SIDEROPHORE PRODUCTION AND OUTER MEMBRANE PROTEIN SYNTHESIS OF VIBRIO PARAHAEMOLYTICUS STRAIN WITH DIFFERENT SEROTYPES UNDER IRON-LIMITED CONDITION

Abstract

Iron uptake mechanisms were investigated in strains of Vibrio parahaemolyticus with different serotypes. Although the production of siderophore was detected in all the strains tested, they were not able to grow in the presence of high concentrations of the iron chelator EDDHA but were able to grow in the presence of only low concentrations of EDDHA (ranging from lower than 8 to 64μM). Two iron-repressible outer membrane proteins (IROMPs) with molecular weights of 71, 000 (71K protein) and 72, 000 (72K protein) were produced in the strain 3283-61 grown in iron-deficient medium. Kinetic analysis revealed that the 71K and 72K proteins occurred 1.5 and 2.5h, respectively, after downshift from chemically defined medium to iron-deficient medium. Analysis of IROMPs from V. parahaemolyticus strains with different serotypes showed that the patterns of IROMPs from these strains were very similar to that of strain 3283-61: all the strains produced the two IROMPs of 71K and 72K proteins, except one strain, which produced only the 71K protein.