OF BASAL MEDIUM

Hugh and Leifson developed OF Medium to study oxidative and fermentative metabolism of carbohydrates by gram negative bacteria. This criterion is used during taxonomic studies of Enterobacteriaceae. The authors Hugh and Leifson showed that when a gram-negative organism is inoculated in this medium containing a carbohydrate in duplicate, of which one tube is covered with mineral oil to exclude oxygen and the second tube is uncovered; reactions of differential value can be observed. Fermentative organisms will produce an acid reaction in both the covered and uncovered medium. Oxidative organisms will produce an acid reaction in the uncovered medium and give slight growth without change in the covered medium. Organisms which are not classified either as oxidative or fermentative show no change in the covered medium and an alkaline reaction in the uncovered medium.

for di?erentiation of gram negative bacteria on the basis of fermentative and oxidative metabolism of carbohydrates