BECKER, B. (Rutgers, The State University, New Brunswick, N.J.), M. P. LECHEVALIER, AND H. A. LECHEVALIER. Chemical composition of cell-wall preparations from strains of various form-genera of aerobic actinomycetes. Appl. Microbiol. 13:236-243. 1965.-Cell-wall preparations were made from more than 140 strains of aerobic actinomycetes representing most of the form-genera that have been proposed. All cell-wall preparations contained as major constituents glucosamine, muramic acid, alanine, and glutamic acid. In addition, cell-wall preparations from various types of streptomycetes and strains of Microellobosporia contained glycine and LL-a, e-diaminopimelic acid; those from strains of most Actinoplanaceae and micromonosporae contained glycine and meso-a-e-diaminopimelic acid; those from strains of Thermoactinomyces, Microbispora, Dermatophilus, and nocardiae of the madurae-pelletieri group contained meso-a, e-diaminopimelic acid; and those from strains of Thermomonospora, Micropolyspora, and most nocardiae contained meso-a,ce-diaminopimelic acid, arabinose, and galactose. All the strains used were also studied morphologically.