Secretion of lipase by P. fluorescens harboring various plasmids. (A) The activity estimation of culture supernatant. P. fluorescens SIK W1 organisms harboring different plasmids were grown at 25°C in LB medium. The cells were harvested at the stationary phase when they reached an OD600 of around 3.0. Extracellular lipase activities were estimated by the pH titration method, and the activity is represented as relative value to the activity produced by P. fluorescens (pAJH11 pAJH10) (set as 100%). (B) Immunodetection of the lipase culture supernatant. Culture supernatant of 0.04 OD equivalent (12 μl of culture supernatant) was subjected to SDS-PAGE, transferred to nitrocellulose membrane, and analyzed by immunodetection. One OD equivalent corresponds to 1 ml of culture, OD600 = 1. Lanes: 1, no plasmid; 2, pAJH3; 3, pAJH5; 4, pAJH10; 5, pAJH11; 6, pAJH3 pAJH10; 7, pAJH11 pAJH10.