Abstract
The type of peptidoglycan in the cell wall and the ability to transform auxotrophic mutants of Micrococcus luteus ATCC 27141 were determined for 55 strains of micrococci and related organisms. There exists a perfect correlation between these characteristics. Onlystrains containing the unique peptidoglycan of M. luteus (l-Lys-peptide subunit)can participate in the genetic exchange, and it is suggested that all such strains be placed in the species M. luteus.