A RAPID METHOD FOR THE DETERMINATION OF SUGAR IN BACTERIAL CULTURES

Abstract

A micro method has been developed for determining 8 sugars commonly used in culture media. The culture is neutralized, clarified with lead acetate, deleaded with sodium phosphate and again brought to neutrality. The clarification and deleading may be combined in 1 operation, effecting a gain in time and not appreciably lessening accuracy. The solution clears in 3 minutes and the aliquot may be removed directly with a pipette. When only sugar fermentability is involved, a determination in most cases may be made directly on the culture without clarification. An aliquot of the clarified solution is added to the Shaffer-Hartmann micro reagent and the procedure of that method followed. A table gives the mgm. of sugar directly from the titration of thiosulphate. Factors for calculating the quantity of arabinose, xylose, galactose, fructose, maltose, lactose, and invert sugar have been determined.