Essential amino acid L-phenylalanine prepn. - by reacting trans cinnamic acid with ammonium carbonate and phenylalanine ammonia lyase

摘要

L-phenylalanine (I) is produced by reacting trans-cinnamic acid (II), with ammonium ions derived from ammonium carbonate in the presence of phenylalanine ammonia lyase (III). - The ammonium carbonate may be produced by dissolving (II) in aq. NH3 and then passing CO2 through until the required pH of 9 to 11 is reached. (II) is present in the soln. at the rate of 5 to 25 g/l, pref. 10 to 20 g/l. (III) can be obtd. from a microbial source as described in GB2127821. A suitable organism is Rhodotorula rubra. - The ammonium carbonate is removed by volatisation and the remaining soln. conc. to an L-phenylalanine level of 75 to 300 g/l, pref. 150 to 200 g/l. On cooling, (I) is pptd.