FERMENTATION MEDIUM FOR NEISSERIA

Neisseria species are oxidative i.e. they produce acid from carbohydrate by oxidation. Because these species are oxidative and produce less acid from carbohydrates than do fermentative organisms and because they also produce ammonia from peptones which may neutralize any acid produced from carbohydrates, acid production is determined in a medium with a low protein/carbohydrate ratio and a sensitive indicator such as phenol red.
Fermentation Medium for Neisseriae is recommended for studying the fermentation reactions of fastidious organisms such as Neisseria. This medium is the modification of the medium originally formulated by Vera. Neisseria species oxidize the added carbohydrates to yield acids. The acids thus formed change the colour of the pH indicator, phenol red form orange to yellow. The organism also degrades the peptone source to yield ammonia. The alkalinity thus formed causes the phenol red to change to pink. However, if the acidity formed by carbohydrate metabolism is greater than the alkalinity formed by peptone degradation, the medium remains yellow in colour.

for studying fermentation reaction of fastidious microorganism such as Neisseriae