Microbial siderophores and their potential applications: a review

Abstract

Siderophores are small organic molecules produced by microorganisms under iron-limiting conditions which enhance the uptake of iron to the microorganisms. In environment, the ferric form of iron is insoluble and inaccessible at physiological pH (7.35-7.40). Under this condition, microorganisms synthesize siderophores which have high affinity for ferric iron. These ferric iron-siderophore complexes are then transported to cytosol. In cytosol, the ferric iron gets reduced into ferrous iron and becomes accessible to microorganism. In recent times, siderophores have drawn much attention due to its potential roles in different fields. Siderophores have application in microbial ecology to enhance the growth of several unculturable microorganisms and can alter the microbial communities. In the field of agriculture, different types of siderophores promote the growth of several plant species and increase their yield by enhancing the Fe uptake to plants. Siderophores acts as a potential biocontrol agent against harmful phyto-pathogens and holds the ability to substitute hazardous pesticides. Heavy-metal-contaminated samples can be detoxified by applying siderophores, which explicate its role in bioremediation. Siderophores can detect the iron content in different environments, exhibiting its role as a biosensor. In the medical field, siderophore uses the "Trojan horse strategy" to form complexes with antibiotics and helps in the selective delivery of antibiotics to the antibiotic-resistant bacteria. Certain iron overload diseases for example sickle cell anemia can be treated with the help of siderophores. Other medical applications of siderophores include antimalarial activity, removal of transuranic elements from the body, and anticancer activity. The aim of this review is to discuss the important roles and applications of siderophores in different sectors including ecology, agriculture, bioremediation, biosensor, and medicine.

Natural product diversity of actinobacteria in the Atacama Desert

“…Siderophores also play a critical role in maintaining microbial life through the expression of virulence and development of biofilms under harsh or threatening conditions, and assist in the extraction of heavy metals from contaminated environments (Saha et al 2016). Additionally, siderophores in many reported cases act as signalling molecules (auto-regulator/quorum sensing molecules) (Bertrand et al 2014).…”

Principales preservadores maderables y exudados microbianos con actividad antagonista al desarrollo en agentes biológicos deletéreos

“…Also, a wide group of bacteria are able to antagonize the development of some fungi using various action mechanisms. This group includes plant growth-promoting rhizobacteria (PGPRs), which, by producing siderophores (Saha et al, 2016), antibiotics (Tariq et al, 2017) or by competition for colonization spaces in roots and the production of organic compounds (COVs), generate an excellent and a distinctive antimicrobial effect (Table 5). Carpóforo anamorfo bifurcado y filamentoso, de himenio inserto en la superficie externa del ascoma (negro), ausente de pie, sabor u olor.…”

“…También, un amplio grupo de bacterias son capaces de antagonizar el desarrollo de algunos hongos mediante variados mecanismos de acción. En este grupo se encuentran las rizobacterias promotoras del crecimiento vegetal (PGPRs), que por medio de la producción de sideróforos (Saha et al, 2016), antibióticos (Tariq et al, 2017) o competencia por espacios de COVs are organic molecules with a molecular mass of <300 Da and their main characteristic is a high vapor pressure that facilitates its volatilization (Zou et al, 2007). Some have anti-fungal potential and can act at a distance by diffusion in the air e.g.…”

“…Algunas especies del género Bacillus producen antibióticos y proteínas insecticidas e.g. B. subtilis producen antibióticos, aunque consideradas PGPRs debido a que ejercen efecto promotor del crecimiento vegetal y un control biológico sobre (Saha et al, 2016). The best siderophore-producing bacteria are found in the bacterial category of PGPRs.…”

“…Esta estrategia de control fúngico se puede realizar mediante los sideróforos, que son compuestos de bajo peso molecular producidos y secretados por raíces vegetales y algunas bacterias, e.g. los sideróforos capturan elementos como el hierro (Fe +3 ) (Saha et al, 2016). Las mejores bacterias productoras de siderófo-ros se encuentran en la categoría bacteriana de las PGPRs.…”