Recovery and immunity activity of carocin S2. (A) Antibacterial activity of carocin S2 from different strains. The indicator was Pcc strain SP33. Strain number: 1, F-rif-18; 2, TF1-2; 3, TF1-2/pMS2KI; 4, DH5α/pMS2KI; 5, DH5α. (B) Assay for caroS2I. The colony and inoculated strains were F-rif-18. The indicator strains were: 1, SP33; 2, SP33/pGEM-T easy; 3, SP33/pGS2I.