Studies on the thermophilic actinomycetes. I. Methods of cultivation.

A total of 1,000 isolates of thermophilic actinomycetes representing two genera, Streptomyces and Thermoactinomyces, were studied. Media for cultivation and for physiological studies were designed. Differences between the two genera are noted and taxonomic criteria for the genus Thermoactinomyces are suggested. The importance of the nutritional environment to the thermophilic habit is noted.