USE OF DIFFERENTIAL RUMEN FLUID-BASED CARBOHYDRATE AGAR MEDIA FOR CULTURING LACTASE-SELECTED CECAL BACTERIA FROM CHICKENS

A rumen fluid-based differential carbohydrate agar medium for enumerat ing chicken cecal carbohydrate-utilizing bacteria was tested. Eleven b acteria isolated from a continuous-flow culture that had been seeded w ith chicken cecal contents were inoculated on fifteen different media in an anaerobic environment. These media included various levels of nu men fluid (0%, 5%, 10%, 16%) and carbohydrate (glucose [GLU], galactos e [GAL], lactose[LAC]). Viable cell recovery (colony-forming units [CF U]/direct cell counts x 100%) was higher for 16% rumen fluid-supplemen ted carbohydrate media than the lower concentrations of rumen fluid-su pplemented carbohydrate media. In addition, average viable cell recove ry of all 11 bacteria on differential carbohydrate media were signific antly (P < 0.05) higher in galactose and lactose media than on the glu cose media. Data indicated that 16% rumen-fluid based media can be use d to enumerate anaerobic, lactose-fermenting subgroups of chicken ceca l bacteria.