The strategy of salt adaptation is not limited to the aerobic halophilic Archaea. The anaerobic fermentative Halanaerobiales (Bacteria, Firmicutes) also use KCl rather than organic solutes to osmotically balance their cytoplasm, and they also have adapted their intracellular machinery to tolerate the presence of salt [18,47]. The third type of organism, phylogenetically unrelated with the above-mentioned two groups, in which the 'high-salt-in-strategy' was recently identified to occur, is the aerobic red extremely halophilic Salinibacter ruber (Bacteroidetes). The properties of this intriguing organism are discussed below in further depth.