FIG. 1.

Identification of an O1-antigen-deficient mutant. (A) Detection of anguibactin using CAS agar plates (48). The identity of anguibactin as the CAS-reactive product was verified using a bioassay as previously described (55). Strains tested were as follows: 1, 531A (wild-type parent); 2, TW19 (transposon mutant). (B) Scheme of the gene cluster identified by transposon-directed cloning of mutant TW19. The point of transposon insertion in TW19 is indicated with a lollipop symbol, and the SalI restriction site modified in mutant 531A-10 is also indicated. (C) SDS-PAGE analysis of proteinase K-digested whole-cell lysates visualized by silver staining. Lanes: 1, 531A (wild-type parent); 2, TW19 (transposon mutant).