Al.li.son.ella. N.L. dim. suff. -ella; N.L. fem. n. Allisonella named after the American microbiologist Milton J. Allison, a prominent rumen microbiologist who isolated Oxalobacter formigenes, a ruminal bacterium that decarboxylates oxalate.

Firmicutes / “Clostridia” / Clostridiales / Veillonellaceae / Allisonella

Cells are ovoid shaped, nonmotile, and form diploids or chains. Spores not observed. Cells stain Gram-negative. Resistant to ionophore and monensin. Catalase-, oxidase-, and indole-negative. Nonfermentative, facultative anaerobic, and chemoheterotrophic. Utilizes histidine as sole energy source. Produces histamine and CO₂ as end products from histidine. Growth occurs in medium containing yeast extract, butyrate, and histidine. On the basis of 16S rRNA gene sequence comparisons, the genus Allisonella is a member of the family Veillonellaceae.

DNA G+C content (mol%): 45–48 (HPLC).

Type species: Allisonella histaminiformans Garner, Flint and Russell 2003, 373^VP (Effective publication: Garner, Flint and Russell 2002, 504.).