In vitro studies of siderophore production by wild type and rifampicin resistant strains of fluorescent Pseudomonads

Wild type (Rif−) and rifampicin resistant (Rif+) isolates of fluorescent Pseudomonads were grown in King’s B liquid medium in the presence and absence of iron and subcultured every 48 h for 12 days. Growth rates and the proportion of non-fluorescent colonies were measured. All Rif+ isolates when grown in the presence of iron produced a significantly higher proportion of non-fluorescent colonies. One Rif+ isolate had a reduced growth rate.