The concentration of arginine,
asparaginic acid, glutamate, cysteine, lysine, isoleucine and tyrosine
increased constantly; for example, the concentration of aspartic acid
increased from 14.42 mg/L at 0 d to 34.28 mg/L in the endfermentation
stage and glutamic acid increased from 35.43 mg/L at 0 d
to 127.80 mg/L in the end-fermentation stage