Siderophore Production by Pseudomonas aeruginosa Isolated from the Paddy Fields of Kuttanad, Kerala

Siderophores are low-molecular-weight chelating agents excreted under iron-limited conditions by microorganisms which strongly and specifically bind, solubilise and deliver iron to microbial cells via specific cell surface receptors. In natural habitats, certain bacteria can acquire iron by uptake of exogenous siderophores through receptors showing that they can utilize siderophores produced by other microorganisms as an iron source. This property can be made use of in increasing the nutritional value of agricultural areas. Kuttanad is well noted for paddy cultivation below sea level in Kerala. Considering its agricultural importance, this area was selected for the isolation of siderophore producing bacteria. One of the isolates, KSB3, which was later identified as Pseudomonas aeruginosa, was screened for the ability to produce siderophore. Siderophore production by submerged fermentation and the parameters influencing siderophore production were optimized. The chemical nature of the siderophore produced by KSB3 was also determined.