Ammonia → L-Tryptophan

Participants

Reaction Conditions

Reaction Steps

A 100 g of the frozen cells of Escherichia coli K-12 SH1001 prepared in Preparation Example 2 and 100 g of the frozen cells of Escherichia coli K-12 YK3005 (FERM BP-1736) prepared in Preparation Example 4 were suspended in 500 ml of the reaction solution (adjusted to pH 9.5 with 25% ammonia)containing 0.1 g of indole, 7.5 g of glycine, 1.6 g of formalin (formaldehyde content: 37%), 100 mg of PLP, 1.0 g of THF and 3.8 g of KCl, and then water was added to the suspension to make its total amount 1,000 ml. This suspension was fed into a 3-liter fermentor (mfd. by Able Inc.) and reacted with stirring at 30° C. During the reaction, pH of the reaction solution was adjusted to maintain at 9.5 with 25% ammonia. Indole was added continuously or intermittently so that the indole concentration in the reaction solution wouldn't exceed 2 mmol/l while monitoring the indole concentration by a high-performance liquid chromatograph (mfd. by Shimazu Corp.). Further, glycine and formaldehyde were added continuously or intermittently so that the L-serine concentration wouldn't exceed the designated levels for the respective test sections shown in Table 2 while monitoring the L-serine concentration in the reaction solution by a high-performance liquid chromatograph(mfd. by Shimazu Corp.). Glycine was added in a total amount of 22.5 g. The L-tryptophan concentration in the reaction solution was monitored by a high-performance liquid chromatograph (mfd. by Shimazu Corp.). The yields of L-tryptophan based on glycine are shown in Table 2.

Provenance & Evidence