Extracellular Biosynthesis of Silver Nanoparticles Using Fungi and Their Antibacterial Activity

Abstract

Silver nanoparticles have particular properties that contribute to their very promising applications, novel in various fields of science, such as the development of biosensors, the diagnosis and treatment of cancer, the controlled release of drugs and the antimicrobial potential. The biological synthesis of nanoparticles is of great interest over other physical and chemical methods because the use of toxic chemicals and drastic reaction conditions are avoided. The extracellular biosynthesis using fungi could also make downstream processing much easier than the intracellular biosynthesis. One of the main applications of silver nanoparticles is their antimicrobial activity. Several studies have demonstrated the bactericidal properties of silver nanoparticles are different from silver ions, and that they are strongly influenced by their shape, size, concentration and colloidal state. In the present work, the ability of fungal strains from Uruguay to synthesize silver nanoparticles was studied. Eight fungi were able to synthesize nanoparticles. An extensive physicochemical characterization of the nanoparticles was carried out including ultraviolet-visible spectroscopy, transmission electron microscopy, dynamic light scattering, zeta-potential and gel electrophoretic mobility. According to the characterization and colloidal stability results, nanoparticles from three fungi were selected for antimicrobial activity assays. All nanoparticles were able to inhibit Escherichia coli growth, demonstrating their potential as effective antibacterial agent for use in biomedical applications.

Biofilm Eradication Using Biogenic Silver Nanoparticles

“…Fermentation was carried out at 28 • C, with agitation on an orbital shaker operating at 150 rpm for 72 h. The biomass from cultures was harvested by filtration and then washed extensively with sterilized distilled water to remove any remaining media components. Then, synthesis of silver nanoparticles was carried out as described in Sanguiñedo et al [7]. Wet fungal mycelia were suspended in sterilized distilled water (0.1 g/mL) and incubated with agitation on an orbital shaker operating at 150 rpm.…”

Biogenic Silver Nanoparticles Can Control Toxoplasma gondii Infection in Both Human Trophoblast Cells and Villous Explants

“…The main characteristics of NPs are low toxicity, modulation of pharmacokinetics, increased bioavailability, and the possibility of transporting pharmacological components, which also allows the drug to be delivered directly to the specific target ( Khalil et al, 2013 ; Torres-Santiago et al, 2016 ). Nanoparticles with silver inserts in their structure, called silver nanoparticles (AgNp), are used for health applications because they have antimicrobial and anti-inflammatory activities ( Shrivastava et al, 2007 ; Adair, 2009 ; Pourali and Yahyaei, 2016 ; Scandorieiro et al, 2016 ) described in Gram-negative and Gram-positive bacteria, including multidrug-resistant strains ( Shrivastava et al, 2007 ; Durán et al, 2016 ; Scandorieiro et al, 2016 ), protozoa as Leishmania ( Allahverdiyev et al, 2011 ; Fanti et al, 2018 ; Isaac-Márquez et al, 2018 ), some virus ( Park et al, 2018 ; Sharma et al, 2019 ), and filamentous fungi ( Sanguiñedo et al, 2018 ). In addition, AgNp is able to accumulate in tissues, probably reaching cysts of T. gondii ( Adeyemi and Sulaiman, 2015 ).…”

Extracellular synthesis of silver nanoparticles using entomopathogenic fungus: characterization and antibacterial potential

“…The term "nano" is derived from a Greek word which means "dwarf " [1,2]. Synthesis of nanoparticles has gained attention due to their applications in multiple fields such as antifungal agents, antibacterial agents, biosensor, bioremediation, anticancer, drug delivery, etc.…”