ABSTRACT
Iron is the fundamental cofactor for conducting numerous metabolic processes of organisms. It plays a vital role by regulating biosynthesis of vitamins, antibiotics, toxins, cytochromes, nucleic acid, and microbial biofilm formation by regulating the surface motility of microorganism. Even though abundant iron is available in the earth’s crust and environment, its ferric form is insoluble and inaccessible at physiological pH (7.35-7.40). In such condition, the concentrations of dissolved iron is approximately 10−10-10−9 M in precipitate form, whereas the essential level for living organisms is around 10−7-10−5 M. Therefore, in order to survive under such iron-stress condition, most of the microorganisms synthesize microbial iron chelates, that is, organic compounds with low molecular 164weight below 1000 Daltons.Such compounds are called siderophores. Siderophores show ability to obtain iron from the surroundings and make it available to microbial cells by forming its soluble complexes. In plants, iron plays a prominent role in the biosynthesis of chlorophyll, thylakoid, and chloroplast development. Accordingly, iron deficiency in plants not only affects their growth but also increases the susceptibility towards various diseases and disorders resulting in poor micronutrient content and adverse impact on plant health as well as on the health of animal and humans. Siderophores shows a wide variety of applications, as they can efficiently act as plant growth promoter, biocontrol agent, biosensor, and can be utilized in biomedicine. They play an important role in bioremediation and also exhibit the potential to biodegrade petroleum hydrocarbons. Although, large number of siderophores produced by different microor-ganisms have been documented, amazing structural variations can be seen in bacterial siderophores and they show promising potential to overcome problems related to iron deficiency. This chapter presents the overview of bacterial siderophores, their classification, transport mechanism, and their production method. This chapter also discussesabout the qualitative and quantitative detection methods for different types of siderophores, such as chemical assay, bioassay by traditional as well as modified methods. It also proposed the method of their crystallization, identification, and characterization. Characterization of siderophores is performed by FTIR, LC-MS, ESI /MALDI Mass spectra and NMR, etc. This chapter has illustrated the elaborative applications of bacterial siderophores for sustainable future.
