Biosynthesis and Characterization of Silver Nanoparticles Produced by Phormidium ambiguum and Desertifilum tharense Cyanobacteria

Abstract

The world faces a challenge with the pervasion of multidrug-resistant bacteria that encourages scientists to develop and discover alternative, ecofriendly, and easy-to-produce new antibacterial agents. Our work is part of the greater effort of scientists around the world to achieve this goal by the biological synthesis of silver nanoparticles using cyanobacterial extracellular and intracellular components as nonchemical reducing agents. Two Egyptian cyanobacteria were isolated and identified according to 16S rRNA gene sequencing as Phormidium ambiguum and a novel species Desertifilum tharense. The sequences were deposited with accession numbers MW762709 and MW762710 for Desertifilum tharense and Phormidium ambiguum, respectively, in the GenBank. The results of UV-Vis analysis showed promising extracellular Ag-NPs synthesis by Desertifilum tharense and Phormidium ambiguum under light conditions. Therefore, these Ag-NPs were characterized and evaluated for antibacterial and antioxidant activity. TEM and SEM analyses revealed the spherical crystals with face-centered cubic structures and size range of 6.24–11.4 nm and 6.46–12.2 nm for Ag-NPs of Desertifilum tharense and Phormidium ambiguum, respectively. XRD and EDX results confirmed the successful synthesis of Ag-NPs in their oxide form or chloride form. The FTIR spectrum data confirmed the presence of hydroxyl and amide groups. Desertifilum tharense Ag-NPs displayed the largest inhibition zone that ranged from 9 mm against Micrococcus luteus ATCC 10240 to 25 mm against methicillin-resistant Staphylococcus aureus (MRSA) ATCC 43300. For Phormidium ambiguum Ag-NPs, the inhibition zone diameter was in the range of 9 mm to 18 mm. The biosynthesized Ag-NPs significantly inhibited the growth of medically important resistance-pathogenic Gram-positive and Gram-negative bacteria. The Ag-NPs of Phormidium ambiguum exhibited the highest scavenging activity of 48.7% when compared with that of Desertifilum tharense, which displayed 43.753%.

Green Synthesis of Hexagonal Silver Nanoparticles Using a Novel Microalgae Coelastrella aeroterrestrica Strain BA_Chlo4 and Resulting Anticancer, Antibacterial, and Antioxidant Activities

“…The authors reported that the small size and crystalline nature of Ag-NPs was a significant factor in enhancing the antioxidant activity of NPs. Hanna et al screened the antioxidant potential of Ag-NPs produced by Desertifilum tharense and Phormidium ambiguum (D-Ag-NPs and P-Ag-NPs, respectively) and algal extracts using DPPH assays [ 43 ]. D-Ag-NPs and P-Ag-NPs exhibited a scavenging activity of 43.75% and 48.7%, respectively, while that of D. tharense and P. ambiguum was 36.14% and 33.9%, respectively.…”

“…The antioxidant activity of C@Ag-NPs and aqueous algal extract was examined using a DPPH assay according to the method described by Hanna et al [ 43 ]. Briefly, 1 mg/mL C@Ag-NPs was sonicated for 10 min and then various concentrations of NPs (1000, 500, 250, 125, 62.5, 31.25, 15.6, 7.8, 3.9, and 1.95 µg/mL) were prepared.…”

Taxonomic Enumeration of Subaerial Cyanobacterial Flora of Similipal Biosphere Reserve, Odisha, India

“…A phase-contrast microscope and a digital camera were used to take microphotographs of each species (Olympus SC180). Morphological identification: By the following existing literature, the morphological traits of specimens of cyanobacterial species were identified and enumerated (Behera et al, 2020;Behera et al, 2021;Bhakta et al, 2015;Bhakta et al, 2014;Das and Adhikary, 2014;Dash et al, 2020;Dash et al, 2021;Desikachary, 1959;Hanna et al, 2022;Hindák, 1977;Jena et al, 2006;Khaybullina et al, 2010;Kim and Lee, 2014;Komárek, 2005;Komárek and Anagnostidis, 1999;Komárek et al, 1983;Komárek and Johansen, 2015;Komárek et al, 2011;Komárek et al, 2013;Komárková et al, 2010;Lopez-Bautista et al, 2007;Loza et al, 2013;Maharana et al, 2019;Mahendra Perumal and Anand, 2009;Nakano and Isagi, 1987;Škaloud, 2008, 2010;Pradhan et al, 2021a;Pradhan et al, 2021b;Stace et al 2005;Vijayan and Ray, 2015;West et al, 1912).…”

A Review of the Application of Nanoparticles Biosynthesized by Microalgae and Cyanobacteria in Medical and Veterinary Sciences

“…The researchers suggest nitrate reductase stimulates the enzyme synthesizing nanosilver particles in Bacillus licheniformis. Other studies have shown that nitrogenases (nitrogen-fixing enzymes) can convert gold ions into gold nanoparticles as powerful reducing agents (Hanna et al, 2022).…”

“…Cyanobacteria are decent biological systems for the synthesis of intracellular and extracellular ATP. Spirulina can synthesize monometallic and bimetal nanoparticles of gold, silver, and gold-silver extracellularly (Hanna et al, 2022).…”