Question

You have isolated an aerobic gram-positive, endospore-forming bacterium that grows well on nutrient agar. To which of the following groups does it most likely belong? A) Phototrophic bacteria B) Gammaproteobacteria C) Deltaproteobacteria D) Bacillales E) Can't tell

Answer 1

The right answer is Bacillales.

The Bacillales family includes the genus Bacillus which has endospores in its cytoplasm.

The endospore is formed in the cytoplasm when the environmental conditions are unfavorable (nutritive stress, desiccation, heat ...). The endospore allows the bacteria to survive these adverse conditions in a slower state of life (dormant state). The endospore thus represents a form of resistance but also a form of dissemination.

Clostridium, Bacillus, Sporosarcina are examples of bacteria that can sporulate.