IN-VITRO METABOLISM OF RADIOLABELED CARBOHYDRATES BY PROTECTIVE CECALANAEROBIC-BACTERIA

Cecal anaerobic bacteria from adult broilers were cultured in media co ntaining .25% glucose or .25% lactose. Media also contained either [C- 14]-labeled lactose, glucose, galactose, or lactic ac id as metabolic tracers. Cultures were analyzed at 4, 8, and 12 h for pH, radiolabeled and unlabeled volatile fatty acids, and lactic acid. The pH values of cultures containing .25% lactose were significantly (P < .05) higher than the pH values of cultures containing.25% glucose. Lactose culture s reached their lowest pH more slowly than glucose cultures. Concentra tions of unlabeled volatile fatty acids increased and lactic acid decr eased during incubation of the cultures. Radiolabeled sugars and lacti c add were more readily metabolized to volatile fatty acids in media c ontaining lactose than in media containing glucose. The preferred meta bolism of [C-14]substrates, independent of media carbohydrate, was in the following order: lactic acid > galactose, lactose > glucose. The v olatile fatty acids in which radiolabel was most concentrated were ace tic acid, propionic acid, or butyric add.