Intracellular Siderophore Detection in an Egyptian, Cobalt-Treated F. solani Isolate Using SEM-EDX with Reference to its Tolerance

Abstract

A b s t r a c tAn Egyptian, plant pathogenic Fusarium solani isolate was grown on cobalt concentrations of 0, 50, 200, 500, 800, and 1000 ppm. The isolate survived concentrations up to 800 ppm, however failed to grow at 1000 ppm. Morphology and elemental analysis of the isolate under the investigated Co concentrations were studied using Scanning electron microscopy (SEM) and energy dispersive X-ray microanalysis (EDX). The isolate reserved its morphology up to a concentration of 200 ppm. Morphological distortions were dramatic at 500 and 800 ppm. EDX detected Co uptake through the hyphae, microconidia, macroconidia, and chlamydospores. Iron, calcium, and potassium were also detected. EDX results showed a linear relationship between Co% and Fe% up to a concentration of 500 ppm reflecting the possible ability of the isolate to synthesize intracellular siderophores storing iron and their release from the vacuoles. The participation of such siderophores in conferring tolerance against cobalt is discussed. At 800 ppm, the % of Fe was greatly reduced with an accompanying increase in morphological distortions and absence of microconidia. Increasing the implicated cobalt concentrations resulted in increasing the percentages of the chelated cobalt reflecting the possible implication of the cell wall as well as extracellular siderophores in the uptake of cobalt. The current results recommend the absence of cobalt in any control regime taken to combat the investigated F. solani isolate and highlights the accomplishment of biochemical, ultrastructural, and molecular studies on such isolate to approve the production of siderophores and the role of cell wall in cobalt uptake.K e y w o r d s: Fusarium solani, cobalt uptake, cobalt tolerance, siderophores

Tolerance and mycoremediation of silver ions by Fusarium solani

“…Live, dead, pre-treated and immobilized forms of Aspergillus spp., Penicillium sp., Botrytis sp., Trichoderma sp., Saprolegnia sp., Neurospora sp., Termitomyces clypeatus, and Saccharomyces cerevisiaewere applied frequently to remove toxic metal ions (Amirnia et al, 2015;Iram and Abrar, 2015;Mohammadian Fazli et al, 2015;Dhal and Pandey, 2018). Fusarium solani has a fast growth rate, higher capacity of metal ion reduction, nanoparticles formation and higher yield of biomass (Abd EL-Aziz et al, 2015), with higher tolerance to heavy metals like Cd(II), Cr(VI), Ni, Pb, Zn(II), Co(II), and Pb(II) (Vargas-García et al, 2012;El-Sayed, 2014;Rasha, 2017). The objective of this study was to assess the different tolerance mechanisms of F. solani to Ag(I), and to determine the optimum conditions for maximum absorption and transformation of Ag(I) by F. solani.…”

The influence of tin ions on growth and enzymatic activity of entomopathogenic fungi

“…EPF exhibited differential tolerance to the presence of Sn, there were visible differences in development as well as differences in EPF biochemical activity; these demonstrate that Sn exerted a degree of toxicity towards microorganisms. The morphological changes and the colorful reactions that occur when EPF are in contact with Sn 2+ ions may be the result of physiological disturbances; this has been shown in other microorganisms [26,34,35]. The production of organic acid-based pigments (such as salts of oxalic acid and citric acid), in fungal cells or their secretion into the environment could be harnessed to precipitate metal ions; this could be used in mechanical detoxification.…”

“…There are two mechanisms that have been proposed to explain the tolerance of fungi to heavy metals. These include the extracellular sequestration of the metal ions by chelation or cell wall binding and the intracellular and physical sequestration of metals by binding them to proteins or other ligands to prevent the metal ion from damaging the metal sensitive cellular targets [34,35]. Among the tested EPF, the highest tolerance to contact with Sn 2+ was demonstrated by M. robertsii, with an MIC value of 1,000 ppm.…”

Insights into the recent advances in nano-bioremediation of pesticides from the contaminated soil

“…The synthesis of AgNPs from Rhizopus oryzae have several ecological uses like wastewater treatment ( Zhang et al, 2014 ) and adsorption of pesticides ( Das et al, 2012 ). Fungi like Fusarium solani have higher tolerance against few heavy metals like cadmium, nickel and lead, also have better capacity of nanoparticles synthesis ( Rasha, 2017 ). The extremophilic fungi have significant ability and application in nano-bioremediation of heavy metals due to ability to survive in severe conditions, which makes them significant for the purpose of nano-bioremediation ( Bahrulolum et al, 2021 ).…”