To obtain a large amount of pyoverdine, P. aeruginosa PA1 was grown in synthetic succinic acid (SSA) medium consisting of 3.0 g/L KH2PO4, 6.0 g/L K2HPO4, 0.1 g/L MgSO4·7H2O, 1.0 g/L (NH4)2SO4 and 4.0 g/L succinic acid, with the pH adjusted to 7.0 using a 1 N NaOH solution before sterilization