Biochemical Effects of Fatty Acid and its Derivatives on l-Glutamic Acid Fermentation

Brev. lactofermentum rapidly took up biotin from culture medium and stored it in the cells. The saturation level of the stored biotin (3.8 × 10⁴ molecules/cell) exceeded the level required for the maximum growth by ten times, and the minimum level (1.3 × 10³ molecules/cell) was the most adequate to the accumulation of l-glutamic acid. The stored cellular biotin over the minimum level was metabolically available in the subsequent culture lacking in supplemented biotin. The cellular biotin was gradually reduced to the minimum level with the multiplication of the cells, and them the accumulation of l-glutamic acid was observed. This relation between the level of cellular biotin and the accumulation of l-glutamic acid was impaired by the addition of Tween 60 or some saturated fatty acid. In the presence of biotin and Tween 60 the biotin-saturated cells turned into cells capable of accumulating l-glutamic acid keeping the maximum level; and in the same medium the cells having the minimum amount of biotin took up biotin and then were saturated with it, and yet the cells preserved the acid-accumulating property. It was confirmed with the use of bioautographic technique and avidin test that the biotin released from the cells by acid hydrolysis was identical with authentic d-biotin.