Abstract
Identification of the radioactive metabolite of PaS35SO3H in B. bifidum N4 was undertaken. The strain was incubated with (PaS35SO3)2 Ca for 60 min at 37° in CySS (-) MGM, and after removal of the bacteria, the medium which showed a new radioactive peak on a chromatogram was neutralized and reacted with NEM or HCHO and PABA. By this treatment, the peak disappeared and in turn a new peak emerged in both cases. They were identified as NEM-35SO3H and SMPABA-35S by PEP (1 M HCOOH, pH 2) and radiochemical crystallizations. In the absence of the bacteria, the peak of the radioactive metabolite was not produced by the incubation of (PaS35SO3)2 Ca with CySS (-) MGM, neither produced NEM-35SO3H from (PaS35SO3)2 Ca by NEM treatment. Furthermore, transformation of 35SO42- to H35SO3- by the strain was not observed. These results demonstrate the production of HSO3- from PaSSO3H by B. bifidum N4.
