Oblon, Spivak, McClelland, Maier & Neustadt
Method for producing L-3,4-dihydroxyphenylalanine by precipitation of anhydrous crystals
 A method for producing L-3,4-dihydroxyphenylalanine comprising contacting microorganism cells having .beta.-tyrosinase activity with catechol, pyruvic acid and ammonium ion or with catechol and L-serine, at a temperature lower than 25.degree. C. in the presence of anhydrous crystals of L-3,4-dihydroxyphenylalanine. L-3,4-dihydroxyphenylalanine formed from said contacting precipitates as anhydrous crystals in the reaction mixture, and the thus-precipitated anhydrous crystals can be collected. According to the method of the present invention, crude crystals of L-3,4-dihydroxyphenylalanine having a high purity may be obtained at a high yield of recovery. 
Ajinomoto Co., Inc.
Y C
Y10S C12P
additional inventional
Takuya Makoto Katsuo
Kotani Takeuchi Iizumi