Optimization of green derived silver nanoparticle and antimicrobial effect on escherichia coli and pseudomonas aeruginosa
Date
2021-05
Authors
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Journal ISSN
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Publisher
Federal University of Technology, Owerri
Abstract
Nanoparticles can be synthesized using various approaches including chemical, physical, and biological. Chemicals used for nanoparticles synthesis and stabilization are toxic and lead to generation of non-ecofriendly by-products. The need for environmental non-toxic synthetic protocols for nanoparticles synthesis leads to increasing demand for green nanotechnology. The major advantage of using plant extracts for silver nanoparticle synthesis is that they are available, safe, and non-toxic. The leaves of ten (10) selected plants were washed several times with distilled water to remove the dust particles and air-dried to remove the residual moisture. The dried leaves were crushed using mechanical method and 10 gram of dried powder boiled in 100 ml of deionized water for 20 minutes. The aqueous extracts were separated by filtration with Whatman No. 1 filter paper and centrifuged at 1200 rpm for 5 minutes to remove heavy biomaterials. The extract were stored at 4°C until further use. The biochemical screening and identification of the isolates in the stock culture from the extract were carried out according to microbiological guidelines and standards. The colour change of the solution from yellow to dark green was indicative of the reduction process silver ion to silver-nanoparticles. The Box-benken design was adopted for the optimization of the silver nanoparticle production in a 3 x 3 design. Also, extracellular synthesis of silver nanoparticles from green plant was carried out to determine nanoparticle production. Synthesized silver nanoparticles were scanned by Ultra violet visible ray is spectrophotometer at the wavelength of 340 – 820 nm. Antibacterial effect was determined invitro using Kirby-Bauer method. The optimal conditions for the production of goatweed nanoparticle (GwNP) were (pH 8.0, temperature 350C and Time of 24 hours) which was different from the optimum conditions for Independence leaf (XXYNP) production at pH 8.0, temperature of 35 degree celsius and a time of 72 hours. Similar effects were observed in the experiment with all the samples. The antimicrobial activities of these samples demonstrated that the nanoparticles had antimicrobial properties which vary depending on the isolate and condition (temperature, pH and time).
Description
This thesis is for the award of Master of Science (MSc.) in Medical Microbiology
Keywords
Antimicrobial, extracellular, nanoparticles, spectrophotometer, biomaterials, Department of Microbiology
Citation
Ekaji, F. A. (2021). Optimization of green derived silver nanoparticle and antimicrobial effect on escherichia coli and pseudomonas aeruginosa [Unpublished Master's Thesis]. Federal University of Technology, Owerri, Nigeria