The immobilization of Pseudomonas aeruginosa GF31 and its enhancement of biodegradation of cypermethrin were investigated.Zeolite was chosen as a suitable support for the immobilization by taking into account the properties of cypermethrin and mass transfer in the bioremediation.Scanning electron microscope (SEM) images demonstrated that strain GF31 grew well in the pore of the zeolite.After immobilization

cypermethrin removal efficiency was improved significantly from 37% to 61.4% at initial cypermethrin concentration of 100 mg ·L-1 in 6 d.The specific degradation rate of free cells and immobilized cells were 487 and 917 mg·[L·d· (g dry biomass) ]-1 respectively

at 300 mg·L-1 cypermethrin.It was also found that the immobilized cells exhibited higher tolerance to pH and cypermethrin concentration

keeping its activities even at pH 10 or higher cypermethrin concentration up to 800 mg·L-1.The results of actual soil remediation by the immobilized cells showed that cypermethrin degradation could be well described by a first-order reaction rate equation.As compared to natural degradation

cypermethrin half life (t1/2) was shortened from 34.3 d to 8.02 d

which illustrated a good result of bioaugmented remediation by the immobilized Pseudomonas aeruginosa GF31.