Siderophore production by marine-derived fungi (original) (raw)
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Siderophore Production by Rhizosphere Inhabiting Bacteria and Fungi
J. Plant Production, 2018
The production of siderophores is greater in rhizosphere inhabiting fungi and bacteria. The present work was designed to isolate the rhizosphere inhabiting bacteria and fungi from the rhizosphere of Phaseolus Vulgaris, Pisum sativum, Vicia faba and Alfa alfa. The obtained isolates has been screened for siderophores production using Chrome Azurol Sulfonate assay (CAS). The highest siderophore producer bacterium and fungus has been molecularly identified as Bacillus MG214652 and Aspergillus niger MH844535 respectively. They were able to produce 70.4% and 87% units of siderophore respectively. Bacillus MG214652 siderophores was characterized as catecholate type with maximum absorbance at 495 nm. Aspergillus niger MH844535 siderophore was characterized as hydroxymate type with maximum absorbance at 450 nm.
Selection and Characterization of Rhizosphere Fungi Producing Siderophore
International Journal of Current Microbiology and Applied Sciences, 2019
is less soluble. As a result, they are difficult to be used by organisms. They are different from some microorganisms like bacteria (Arora, 2017; Patil 2014, Chakraborty, 2014), yeast (Ghosh, 2015) and fungi (Ghosh, 2017; Usha, 2013) that can secrete secondary metabolite siderophore with less iron compound (Hussein, 2019; Prema, 2013). Some fungi producing siderophore are Trichoderma harzianum, T. viride, T. asperellum (Ghosh, 2017), Aspergillusniger and A. flavus (Usha, 2013).
Fungal siderophores: structures, functions and applications
Mycological Research, 2002
Siderophores are low molecular weight, iron-chelating ligands produced by nearly all microorganisms. Fungi synthesize a wide range of hydroxamate siderophores. This review considers the chemical and biological aspects of these siderophores, their distribution amongst fungal genera and their possible applications. Siderophores function primarily as iron transport compounds. Expression of siderophore biosynthesis and the uptake systems is regulated by internal iron concentrations. Transport of siderophores is an energy-dependent process and is stereoselective, depending on recognition of the metal ion coordination geometry. In addition to transporting iron, siderophores have other functions and effects, including enhancing pathogenicity, acting as intracellular iron storage compounds and suppressing growth of other microorganisms. Siderophores can complex other metals apart from iron, in particular the actinides. Because of their metal-binding ability there are potential applications for siderophores in medicine, reprocessing of nuclear fuel, remediation of metalcontaminated sites and the treatment of industrial waste.
Applied Biochemistry and Biotechnology, 2004
A marine isolate of fluorescent Pseudomonas sp. having the ability to produce the pyoverdine type of siderophores under low iron stress (up to 10 µM iron in the succinate medium) was identified as Pseudomonas aeruginosa by using BIOLOG Breathprint and siderotyping. Pyoverdine production was optimum at 0.2% (w/v) succinate, pH 6.0, in an iron-deficient medium. Studies carried out in vitro revealed that purified siderophores and Pseudomonas culture have good antifungal activity against the plant deleterious fungi, namely, Aspergillus niger, Aspergillus flavus, Aspergillus oryzae, Fusarium oxysporum, and Sclerotium rolfsii. Siderophore-based maximum inhibition was observed against A. niger. These in vitro antagonistic actions of marine Pseudomonas against phytopathogens suggest the potential of the organism to serve as a biocontrol agent.
Marin e-derived Fungal Siderophores: A Perception
2016
Siderophores play crucial role in biogeochemical cycle in terrestrial as well as marine environment. Siderophores of bacteria from marine habitats have been extensively studied, however, comparatively less information is available on their fungal counter parts. This review focuses on siderophores of marine-derived fungi, molecular mechanism of siderophore biosynthesis and their uptake. Their chemical nature and applications are also discussed. Data so far available on marine fungal siderophores are found to be very interesting. Though less explored, the information available reveals novelty in chemical nature of siderophores of marine-derived fungi, i.e. occurrence of catecholates in fungi and carboxylates in nonmucoraceous fungi, which is the first-ever report. Further investigations on marine-derived fungal siderophores would be an interesting area of research.
Biosynthesis Pathways, Transport Mechanisms and Biotechnological Applications of Fungal Siderophores
Journal of Fungi, 2022
Iron (Fe) is the fourth most abundant element on earth and represents an essential nutrient for life. As a fundamental mineral element for cell growth and development, iron is available for uptake as ferric ions, which are usually oxidized into complex oxyhydroxide polymers, insoluble under aerobic conditions. In these conditions, the bioavailability of iron is dramatically reduced. As a result, microorganisms face problems of iron acquisition, especially under low concentrations of this element. However, some microbes have evolved mechanisms for obtaining ferric irons from the extracellular medium or environment by forming small molecules often regarded as siderophores. Siderophores are high affinity iron-binding molecules produced by a repertoire of proteins found in the cytoplasm of cyanobacteria, bacteria, fungi, and plants. Common groups of siderophores include hydroxamates, catecholates, carboxylates, and hydroximates. The hydroxamate siderophores are commonly synthesized by fungi. L-ornithine is a biosynthetic precursor of siderophores, which is synthesized from multimodular large enzyme complexes through non-ribosomal peptide synthetases (NRPSs), while siderophore-Fe chelators cell wall mannoproteins (FIT1, FIT2, and FIT3) help the retention of siderophores. S. cerevisiae, for example, can express these proteins in two genetically separate systems (reductive and nonreductive) in the plasma membrane. These proteins can convert Fe (III) into Fe (II) by a ferrous-specific metalloreductase enzyme complex and flavin reductases (FREs). However, regulation of the siderophore through Fur Box protein on the DNA promoter region and its activation or repression depend primarily on the Fe availability in the external medium. Siderophores are essential due to their wide range of applications in biotechnology, medicine, bioremediation of heavy metal polluted environments, biocontrol of plant pathogens, and plant growth enhancement.
Siderophore in fungal physiology and virulence
Journal of Pharmacognosy and Phytochemistry, 2017
The iron plays free catalytic role in various vital cellular reactions and is not freely available in the environment due to host sequestration Maintaining the appropriate balance of iron between deficiency and toxicity requires fixed tuned-control system for iron uptake and storage. Most fungi express specific mechanism for acquisition of iron from the hosts they infect for their own survival. Siderophores, a low molecular weight iron chelator has the ability to form very stable and soluble complexes with iron. High affinity iron uptake systems such as siderophores mediated iron uptake and reductive iron assimilation (RIA) enable fungi to acquire limited iron from plant and animal host. Regulating the iron uptake is crucial to maintain iron homeostasis, a state necessary to avoid iron toxicity from iron abundance and simultaneously supply iron required to meet biochemical demand. Fungal cell used two different strategies to regulate iron acquisition that are activation during iron ...
Applied Microbiology and Biotechnology, 2003
To acquire iron, all species have to overcome the problems of iron insolubility and toxicity. In response to low iron availability in the environment, most fungi excrete ferric iron-specific chelators-siderophores-to mobilize this metal. Siderophore-bound iron is subsequently utilized via the reductive iron assimilatory system or uptake of the siderophore-iron complex. Furthermore, most fungi possess intracellular siderophores as iron storage compounds. Molecular analysis of siderophore biosynthesis was initiated by pioneering studies on the basidiomycete Ustilago maydis, and has progressed recently by characterization of the relevant structural and regulatory genes in the ascomycetes Aspergillus nidulans and Neurospora crassa. In addition, significant advances in the understanding of utilization of siderophore-bound iron have been made recently in the yeasts Saccharomyces cerevisiae and Candida albicans as well as in the filamentous fungus A. nidulans. The present review summarizes molecular details of fungal siderophore biosynthesis and uptake, and the regulatory mechanisms involved in control of the corresponding genes.
Growth and siderophore production of under iron-limited conditions
Microbiological Research, 2005
In this study, the production of siderophores by Xylella fastidiosa from the citrus bacteria isolate 31b9a5c (FAPESP -ONSA, Brazil) was investigated. The preliminary evidence supporting the existence of siderophore in X. fastidiosa was found during the evaluation of sequencing data generated in our lab using the BLAST-X tool, which indicated putative open reading frames (ORFs) associated with iron-binding proteins.
Role and Applications of Microbial Siderophores in the Environment
Ecology, Environment and Conservation, 2023
Siderophores are the low-molecular weight secondary metabolites which have a strong preference for ferric iron and are generated by bacteria when they are exposed to iron stress. Iron is a vital nutrient which is required for the various cellular processes such as electron transport but due to aerobic conditions most of the iron becomes unavailable as surface iron get oxidized into oxyhydroxide polymers and free iron get reduced. Siderophores have clinical, environmental as well as agricultural applications. Clinical applications involve anticancer activity, anti-malarial activity and also help to remove transuranic elements and in agriculture, various types of siderophores help in the promoting the growth of some plant and enhance the uptake of Fe which leads to increase the plant yield and also protect plants from pathogens. Environmental applications involve the binding of the toxic metals such as Pb 2+ , Cd 2+ , Hg 2+ etc, with siderophores which helps in heavy metal bioremediation. The purpose of this review is to explore about siderophores, their varieties, and their uses.