2.3. Amino acid analysis
Amino acid compositions were analyzed using an automatic
analyzer (Hitach Model 835-50, Tokyo, Japan) with a C18 column
(5M, 4.6 × 250 nm, Watchers, MA, USA). The reaction was carried
out at 38◦C, with the detection wave length at 254 nm and flow rate
of 1.0 ml/min. All chemical analyses (from each tank) were carried
out in triplicate.