BACTERIOLOGICAL STUDIES OF THE FECES FROM METHANE-PRODUCERS AND NONPRODUCERS IN THE EXPIRED AIR

Bacteriological studies of the feces from 4 methane-producers and 11 nonproducers in the expired air were made. In all methane-producers, methane was detectable after incubation of the fecal specimens and methanogenic bacteria were present in their feces. In 7 of the 11 methane-nonproducers, methane was not detectable after incubation of the fecal specimens and methanogenic bacteria were absent in the feces. In the remaining 4 cases, however, positive results were obtained in both tests. The latter cases may not excrete methane in the colon. A methanogenic bacterium was isolated for the first time from the feces of a Japanese methan-eproducer. It was classified to the genus Methanobrevibacter since it was an anaerobic, gram-positive and short rod bacterium.