What a microbial strain is and how many strains make up a natural bacterial population remain elusive concepts. Here, Viver et al. analyse Salinibacter ruber isolates and metagenomes from two solar salterns, revealing gaps within the species sequence space that they use to define and quantify sub-species categories, such as genomovars and strains, that co-exist in a saltern pond.
- Tomeu Viver
- Roth E. Conrad
- Ramon Rossello-Mora
