Tolerance and mycoremediation of silver ions by Fusarium solani

Abstract

Silver ions discharged from various industries, are potentially toxic to living organisms at low concentrations, thus, there is an increasing need for development of an eco-friendly and cost-effective approach for its bioremediation. Filamentous fungi especially, Fusarium solani displayed a strong resistance to copper and cadmium ions as revealed from our previous study (El-Sayed 2014), however, the mechanisms of silver resistance by this fungus has not been resolved yet. Thus, this study was an extension to our previous work, to elucidate the mechanism of silver ions resistance and biotransformation by F. solani. The growth, bioaccumulation, thiol, total antioxidant, malondialdehyde (MDA), hydrogen peroxide (H 2 O 2 ) contents and polyphenol oxidase (PPO) and catalase (CAT) activities of F. solani in response to silver ions were determined. Production and bioaccumulation of silver nanoparticles was characterized by UV-visible spectroscopy, TEM, and X-ray powder diffraction (XRD). The ultrastructural changes of F. solani induced by Ag(I) was examined by TEM and SEM. Production of oxalic acid by F. solani was increased by about 343.8% in response to 400 mg/l Ag(I), compared to control cultures (without silver ions) as revealed from HPLC analysis. The maximum biosorption levels by the native and alkali-treated biomass were carried out at pH 5.0, initial metal concentration 200 mg/l, biomass 0.5 g/l, temperature 35 C, and contact time 1 h (native biomass) and 3 h (alkali-treated biomass). Fourier transform infrared spectroscopy (FTIR) results revealed that the main functional groups involved on this mycoremediation were C-S stretching, C¼O C¼N, C -H bending, C-N stretching and N-H bending. EDX spectra indicated the involvement of fungal cellular sulfur and phosphorus compounds in Ag(I) binding.

Mycosynthesis of ZnO Nanoparticles Using Trichoderma spp. Isolated from Rhizosphere Soils and Its Synergistic Antibacterial Effect against Xanthomonas oryzae pv. oryzae

“…Fungi have become one of the choices in nanotechnology because of its wide variety of advantages over the bacteria, actinomycetes, plants and other physic-chemical properties. The capability of tolerance and metal bioaccumulation in fungi has made fungi a significant branch in the biosynthesis of nanoparticles [27]. Non-toxic and safe reagents are used in the green synthesis of nanoparticles, which makes them cost effective and environmentally friendly [28].…”

Biosynthesis and Anti-Mycotoxigenic Activity of Zingiber officinale Roscoe-Derived Metal Nanoparticles

“…The SPR bands that observed around ~λ326 nm, corresponding to aromatic amino residues. The metal reducing potency of ginger extract might be due to the presence of ascorbic acid and/or oxalic acid [ 46 ]. The chemical reduction converts Ag + ions to Ag 0 , and evolving the nucleation of NPs, and then the NPs are confined by the layers of ascorbic acid and/or oxalic acid via electrostatic forces of the ginger extract.…”

Bioremediation and tolerance of zinc ions using Fusarium solani

“…Fusarium solani KJ 623702 had been isolated and molecularly identified from our previous work ( El-Sayed, 2014 , El-Sayed and El-Sayed, 2020a , b ). The strain conserved on PDA slants at 4 °C, supplemented with ZnSO 4 .2H 2 O to give final desired concentrations (0, 2000, 4000, 6000, 8000, 9000, 10000, 11000, and 12000 mg/l), then poured to the petri plates.…”

“…During the growth, the white coalescence was notice, suggesting the reduction of Zn(II) and the formation of zinc oxide nanoparticles (ZnONPs). The biomass was separated by centrifugation and dried at 60 °C, the filtrates were utilized for characterization of ZnONPs by UV-Visible spectroscopy, TEM analysis (JEOL TEM-1400), and X-ray powder diffraction (XRD) (Broker D8 Advanced target Cu Koα powder diffractometer (λ = 1.5418 °A) ( El-Sayed and El-Sayed, 2020a , b ). For the TEM analysis, the samples were loaded on carbon-coated grids and dried, a thin film on glass slides was dried at 45 °C and used for XRD.…”

“…For the TEM analysis, the samples were loaded on carbon-coated grids and dried, a thin film on glass slides was dried at 45 °C and used for XRD. The residual Zn(II) was measured with atomic absorption spectrophotometer (Unicam 969) ( El-Sayed and El-Sayed, 2020a , b ). The efficiency of removal (E) determined according to the following equation: E = [(Ci − Cf)/Co] ×100 Where Ci and Cf are initial and residual concentrations of Zn(II) (mg/l), respectively.…”