What a strain is and how many strains make up a natural bacterial population remain elusive concepts despite their apparent importance for assessing the role of intra-population diversity in disease emergence or response to environmental perturbations. A research team sequenced 138 randomly selected Salinibacter ruber isolates from two solar salterns and assessed these genomes against companion short-read metagenomes from the same samples. In its paper published in Nature Communications, the team says its methodology and ANI thresholds outlined should represent a useful guide for future microdiversity surveys of additional microbial species. The researcher include Ph.D. Scholar Roth E. Conrad and Professor Kostas Konstantinidis, both in the School of Biological Sciences. Konstantinidis is also the Richard C. Tucker Professor in the School of Civil and Environmental Engineering.