Taxonomy of the Genus Cellulomonas, Based on Phenotypic Characters and Deoxyribonucleic Acid-Deoxyribonucleic Acid Homology, and Proposal of Seven Neotype Strains

Abstract

Proposed as neotype strains of their respective species are the following: Cellulomonas biazotea ATCC 486, C. cellasea ATCC 487, C. fimi ATCC 484, C. flavigena ATCC 482, C. gelida ATCC 488, C. subalbus ATCC 489, and C. uda ATCC 491. Deoxyribonucleic acid-deoxyribonucleic acid reassociation studies on these and three other reference strains of Cellulomonas clearly revealed seven distinct species: C. biazotea, C. flavigena, C. cellasea, C. fimi, C. gelida, C. uda, and C. cartalyticum. C. subalbus ATCC 489 is identical with C. gelida ATCC 488 on the basis of genetic evidence. These results are confirmed by physiological data. C. subalbus is therefore a junior synonym of C. gelida. The polysaccharide and amino acid composition of the cell wall, the electrophoretic mobility of the L-lactate dehydrogenase, and the utilization of certain sugars and organic acids were found to be useful characters in species differentiation. Although the deoxyribonucleic acid-deoxyribonucleic acid homology values within the genus Cellulomonas range between 20 and 100%, those between strains of Cellulomonas and strains of Arthrobacter, Corynebacterium, and Brevibacterium are lower than 8%. These data, supported by the high guanine plus cytosine content of the DNA, the ability to decompose cellulose, and the similarity in the peptidoglycan types, demonstrate the coherence of the members of the genus Cellulomonas and the validity of the inclusion of this genus in the family Corynebacteriaceae.