抄録
1. Remarkable changes of growth curve were caused by varying the addition time of Tween 60, though the amount of the ester and the concentration of biotin were not varied. These changes of growth curve cor-responded to those caused by the concentra-tion of biotin in the medium which did not contain Tween 60.
2. On the accumulation of L-glutamic acid, the addition time of Tween 60 was the most decisive. When added later than optimum time, the effect of Tween 60 gradually became less according as the delay of the addition.
3. More than 1.0mg/ml of Tween 60 was required for satisfactory effects. By the incre-ment of the amount, however, the more effect was not gained.
4. The pattern of fermentation course in B20-T1 medium agreed closely with the pat-tern in B3 medium. This suggests that identi-cal cells with B3 cells were grown in B20, medium by the addition of Tween 60, which was supported by microscopic ovservation on the shapes of the two kinds of cells.
5. A difference found between B3 cells and B20-T1 cells was as to the content of cellular biotin. B3 cells which was capable of accumu-lating L-glutamic acid contained deficient biotin in them, whereas the biotin contents were high in B20-T1 cells and B500-T2 cells which also accumulated L-glutamic acid. Biotin was taken up into the cells rapidly during initial period of fermentation, and yet Tween 60 neither prevented the uptake of biotin nor controlled the level of cellular biotin.
6. Close interrelation was observed between final growth and the yield of L-glutamic acid irrespective of adding Tween 60 or not.
