抄録
1. Brev. lactofermentum rapidly removed biotin from culture medium. The amounts taken up exceeded the quantities required for maximal growth. Two significant levels of cellular biotin were observed in this micro-organism. They are a minimum level most adequat to the accumulation of L-glutamic acid (approximately 0.5μg/g), and a saturation level (approximately 20μg/g)
2. Biotin stored in cells was metabolically available, if the cells were subsequently placed in a medium lacking in biotin. In the subse-quent culture, the biotin level of cells was gradually reduced to the minimum level (0.5μg/g), as the cells multiplied, and then the accumulation of L-glutamic acid began.
3. The addition of Tween 60 in the subse-quent culture impaired the relation between the level of cellular biotin and the accumula-tion of L-glutamic acid. Since Tween 60 was incapable of preventing biotin from being taken up, it hindered the action of the absorbed biotin. Therefore, even biotin-saturated cells accumulated L-glutamic acid in the presence of Tween 60.
4. Saturated fatty acids with fourteen to eighteen carbons as well as Tween 60 had partial inhibitory effect on the subsequent growth of the biotin-saturated cells.
5. The bioautograms of the acid hy-drolysates of the cells exhibited a characteristic peak near to RF 0.85 and were identical with that of authentic d-biotin, using L. arabinosus as an assay organism. In addition, the growth I of Brev. lactofermentum was supported by the hydrolysate of the cells with minimum biotin, s and the combinability of avidin with the r biotin in the hydrolysate was observed in the f culture of this microorganism. From these observations, the existence of biotin was t evidently demonstrated in the cells.
