Taxonomic parameters revisited: tarnished gold standards

Abstract

Molecular properties are included in the definition of a ‘species’. Exciting new findings announced here by Erko Stackebrandt and Jonas Ebers show that a 16S rRNA gene sequence similarity range above 98.7–99 % should be mandatory for testing the genomic uniqueness of a novel isolate. This overturns the old value of 97 % and will greatly facilitate the work of taxonomists.