Effect of Antifungal Agents on the Carbohydrate Metabolism of Kluyveromyces fragilis1

Pimaricin and nystatin, two antifungal agents, inhibited endogenous respiration and. anaerobic and anaerobic utilization of sugars by Kluyveromyces fragilis. Three sugars, lactose, glucose, and were metabolized by a somewhat similar process as judged by the extent of inhibition caused by the antifungals, both aerobically and anaerobically. The degree of inhibition by the antifungals was more pronounced under anaerobic conditions. There existed a direct, but not proportional, relationship between concentration of antifungals and extent of inhibition. Nystatin impaired carbohydrate metabolism slightly more than did pimaricin. Also, K. fragilis contained lactase which was found to be a constitutive enzyme and was inhibited by the two antifungal agents.