Optimization of the biological synthesis of silver nanoparticles using Penicillium oxalicum GRS-1 and their antimicrobial effects against common food-borne pathogens

Abstract

Biologically synthesized nanoparticles are gaining importance as they offer several advantages, such as the ease with which they can be scaled up, the cost-effectiveness of the process and the green route of production. In this study, silver (Ag) nanoparticles were biosynthesized using the cellular extract of Penicillium oxalicum GRS-1 and then characterized by ultraviolet visible spectroscopy, X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy. The biosynthesis of nanoparticles was optimized by following the one factor at a time approach, wherein the temperature of 60°C, pH 7.0 and 1.5 mm silver nitrate (AgNO3) concentration were found to be most favorable factors for the production of Ag nanoparticles. Upon statistical optimization, the maximum production of Ag nanoparticles with a concentration of 136 ppm was achieved at pH 7.2, AgNO3 concentration 1.975 mm and 86 h using the crude cellular extract of P. oxalicum GRS-1 having nitrate reductase activity. TEM analysis showed that the Ag nanoparticles were spherical in shape with sizes ranging from 10 to 40 nm. The biosynthesized nanoparticles showed strong antimicrobial activity against the common food-borne, pathogens including Staphylococcus aureus, Escherichia coli and Salmonella typhimurium with respective minimum bactericidal concentrations of 32, 16 and 32 μg/ml.

Synthesis of Silver Nanoparticles Mediated by Fungi: A Review

“…Shahzad et al (2019) evaluated the use of 1, 4, 7, and 10 g quantities of Aspergillus fumigatus BTCB10 biomass, observing greater production, smaller size, and better dispersion of the nanoparticles when the synthesis was based on the use of 7 g of biomass. In the work of Rose et al (2019), employing Penicillium oxalicum , greater nanoparticle production was obtained using a higher biomass concentration, which was attributed to greater release of the nitrate reductase enzyme by the mycelium. Saxena et al (2016) observed higher silver nanoparticle production when the amount of Sclerotinia sclerotiorum biomass was increased.…”

Silver nanoparticles: synthesis, characterisation and biomedical applications

“…Additionally, incubation of Phanerochaete chrysosporium mycelium with silver nitrate solution produced silver nanoparticles [49]. Korbekandi and colleagues showed the bioreductive production of silver nanoparticles by using Fusarium oxysporum [50].…”

Green Synthesis and Antibacterial Activity of HAp@Ag Nanocomposite Using Centella asiatica (L.) Urban Extract and Eggshell

“…These techniques utilize plant extracts, which play a role as effective reducing and stabilizing agents for salt ions to form uniform nanoparticles [ 9 , 10 ]. Recent research has demonstrated that the synthetic process of Ag-NPs using leaf extracts such as Polyalthia longifolia, Geranium (Pelargonium graveolens), Eucalyptus citriodora (neelagiri), Ficus benghalensis (marri), and Penicillium oxalicum can produce NPs with average size from 16 to 58 nm [ 11 – 15 ].…”