Characterization Of Siderophores Research Articles

A Practical Toolkit for the Detection, Isolation, Quantification, and Characterization of Siderophores and Metallophores in Microorganisms.

Siderophores are well-recognized low-molecular-weight compounds produced by numerous microorganisms to acquire iron from the surrounding environments. These secondary metabolites can form complexes with other metals besides iron, forming soluble metallophores; because of that, they are widely investigated in either the medicinal or environmental field. One of the bottlenecks of siderophore research is related to the identification of new siderophores from microbial sources. Herein we have compiled a comprehensive range of standard and updated methodologies that have been developed over the past few years to provide a comprehensive toolbox in this area to current researchers.

Characterization of siderophore from probiotic Bacillus spp. strain isolated from traditional fermented food of the Himalaya

Characterization of siderophore from probiotic Bacillus spp. strain isolated from traditional fermented food of the Himalaya

Artificial Siderophores with a Trihydroxamate‐DOTAM Scaffold Deliver Iron and Antibiotic Cargo into the Bacterial Pathogen Escherichia coli

AbstractInfections with multidrug‐resistant Gram‐negative bacteria constitute a silent pandemic threat that is increasing globally. A major technical and scientific hurdle hampering the development of efficient antibiotics against Gram‐negative species is the low permeability of their outer membrane that prevents the entry of most small molecules into the cells. This can be overcome by targeting active iron transport systems of the pathogens in a Trojan‐Horse strategy that makes use of drug‐loaded artificial siderophores. While we utilized catechols as iron‐binding motifs in previous work, this study reports the design, synthesis and characterization of siderophores with a DOTAM scaffold that was substituted with three hydroxamate arms allowing for a hexacoordination of iron. Their iron‐chelating capabilities were shown colorimetrically, and the ability of compound 1 to deliver iron into Escherichia coli in a chelation‐specific manner was proven by a growth recovery assay. A covalent siderophore‐ciprofloxacin conjugate exerted antibiotic effects against E. coli, albeit it was less potent than the free drug. The study qualifies artificial DOTAM siderophores with hydroxamate binders as scaffolds for bacterial Trojan Horses. This contribution for honoring my mentor Helmut Schwarz echoes two motifs of my work with him: Hydroxylamin, the topic of my first paper ever, and the fascinating properties of iron ions, studied in the gas phase during my Ph.D. Thesis, became a core subject of our current chemical biology research on antiinfectives.

Characterization of siderophores from Escherichia coli strains through genome mining tools: an antiSMASH study

Although urinary tract infections (UTIs) affect many people, they are usually a disease observed in women. UTIs happen when exogenous and endogenous bacteria enter the urinary tract and colonize there. Cystitis and pyelonephritis occur when bacteria infect the bladder and the kidneys, respectively. UTIs become much serious if the bacteria causing the infection are antibiotic resistant. Since the pathogenic microorganisms have been adopted to current antibiotics via genetic variations, UTIs have become an even more severe health problem. Therefore, there is a great need for the discovery of novel antibiotics. Genome mining of nonpathogenic and pathogenic Escherichia coli strains for investigating secondary metabolites were conducted by the antiSMASH analysis. When the resulting secondary metabolites were examined, it was found that some of the siderophores are effective in UTIs. In conclusion, since the siderophore production in E. coli is directly related to UTIs, these molecules can be a good target for development of future pharmaceutical approaches and compounds. Siderophores can also be used in industrial studies due to their higher chelating affinity for iron.

BIOASSAY, CHARACTERIZATION AND ESTIMATION OF SIDEROPHORES FROM SOME IMPORTANT ANTAGONISTIC FUNGI

The primary mechanisms of plant disease suppression by biological control agents are by production of antimicrobial secondary metabolites like siderophores, antibiotics, volatile substances etc. Siderophores are low molecular iron chelating compounds produced by fungi and bacteria under iron stress condition. The present study is focused on the detection, estimation and characterisation of siderophores from different soil borne fungal biocontrol agents like Trichoderma spp., Beauveria spp. and Metarhizium spp. Isolates of Trichoderma have shown positive results in CAS agar plate whereas Beauveria and Metarhizium have shown negative results. The isolates with positive results were opted for characterization and quantitative estimation of siderophore. T. harzianum produced a maximum percentage of siderophore (85.00%), followed by T. viride (65.50%), T. asperellum (60.27%) and T. longibrachiatum (45.50%). While studying the typification of siderophores, it was found that T. harzianum recorded with maximum hydroxymate and carboxylate production whereas T. viride, T. asperellum and T. longibrachiatum recorded with lesser production of hydroxymate and carboxylate as confirmed by color intensity. But none of the isolates was recorded with catecholate production. Through spectrophotometric analysis, it has been found that slightly alkaline pH was more favorable for the siderophore production for different spp. of Trichoderma. The productions of siderophore from Trichoderma spp. not only scavenge iron which lead to inactivation of those enzymes of the pathogen where iron plays the critical role as cofactor which supplies that iron to the host plant resulting in plantgrowth promotion. Siderophore also has a high degree of influence on medical science in MRI imaging. So mapping of different strains of Trichoderma with high antagonistic efficacy along with profound potency of siderophore production will encourage eco friendly management of fungal diseases on crops, crop improvement and enrichment of medical science

Characterization of microbial siderophores by mass spectrometry

Siderophores play important roles in microbial iron piracy, and are applied as infectious disease biomarkers and novel pharmaceutical drugs. Inductively coupled plasma and molecular mass spectrometry (ICP-MS) combined with high resolution separations allow characterization of siderophores in complex samples taking advantages of mass defect data filtering, tandem mass spectrometry, and iron-containing compound quantitation. The enrichment approaches used in siderophore analysis and current ICP-MS technologies are reviewed. The recent tools for fast dereplication of secondary metabolites and their databases are reported. This review on siderophores is concluded with their recent medical, biochemical, geochemical, and agricultural applications in mass spectrometry context.

Hydroxamate Siderophore from Bacillus sp SD12 Isolated from Iron Factory Soil

The present study reports siderophores production from bacteria isolated from Iron factory soil and its antifungal activity. Of the twelve morphologically different bacterial cultures isolated from iron factory soil, Kanchipuram, only two strains SD6 and SD12 showed siderophores production in Chrome Azurol S assay. Strain SD12 which showed maximum siderophores production, was selected for further studies. Siderophores produced by the strain SD12 was identified as hydroxymate type. Partial purification was carriedout by ammonium sulphate precipitation and dialysis. The molecular weight of partially purified siderophores was found to be 80KDa and it showed good antifungal activity against Fusarium solani, Aspergillus niger and Phythium sp. The potential strain was identified as Bacillus sp SD12 based on their phenotypic characteristics. Further purification and characterization of siderophores from strain SD12 pave the way for its utilization in the field of medicine and agriculture.

Isolation and characterization of siderophore from cowpeaRhizobium (peanut isolate)

In an iron-depleted broth culture of cowpeaRhizobium (a peanut isolate), phenolate type of compounds were detected. Chemical characterization showed the presence of 2,3-dihydroxy benzoic acid (DHBA) and 3,4-DHBA in the siderophore extract. Lysine and alanine were identified as conjugated amino acids of the siderophore. Maximum concentration of the siderophore in the culture supernatant was found after 24 h of growth. The compounds in the extracted siderophore induced growth ofRhizobium in a medium containing EDTA. Addition of lysine and alanine in the growth medium (20 mM each) led to a fourfold increase in siderophore production.

Isolation and Characterization of Siderophores from Azospirillum lipoferum D-2

Summary: Azospirillum Lipoferum strain D-2 produces the phenolate siderophores 2,3-dihydroxybenzoic acid, 3,5-dihydroxy benzoic acid and salicylic acid under iron-starved conditions. Lysine and leucine were identified as the amino acid conjugates of the siderophores. The concentration of siderophores in the culture supernatant was maximal after 20 h growth. Iron-binding proteins were present in membranes of cultures grown under iron starvation. Iron uptake was enhanced in the presence of each of the siderophores.