抄録
Two new kinds of riboflavin decomposing bacteria, strains 14-I and A-I, were isolated from human feces. Both organisms are Gram-positive, non-sporeforming and of motile rods, but differ from each other immunologically and bacteriologically in detail and also from all the other known riboflavin decomposing bacteria. Strain 14-I decomposed riboflavin intensely, whereas A-I did feebly. But the decomposition by A-I was much augmented when cultured mixed with a certain bacterium, strain A-IV, A-IV, though isolated from the same feces as A-I was done, is a Gram-positive, non-sporeforming and of motile rod, but showed no ability to decompose riboflavin in its sole culture. In either 14-I or A-I and A-IV, the decomposition was proved to produce lumichrome, and revealed to be promoted by shake culture, but it did not occur at all when glucose was added to culture medium.
