Biological Sciences
Siderophores
Siderophores are small molecules produced by microorganisms to scavenge iron from their environment. They have a high affinity for iron and can bind to it even when it is present in very low concentrations. Siderophores play an important role in microbial growth and survival, and have potential applications in medicine and biotechnology.
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11 Key excerpts on "Siderophores"
eBook - ePub- (Author)
- 2018(Publication Date)
- Elsevier(Publisher)
Chapter 5 Siderophores: Amazing Metabolites of Microorganisms Tomáš Řezanka 1 ; Andrea Palyzová; Helena Faltýsková; Karel Sigler Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic 1 Corresponding author: email address: [email protected] Abstract Siderophores are low-molecular-chelating chemical compounds specific to iron ions that are produced by bacteria, fungi, cyanobacteria, and plants (phytoSiderophores) growing at a low-Fe 3 + concentration. The role of these compounds is to obtain iron from the environment and create a soluble complex that is needed to make it available to microbial cells. Siderophores formed by bacteria contribute to their pathogenicity since bacteria require iron for their growth and metabolism and remove it from the host organism during infection. They play an important role as growth-promoting factors in unculturable microorganisms. In agriculture, Siderophores support the growth of many plants and increase their production by increasing the availability of Fe 3 + to plants. Siderophores can also be used as potential biopesticides against dangerous phytopathogens so that they can replace pesticides obtained by organic synthesis. They can also be used for heavy metal bioremediation of soils and as biosensors for detecting contaminated environments. In medicine, Siderophores can be used to create complexes with antibiotics, thereby increasing the strength of their attack on bacteria resistant to antibiotics. Medical applications of Siderophores include antimalarial activity and treatment of sickle cell anemia. In this chapter we focus on physicochemical methods for detecting the presence of Siderophores in microorganisms and the use of these methods for the detection and characterization of microorganisms producing Siderophores
- Bernard R Glick, G Holguin, C L Patten(Authors)
- 1999(Publication Date)
- ICP(Publisher)
Chapter 3 Siderophores Iron is essential for life. With rare exceptions, living organisms, whether animals, plants or microbes, require iron as a component of proteins involved in important processes such as respiration, photosynthesis and nitrogen fixation. Ironically, despite the abundance of this element on the earth's surface, soil organisms such as plants and microbes have difficulty obtaining enough iron to support their growth because the iron in soil is largely present as insoluble, ferric hydroxides, which cannot be readily transported into cells. To solve the iron problem, bacteria, fungi and some plants secrete small, specialized iron-binding molecules called Siderophores into the soil to scavenge iron. Once bound, the now soluble iron-siderophore complex is taken up by specific receptors on the soil exposed surfaces of these organisms; following reduction to the ferrous state, the iron is released from the siderophore. The ability to take up and utilize the iron-bound Siderophores secreted by other organisms further enhances survival and growth as not only does this increase the availability of usable iron, but also enables such opportunistic organisms to effectively compete with other soil organisms for iron. On the other hand, survival of organisms that either do not produce Siderophores or produce Siderophores with a relatively low affinity for iron, and that cannot capture the iron-siderophore complexes of other organisms is diminished further because any iron that was available will be further depleted from the soil by their better adapted competitors. The promotion of plant growth by siderophore-producing bacteria is believed to occur by one or both of these mechanisms, that is, by directly supplying iron for plant utilization and/or by removing iron from the environment of phytopathogens thereby reducing their competitiveness.
eBook - ePubClimate Change and Microbial Diversity
Advances and Challenges
- Suhaib A. Bandh, Javid A. Parray, Nowsheen Shameem(Authors)
- 2022(Publication Date)
- Apple Academic Press(Publisher)
−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 weight 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.7.1 Siderophores
Fe+2 is an essential cofactor for conducting various metabolic activities. It also plays a vital role by regulating the biosynthesis of porphyrins, vitamins, antibiotics, toxins, cytochromes, pigments, aromatic compounds, nucleic acid synthesis, and microbial biofilm formation by regulating the surface motility of microorganism (Messenger and Barclay, 1983 ; Glick et al., 2010 ; Cai et al., 2010 ). At physiological pH (7.35-7.40), ferrous form of iron is soluble, while the ferric form is insoluble (Bou-Abdallah, 2010 ). It is reported that at this condition, the concentrations of dissolved ferrous iron is found to be approximately 10−10 -10−9 M in precipitate form, whereas the required level of ferrous iron by living organisms is around 10−7 -10−5 M (Poole and McKay, 2003 ; Matsumoto et al., 2004
eBook - PDFThe Rhizosphere
Biochemistry and Organic Substances at the Soil-Plant Interface, Second Edition
- Roberto Pinton, Zeno Varanini, Paolo Nannipieri, Roberto Pinton, Zeno Varanini, Paolo Nannipieri(Authors)
- 2007(Publication Date)
- CRC Press(Publisher)
187 B. Analysis of Fe Stress Effects on Microbial Community Structures in the Rhizosphere of Barley ......................................................................................... 187 VIII. Functions of Siderophores in Rhizosphere Competence .................................................... 189 IX. Role of Siderophores in Biocontrol of Plant Pathogens ..................................................... 190 X. Function of Siderophores in Nitrogen Fixation .................................................................. 192 XI. Summary .............................................................................................................................. 193 References ...................................................................................................................................... 194 I. INTRODUCTION Siderophores are iron chelating agents that are secreted by microorganisms and graminaceous plants in response to iron deficiency. Given the essential requirement for iron by almost all living organ-isms, these compounds are important not only for iron nutrition but are also speculated to function in the ecology of microorganisms in the plant rhizosphere [1]. Siderophores have been studied for their importance in plant disease suppression by mediating nutritional competition for iron [2,3], and they contribute directly to the rhizosphere competence of root-colonizing bacteria [4,5]. In research on plant ecology, Siderophores have been investigated in relation to calcicole and calcifuge plant species and as one of the factors that may explain the distribution of various plant species in different soils [6]. Still other research has focused on plant microbe systems for phytoremediation of heavy metals, in which Siderophores and phytoSiderophores facilitate heavy metal uptake and food chain transfer of metals [7–11].
- V. Rajesh Kannan, Kubilay Kurtulus Bastas(Authors)
- 2015(Publication Date)
- CRC Press(Publisher)
The stability of siderophore-iron complexes is an important factor for the siderophone efficiency. Siderophore application is widespread in various areas of medicine and environmental microbiology, but many scientific challenges remain for research on biocontrol pseudomonads. It will be important to exploit molecular techniques to study the genome expression of plant beneficial and plant pathogenic microorganisms in situ, and to obtain a fuller picture of the mechanisms behind the suppression by siderophore production of the growth of plant pathogens (phytopathogens). In the future, novel Siderophores can be biosynthesized and used for the biocontrol of bacterial as well as fungal pathogens. It has also been reported that survival of specific proteins (e.g., FeoB) in some phytopathogens is required for X. oryzae pv. oryzae to grow inside the rice plant and induce pathogenicity. Therefore, when a specific protein necessary to produce pathogenicity, it can be used as a target for developing new molecules that can, in turn, be applied in fields against various diseases that affect economically valuable plants. Acknowledgments The authors express their deep appreciation to the University Grant Commission, New Delhi, for financial support by the UGC-Major Research Project (MRP No: 39-214/2010). The central facilities of the UGC-CEGS, DST-PURSE Programme, the DBT-IPLS at MKU, and the coordinator at NRCBS, School of Biological Sciences, Madurai Kamaraj University, Madurai, Tamil Nadu, India are also gratefully acknowledged. References Abeer, H., Makhlouf, I., Hamedo, H.A. 2013. Suppression of bacterial wilt disease of tomato plants using some bacterial strains. Life Science 10(3): 1732–1741. Agrios, G.N. 2005. Plant Pathology, 5th Edn. San Diego, CA: Elsevier Academic Press. Albrecht-Gary, A.M., Crumbliss, A.L. 1998. Coordination chemistry of Siderophores: Thermodynamics and kinetics of iron chelation and release. Metal Ions Biol
- Swati Tyagi, Robin Kumar, Baljeet Saharan, Ashok Kumar Nadda, Swati Tyagi, Robin Kumar, Baljeet Saharan, Ashok Kumar Nadda(Authors)
- 2021(Publication Date)
- CRC Press(Publisher)
Siderophores are a certain class of low molecular weight peptides synthesized in various bacteria, especially in PGPR, that could provide an alternative method for remediation of soil affected by harmful metals, and it can also act as a chelator for the various metal ions (Jing et al. 2007). Recently, studies have been conducted on these low molecular weight (≤10 kDa) molecules, known as Siderophores, that form the important part of secretions from various plants and microbial sources into the root zone of the plant (Hider and Kong 2010; Ahmed and Holmstrom 2014; Johnstone and Nolana 2015). In comparison to plant-based Siderophores, which are produced in lower quantity, Siderophores from bacteria have high iron-binding capacity (Kraemer 2004; Kraeme et al. 2006; Glick 2012). Different biochemical properties, such as pH, complex forming sites, redox potential, etc., directly affect the metal-chelating potential of such compounds (Akafia et al. 2014). These peptides scavenge for metal ions, especially for iron, in the root zone (Aznar and Dellagi 2015). Other important characteristics of Siderophores include acting against various kinds of harmful bacteria, through the production of sideromycins (Braun et al. 2009). Siderophores also have a high affinity toward metal ions such as vanadium (Vn), molybdenum (Mo), copper (Cu), and zinc (Zn) (Hood and Skaar 2012). Zincophores are Zn-binding Siderophores that are synthesized in some bacteria (Prentice et al. 2007), including Pseudomonas, which have a high manganese-binding ability (Harrington et al. 2012; Duckworth et al. 2014). Elements such as Mo and Vn also form complexes with other types of Siderophores (Deicke et al. 2013). Similarly, Cu containing complex compounds include methanobactin, yersiniabactin, and coproporphyrin (Chaturvedi et al. 2014). Yersiniabactin, enterobactin, and aerobactin can synthesize gold (Au) nanoparticles (Wyatt et al. 2014)
- Larry Barton(Author)
- 2012(Publication Date)
- Academic Press(Publisher)
PARTI PRODUCTION AND CHARACTERISTICS OF METAL CHELATORS This page intentionally left blank 1 CLASSES OF MICROBIAL Siderophores MONICA HÖFTE Laboratory of Phytopathology and Phytovirology State University of Gent Gent, Belgium I. Introduction II. Classes of Microbial Siderophores A. Bacterial Siderophores B. Fungal Siderophores III. Ecological Significance of Bacterial and Fungal Siderophores References I. INTRODUCTION S.derophores are ferric ion-specific l l g a„ds of ,o„ nroiecuiar weigh, (M r < 1500). Their biosynthesis is regulated carefully by iron; their function is to supply iron to the cell. In addition to the Siderophores themselves, membrane receptors are produced for the uptake of the ferric Siderophores. With only a few exceptions, all aerobic and facul-tative anaerobic microorganisms that have been examined critically thus far produce Siderophores. T h e majority of the Siderophores can be classified as either hydroxamates or phenol—catecholates, although sid-erophores that contain neither of these ligand systems have been de-scribed. Since the reviews by Neilands (1981) and Hider (1984), in which classes of Siderophores are discussed, were written, new methods to detect Siderophores have been developed and many new structures have been described. This review provides an overview of the various classes of microbial Siderophores that have been described to date. Emphasis Iron Chelation in Plants and Soil Microorganisms Copyright © 1993 by Academic Press, Inc. All rights of reproduction in any form reserved. 3 4 Part 1 Production and Characteristics of Metal Chelators is placed on siderophore production by plant-associated bacteria and fungi, although siderophore production by other microorganisms is mentioned also. A comprehensive list of Siderophores is given by Winkelmann (1986). A list of Siderophores produced by plants and plant-associated microorganisms is given in an excellent review by Loper and Buyer (1991).
eBook - PDF- Jillian F. Banfield, Javiera Cervini-Silva, Kenneth Nealson(Authors)
- 2018(Publication Date)
- De Gruyter(Publisher)
Not only could the amphiphilic character of the Siderophores function to keep Siderophores in close contact with the bacteria (Xu et al. 2002), but importantly this amphiphilicity will increase surface reactivity. The enhanced surface reactivity of photo-reactive Siderophores on iron-containing particles may well further promote dissolution of iron minerals; these investigations are in progress. The aquachelins, marinobactin and amphibactins are all produced as suites of Siderophores. The amphiphilic Siderophores with shorter fatty acids (e.g., C12) partition into vesicle membranes far less than the longer chained fatty acids (C18). The decreased partitioning however increases the availability of particle interactions. 76 Kraemer, Butler, Borer, Cervini-Silva CONCLUSIONS Understanding the cycling of iron in marine systems and how it relates to biological nutrient acquisition processes remains a challenge for biogeochemical research. This challenge has been met with impressive vigor and success, considering the difficulty to measure iron concentrations, solubilities, and speciation at sub-nanomolar levels. However, some important information is missing. For example, while it is well known that iron in marine surface waters is bound to strongly complexing ligands, their characterization and identification is difficult. However, indirect evidence suggests that biogenic ligands including microbial Siderophores play an important role in marine iron speciation. A further challenge will be the understanding of trace nutrient cycling and the indications of trace nutrient limitation in the geological record, considering the potential importance of iron and other trace nutrients for the global climate and for biological evolution in the past.
eBook - ePubCyanobacteria
From Basic Science to Applications
- A.K. Mishra, D.N. Tiwari, A.N. Rai(Authors)
- 2018(Publication Date)
- Academic Press(Publisher)
− 1 . Here, it was found that the cyanobacterium can tolerate 7.5 and 5 μM cadmium under iron replete and deplete conditions but produces Siderophores only when iron is eliminated from the growth medium. However, the presence of cadmium had only a negligible effect on siderophore production.11 Biomedical Significance of Siderophores
Nowadays, the nonspecific adsorption of biomolecules (proteins and carbohydrates) and biological organisms (bacteria and fungi) to the biomedical devices and biosensors is a serious problem because it causes nosocomial infections and leads to pathogen-mediated death in hospitals. This process of adsorption is called biofouling. To circumvent this problem, a number of antifouling substances, i.e., polyethylene glycol (PEG) (Lee et al., 1989 ; Desai and Hubbell, 1991 ; Prime and Whitesides, 1991 ), polyglycerol (Siegers et al., 2004 ), peptoids (Statz et al., 2005 ), and poly-2-methyl-2-oxazoline (Konradi et al., 2008 ) have so far been developed. However, formation of an antifouling surface using the cyanobacterial siderophore anachelin was reported by Gademann et al. (2009) . He showed that anachelin, due to the presence of a catechol group, can immobilize PEG on titanium oxide (TiO2 ) and leads to the formation of a protein-resistant surface.12 Conclusions
Cyanobacteria produce hydroxamate and catecholate-type Siderophores through NRPS-dependent and NRPS-independent pathways and these Siderophores play a central role in iron acquisition from the environment. The MFS-type and TolC-like proteins located in the plasma membrane and outer membrane, respectively, execute the process of siderophore secretion whereas the Exb/TonB system generally accomplishes siderophore-mediated iron uptake. The cyanobacterial Siderophores having photochemical reactivity increase the iron bioavailability in the nature by transferring charge to and subsequently reducing the ferric iron (Fe3 + ) to the ferrous iron (Fe2 +
eBook - ePub- Gunther Winkelmann(Author)
- 2020(Publication Date)
- CRC Press(Publisher)
3Enzymology of Siderophore Biosynthesis in Fungi
Hans Jürgen Plattner and Hans Diekmann Institute of Microbiology, University of Hannover, Hannover, GermanyI. Introduction
In low iron environments, most fungi secrete iron chelating compounds known as Siderophores. The biosynthesis and secretion of desferriSiderophores as well as the uptake of siderophore iron (III) complex is heavily increased during growth under iron deprivation.Most known fungal Siderophores are of the hydroxamate type and derivatives of l -ornithine. Their structures do not vary as widely as those from bacteria (Winkelmann, 1986, 1991). At first glance, the enzymology of fungal siderophore biosynthesis might seem to be quite simple. Emery (1974) has reviewed siderophore biosynthesis, but at that time little was known on microbial N -hydroxylation and nonribosomal peptide synthesis. Progress was enhanced by the fact that plasmid-coded aerobactin was shown to be a virulence factor of some bacteria (Williams, 1979; Waters and Crosa, 1991). Also, the interest in Siderophores and their biosynthesis was stimulated by reports on many other biological activities, like induction of spore germination (Horowitz et al., 1976; Matzanke et al., 1987), enhanced iron uptake of mycorrhizal fungi in roots of vascular plants (Haselwandter et al., 1992), virulence of bacterial plant pathogens (Persmark et al., 1992), and infections caused by the opportunistic pathogen Candida albicans (Sweet and Douglas, 1991).Despite the progress that has been made during the last 15 years, we are far from a complete understanding of all aspects of fungal siderophore biosynthesis. This review will not only report on results but likewise focus on questions to be answered. Progress will only be made if our knowledge of the molecular genetics of siderophore biosynthesis in fungi is comparable to what is known about bacteria. The study of fur
eBook - ePub- Gunther Winkelmann(Author)
- 2022(Publication Date)
- CRC Press(Publisher)
et al., 1993).Despite the fact that fungi are ubiquitous siderophore producers, to date there is only limited understanding about the relationship between fungal high-affinity iron assimilation systems and virulence. This can be attributed to difficulties of isolating relevant mutants and inadequate development of fungal molecular genetic tools. The best studied fungal siderophore system is in the plant pathogen U. maydis (Mei and Leong, 1994 ). By using siderophore non-producing mutants, Mei et al., (1993) found that Siderophores were not required for the fungus to cause corn smut. This result does not imply that Siderophores are not required for other stage (s) of the fungal life cycle, for example, spore viability during overwintering in soil.Hydroxamate siderophore production by opportunistic and systemic fungal pathogens, such as Absidia corymbifera, Aspergillus niger, Rhizopus arrbizopus, Blastomyces dermatitidis, Histoplasma capsulatum, Sporothrix schenickii, Candida albicans, and Trichophyton mentagrophytes has been reported (Holzberg and Artis, 1983), but little is known about the role of iron in human fungal infection. As mentioned above, in C. neoformans melanin and iron may play an important role in providing a shield against oxidants produced by the immune system. Moreover, production of adhesins in C. albicans is enhanced during iron limitation (Douglas, 1995 ). Some indirect evidence suggests that Siderophores may function as virulence factors by facilitating growth under conditions of limited iron availability. For example, exogenous Siderophores are known to exacerbate infection by Rhizopus, Aspergillus and Cryptococcus infection in Guinea pig (Boelaert et al.
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