Buchnera is 3 μm in diameter and has some of the key characteristics of its Enterobacterales relatives, such as a Gram-negative cell wall.

However, unlike most other Gram-negative bacteria, Buchnera lacks the genes to produce lipopolysaccharides for its outer membrane.

The long association with aphids and the limitation of crossover events due to strictly vertical transmission has seen the deletion of genes required for anaerobic respiration, the synthesis of amino sugars, fatty acids, phospholipids, and complex carbohydrates.

[7] Buchnera also increases the transmission of plant viruses by producing symbionin, a protein that binds to the viral coat and protects it inside the aphid.

The initial studies on Buchnera later led to studies on symbionts of many groups of insects, pursued by numerous investigators, including Paul and Linda Baumann, Nancy Moran, Serap Aksoy, and Roy Gross, who together investigated symbionts of aphids, tsetse flies, ants, leafhoppers, mealybugs, whiteflies, psyllids, and others.