抄録
Sulfur source in the biosynthesis of biotin from desthiobiotin by washed cells of Saccharomyces cerevisiae, deficient in biotin and sulfur, was investigated. It was elucidated that the radioactive-S of methionine was incorporated into biotin. Biotin-^<35>S was concentrated from the reaction mixture containing 140μc of methionine -^<35>S by the procedure using avidin, described in the previous report. This biotin concentrate contained 0.26μc of ^<35>S. It was found by radioautography, bioautography and paper chromatoscanning that 70% of radioactivity in the biotin concentrate was located in biotin-ralated compounds. The radioactivity was found in biotin, biotin-d-sulfoxide, biotin-l-sulfoxide (?), biocytin and biocytin sulfoxide.
