Abstract
Both thiamine propyl disulfide (TPD) and S-carbethoxythiamine (CET) stimulate the growth of K. apiculata but they show the following different behaviors.
1. When CET is reduced to thiamine extracellularly by Takadiastase, it shows the same activity as thiamine on the growth of the bacterium.
2. When TPD is reduced to thiamine by cysteine extracellularly, it shows the activity greater than thiamine.
3. When TPD accumulated in the cells in saline are diluted with the medium and incubated, they show the same activity as thiamine, but when CET is treated in the same way, it showes the activity greater than thiamine.
4. TPD is easily reduced to thiamine in the presence of the yeast suspension but CET is slowly converted to thiamine on the same treatment.
