抄録
In the course of a search program to acquire rare actinomycete species from natural habitats, a remarkable organism was isolated from a grass blade that formed true synnemata and had motile arthrospores and was named as the new genus Actinosynnema. By a selective isolation method based on the characteristics of Actinosynnema, Actinosynnema-like organisms have been effectively isolated from soil habitats, and subsequently, the new genus Actinokineospora was discovered. Furthermore, a number of “Catenuloplanes”-like organisms have been obtained. In this way, Sporichthya, Actinosynnema, Actinokineospora and “Catenuloplanes” have come to be recognized as rare genera having motile arthrospores. No doubt these rare genera await establishment of their status in the rational actinomycete taxonomy.