Isolation of the extreme halophiles from rock salt

Extreme halophiles are organisms that require 1.5 M-5.5 M NaCl concentrations (5.5 M is the saturation limit of NaCl) for their optimum growth. Over 100 species have been described as extreme halophiles, and were isolated from solar saltern, salt deposit, rock salt, and sometimes from non-salty environment such as forest soil. During our recent attempt to isolate extreme halophiles, 13 strains including candidate novel species have been isolated from rock salt of various localities. Based on the phylogenetic status, 12 strains were strongly suggested to be 3 kinds of novel species (one of archaea and two of bacteria). Interestingly, Himarayan rock salt gave three different species including two novel species.