Abstract
We have isolated the fruiting myxobacterium Stigmatella aurantiaca from wood and bark, and have examined some aspects of its ecology, morphology, physiology and taxonomy. Vegetative cells were Gram-negative, spindle-shaped rods 5.2 to 8.4 μ long and 0.65 to 0.74/μ wide. The myxospores were optically refractile short rods measuring about 3.2 × 1.0 μ. Fruiting bodies were usually bright orange or red brown and consisted of a stalk 60 to 140 μ high bearing 1 to 20 cysts at its top. Most cysts were spherical or ovoid, measuring 40 to 60 μ by 25 to 45 μ. S. aurantiaca was cultivated in liquid culture in a dispersed vegetative state or on solid media, producing either fruiting bodies or vegetative forms. Optimal vegetative growth was obtained with a medium containing Casitone, glucose and salts. The optimal temperature for growth was 300. Cultures could be preserved by storage of vegetative forms at − 600 or of dried myxospores or fruiting bodies at − 180. Dried myxospores were resistant to desiccation and elevated temperatures. We propose that Stigmatella, which had been incorporated into the genus Chondromyces, be re-established as a separate genus within the Polyangiaceae. We further propose the inclusion of Chondromyces among the Sorangiaceae.