Desferrioxamine E produced by an indigenous salt tolerant Pseudomonas stutzeri stimulates iron uptake of Triticum aestivum L.

Abstract

Siderophore are iron-scavenging biomolecules secreted by a variety of microorganisms in the environment that promote plant growth. In this study, we have identified a hydroxamate type siderophore desferrioxamine E produced by an indigenous salt tolerant Pseudomonas stutzeri strain SGM-1 under iron deficient condition. This bacterial strain was previously isolated from the saline-sodic soil sample on the basis of its salt tolerance through media enrichment. This strain could withstand at increasing salt concentrations (up to 12% w/v NaCl) and tolerated stress of acid as well as alkalinity, even grew over wide temperature ranges. Under iron deficient condition this isolate produced siderophore which was determined qualitatively by universal Chrome Azurol-Sulphonate (CAS) assay and quantitatively by spectrophotometry from the broth supernatant, also, its chemical type was determined by various type detection tests. Identification by liquid chromatography and mass spectrometry showed the hydroxamate type siderophore was desferrioxamine E. The efficacy of the desferrioxamine E was assessed for increasing the iron content of wheat (Triticum aestivum) plant, validated through Microwave Plasma Atomic Emission Spectroscopy (MP-AES). It is suggested that this strain is a useful plant growth promoting bioinoculant for enhancing iron content under stressed conditions for sustainable agricultural practices.