Corynebacterium diphtheriae bv. gravis

**Semantic type:** Bacterium

**Definition:** A biovar of Corynebacterium diphtheriae distinguished by its morphogenic and biochemical properties. Biovar gravis is nitrate positive and positive for fermentation of glucose, maltose, and starch. This biovar is one of the two main disease-causing biovars.

**Synonyms:** - CORYNEBACTERIUM DIPHTHERIAE TYPE GRAVIS