They are not motile. Some species are pigmented. Some species will not grow on simple bacteriological media and may require blood or ascitic fluid for growth as well as increased CO2 pressure. They have a functioning tricarboxylic acid cycle and can use the Entner-Doudoroff and pentose phosphate shunt.
Acid is formed from glucose by some strains and some can ferment other sugars.
Neisseria is the type genus. These are currently divided into two groups on the basis of pigmentation and sugar metabolism. There is a possible third group, Branhamella catarhalis , which shows some relationships with groups 1 and 2 but differs in a number of features including the ability to hydrolyse tributyrin, reduce nitrate and produce DNAase. These strains are non-pigmented and form transluscent colonies. They are generally asaccharolytic.