Isolement et propriétés de nouvelles bactéries appartenant au premier groupe morphologique du genre Bacillus et dont le DNA contient près de 55 mol% de guanine + cytosine

Ten endospore-forming, aerobic strains were isolated from pasteurized soil samples by enrichment at 32 °C in a minimal medium containing crotonate, phenylacetate or 2,3-butanediol as sole carbon and energy source. They are rods with a diameter greater than 1 μm, Gram variable, very motile, and peritrichous. The endospores are oval and non-deforming, thus placing the strains in the first morphological group of the genus Bacillus. Poly-β-hydroxybutyrate is not produced in appreciable quantities. The maximum growth temperature is between 48°C and 60°C. They neither ferment glucose nor use nitrate as an electron acceptor. The oxidase reaction is positive. They hydrolyze gelatin and “Tween 80”. All the strains use 23 compounds as sources of carbon and energy. Many characters vary from one strain to another. The average guanine + cytosine content of the DNA is 54.9 ± 1.4mol%. The 10 cultures described differ clearly from Bacillus megaterium and perhaps represent a large new mesophilic, thermotolerant, omnivorous species, sensu Stanier (1976).