中国生物工程杂志

L-theanine ( γ-glutamylethylamide ) is the main free amino acid component of tea and its favorable physiological effects on mammals have been reported. An enzymatic method for optically pure L-theanine production with a new L-aminoacylases-production fungi Cunnighamella echinulata 9980 was developed. The optimum conditions for enzymatic catalysis were at pH 6.5 with 50 mM N-Acyl-DL-theanine and 40 mM CoCl2. After 12-h incubation at 50℃, 22.5 mM L-theanine was obtained, the conversion rate against N-Acyl-L-theanine being 90%. This is the first report that Cunnighamella echinulata and the aminoacylase were applied in preparation of L-theanine.