For lipopeptide production in the stirred tank fermenter, thebacterial immobilization process was optimized to enhance bac-terial colonization on chitosan. Results showed that the bacterialimmobilization should be carried out in 100% of LB medium at pH6 with repeated immobilization for 3 cycles. This process enhancedthe attachment of bacteria on chitosan flake to about 1 × 1010CFU/gimmobilized cells from the third cycle of immobilization (Fig. 4).Therefore, this new immobilization method was applied in the fer-menter operation.