Abstract
The formation of biotin from DL-desthiobiotin by washed cells and protoplasts of Bacillus megaterium was investigated. When the cells were fractionated into cell wall, cytoplasmic membrane and cytoplasm after the formation of biotin, the greater part of the synthesized biotin was found to be present in the cytoplasm. It was also found that the protoplasts could synthesize biotin as well as the intact cells. However, the amount of synthesized biotin was only about 1/2 of that to be expected in the washed cells. The biotin-synthetic activity of the treated protoplasts was lost as the structure was disintegrated (by phase contrast microscopy). That is, the protoplasts keeps clearly the form and the cytoplasm maintains the ability of the formation, but when the protoplasts are bursted by osmotic shock the ability is lost completely.
