantitative PCR, field emission scanning and transmission electron microscopies and fluorescence microscopy are detailed in SI Appendix, Materials and Methods.