To screen the phylogenetically-nearest members of Cellulosimicrobium cellulans for the production of cellulosome-like multienzyme complexes and extracellular beta-xylosidase activity against 7-xylosyltaxanes and to get corresponding molecular insights. Cellulosimicrobium (family Promicromonosporaceae) and all genera of the family Cellulomonadeceaec produced both cellulosome-like multienzyme complexes and extracellular beta-xylosidase activity, while the other genera of the family Promicromonosporaceae did not. Multiple sequence alignments further indicated that hypothetic protein M768_06655 might be a possible key subunit. This is the first report that many actinobacteria species can produce cellulosome-like multienzyme complexes. The production of cellulosome-like complexes and the extracellular beta-xylosidase activity against 7-xylosyltaxanes might be used to differentiate the genus Cellulosimicrobium from other genera of the family Promicromonosporaceae.