Abstract
Carbethoxythiamine (I) and carbobutoxythiamine (II) were both more absorbed by cells of Kloeckera apiculata than dicarbethoxythiamine (III), when an equimolar amount of each compound was incubated with a suspension of Kloeckera cells in saline. Thiamine-HCl was almost completely absorbed by Kloeckera cells on the same condition but it was not absorbed by heat-sterilized cells, while (I), (II) or (III) showed better absorption to sterilized cells than thiamine-HCl. (I) was always more active in stimulating the growth of Kloeckera. This was proved not only by comparison of optical densities of the brothes but also by that of dry weights and nitrogen contents of the cells after incubation although the thiamine content of Kloeckera cells corresponding to (I) was not proved to be higher than that to thiamine.
