Green production of microalgae-based silver chloride nanoparticles with antimicrobial activity against pathogenic bacteria.

Title Green production of microalgae-based silver chloride nanoparticles with antimicrobial activity against pathogenic bacteria.
Authors Vda Silva Ferreira; M.Eugenio ConzFerreira; L.Maurício Lima; S. Frasés; W. de Souza; C. Sant'Anna
Journal Enzyme Microb Technol
DOI 10.1016/j.enzmictec.2016.10.018
Abstract

Silver nanoparticles are powerful antimicrobial agents. Here, the synthesis of silver chloride nanoparticles (AgCl-NPs) was consistently evidenced from a commercially valuable microalgae species, Chlorella vulgaris. Incubation of C. vulgaris conditioned medium with AgNO3 resulted in a medium color change to yellow/brown (with UV-vis absorbance at 415nm), indicative of silver nanoparticle formation. Energy-dispersive X-ray spectroscopy (EDS) of purified nanoparticles confirmed the presence of both silver and chlorine atoms, and X-ray diffraction (XRD) showed the typical pattern of cubic crystalline AgCl-NPs. Transmission electron microscopy (TEM) showed that most particles (65%) were spherical, with average diameter of 9.8±5.7nm. Fourier transform infrared spectroscopy (FTIR) of purified nanoparticle fractions suggested that proteins are the main molecular entities involved in AgCl-NP formation and stabilization. AgCl-NPs (from 10?g/mL) decreased by 98% the growth of Gram-positive Staphylococcus aureus and Gram-negative Klebsiella pneumoniae bacterial pathogens, and had a dose-dependent effect on cell viability, which was measured by automated image-based high content screening (HCS). Ultrastructural analysis of treated bacteria by TEM revealed the abnormal arrangement of the chromosomal DNA. Our findings strongly indicated that the AgCl-NPs from C. vulgaris conditioned medium is a promising 'green' alternative for biomedical application as antimicrobials.

Citation Vda Silva Ferreira; M.Eugenio ConzFerreira; L.Maurício Lima; S. Frasés; W. de Souza; C. Sant'Anna.Green production of microalgae-based silver chloride nanoparticles with antimicrobial activity against pathogenic bacteria.. Enzyme Microb Technol. 2017;97:114121. doi:10.1016/j.enzmictec.2016.10.018

Related Elements

Silver

See more Silver products. Silver (atomic symbol: Ag, atomic number: 47) is a Block D, Group 11, Period 5 element with an atomic weight of 107.8682. Silver Bohr ModelThe number of electrons in each of Silver's shells is 2, 8, 18, 18, 1 and its electron configuration is [Kr]4d10 5s1. The silver atom has a radius of 144 pm and a Van der Waals radius of 203 pm. Silver was first discovered by Early Man prior to 5000 BC. In its elemental form, silver has a brilliant white metallic luster. Elemental SilverIt is a little harder than gold and is very ductile and malleable, being exceeded only by gold and perhaps palladium. Pure silver has the highest electrical and thermal conductivity of all metals and possesses the lowest contact resistance. It is stable in pure air and water, but tarnishes when exposed to ozone, hydrogen sulfide, or air containing sulfur. It is found in copper, copper-nickel, lead, and lead-zinc ores, among others. Silver was named after the Anglo-Saxon word "seolfor" or "siolfur," meaning 'silver'.

Chlorine

Chlorine is a Block P, Group 17, Period 3 element. Its electron configuration is [Ne]3s23p5. The chlorine atom has a covalent radius of 102±4 pm and its Van der Waals radius is 175 pm. Chlorine ModelIn its elemental form, chlorine is a yellow-green gas. Chlorine is the second lightest halogen after fluorine. It has the third highest electronegativity and the highest electron affinity of all elements, making it a strong oxidizing agent. It is rarely found by itself in nature. Chlorine was discovered and first isolated by Carl Wilhelm Scheele in 1774. It was first recognized as an element by Humphry Davy in 1808.

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