Isolation and cultivation of spore-forming filamentous bacteria fromPorcellio scaber

An endospore-forming rod-shaped filamentous bacterium was taken from boiled intestines of common sow bugs (Porcellio scaber, isopod crustaceans). The bacteria were grown on peptone – yeast extract medium. As many as 180 cells per filament were counted in culture; filament length was a function of time after germination and oxic conditions. Cultures continued to grow filamentously after 10 successive transfers. The development of spores was inhibited by strict anaerobiosis for 3 months. Spore-forming filaments over 100 μm long in fresh intestinal material were observed only in guts taken from sow bugs cultivated in darkness. Phenotypic tests presented here show this isolate to be a member of the genus Bacillus, most closely resembling B. cereus.