A simple rapid procedure for obtaining axenic cultures from monoxenic cultures of myxomycete plasmodia

Axenic culture of myxomycete plasmodia has been attempted from time to time by various authors, but with very little success. From over 500 known species of myxomycetes, fewer than 20 species have been reported in axenic culture to date, including axenic myxamoebal cultures. In these cultures, the plasmodia required either complex media, or a killed bacterial supplement for growth. Furthermore, the time required for attaining the axenic state varied from several months to years. In the present study, a simple, rapid procedure has been developed to render monoxenic plasmodial cultures axenic. This procedure is based on our discovery that plasmodia have certain unusual substrate preferences that are inhibitory to the associated bacteria using Physarella oblonga as a model. The presence or absence of the bacteria could be ascertained through incubation in four different bacteriological media and by the use of a differential staining technique.