Evaluation of antimicrobial activities of blue-green algae-mediated silver and gold nanoparticles

Plant-based pathogenic microbes hinder the yield and quality of food production. Plant diseases have caused an increase in food costs due to crop destruction. There is a need to develop novel methods that can target and mitigate pathogenic microbes. This study focuses on investigating the effects of luteolin tetraphosphate derived silver nanoparticles (LTP-AgNPs) and gold nanoparticles (LTP-AuNPs) as a therapeutic agent on the growth and expression of plant-based bacteria and fungi. In this study, the silver and gold nanoparticles were synthesized at room temperature using luteolin tetraphosphate (LTP) as the reducing and capping agents. The synthesis of LTP-AgNPs and LTP-AuNP was characterized by Transmission Electron Microscopy (TEM) and size distribution. The TEM images of both LTP-AgNPs and LTP-AuNPs showed different sizes and shapes (spherical, quasi-spherical, and cuboidal). The antimicrobial test was conducted using fungi: Aspergillus nidulans, Trichaptum biforme, Penicillium italicum, Fusarium oxysporum, and Colletotrichum gloeosporioides, while the class of bacteria employed include Pseudomonas aeruginosa, Aeromonas hydrophila, Escherichia coli, and Citrobacter freundii as Gram (−) bacteria, and Listeria monocytogenes and Staphylococcus epidermidis as Gram (+) bacterium. The antifungal study demonstrated the selective size and shape-dependent capabilities in which smaller sized spherical (9 nm) and quasi-spherical (21 nm) AgNPs exhibited 100% inhibition of the tested fungi and bacteria. The LTP-AgNPs exhibited a higher antimicrobial activity than LTP-AuNPs. We have demonstrated that smaller sized AgNPs showed excellent inhibition of A. nidulans growth compared to the larger size nanoparticles. These results suggest that LTP-AuNP and LTP-AgNPs could be used to address the detection and remediation of pathogenic fungi, respectively.

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Recent progress of algae and blue–green algae-assisted synthesis of gold nanoparticles for various applications

Bioprocess and Biosystems Engineering ◽

10.1007/s00449-018-2012-2 ◽

2018 ◽

Vol 42 (1) ◽

pp. 1-15 ◽

Cited By ~ 16

Author(s):

Azhar U. Khan ◽

Masudulla Khan ◽

Nazia Malik ◽

Moo Hwan Cho ◽

Mohammad Mansoob Khan

Keyword(s):

Gold Nanoparticles ◽

Green Algae ◽

Recent Progress ◽

Blue Green Algae

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Multi-Faceted Role of Silver and Gold Nanoparticles Synthesized from Biowaste and its in vitroAntibacterial, Antifungal and Antidiabetic Activities

Letters in Applied NanoBioScience ◽

10.33263/lianbs111.30763092 ◽

2021 ◽

Vol 11 (1) ◽

pp. 3076-3092

Keyword(s):

Gold Nanoparticles ◽

Open Water ◽

Antimicrobial Activities ◽

Assay Method ◽

Innovative Strategy ◽

Silver And Gold Nanoparticles ◽

Resazurin Assay ◽

Ic50 Values ◽

Uv Visible

Increasing global fish production, increasing the amount of waste generated, unsafe disposal of waste tissues like head, bones, skin, scales, fins etc., into land and open water reservoirs leads to environmental pollution. The role of nanobiotechnology in biowaste management is an innovative strategy to handle environmental issues. This study synthesized silver and gold nanoparticles from prawn heads using one millimolar AgNO3 and HAuCl4. Biosynthesized nanoparticles were characterized by UV -Visible spectroscopy, XRD, FTIR, SEM and EDAX. The maximum absorption spectrum was monitored at 437 nm for silver and 552 for gold nanoparticles. Antimicrobial activity was assessed using the resazurin assay method. MIC values obtained for the tested organisms revealed antimicrobial activities. P aeruginosa, K. pneumoniae, showed MIC at 15.6 µg for silver nanoparticles, and A. niger, A.flavus and C.albicans showed MIC at 125 µg for gold nanoparticles synthesized from the prawn head extract. IC 50 values of α- amylase activity were found to be 296 and 356 µg/ml for the silver and gold nanoparticles, respectively. IC50 values are about 705 and 2475 µg/ml for the silver and gold nanoparticles, respectively, in α-glucosidase activity. Conclusively silver and gold nanoparticles synthesized from prawn head extract (PHE) showed antibacterial, antifungal, and antidiabetic activities.

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Plasmon-Modulated Excitation-Dependent Fluorescence and Antimicrobial Activities of Silver and Gold Nanoparticles Prepared with Eugenia unifloraL. extracts

10.21203/rs.3.rs-924921/v1 ◽

2021 ◽

Author(s):

Marcia Regina Franzolin ◽

Daniella dos Santos Courrol ◽

Karina de oliveira Gonçalves ◽

Lilia Coronato Courrol

Keyword(s):

Gold Nanoparticles ◽

Field Enhancement ◽

Ph Control ◽

Antimicrobial Activities ◽

Excitation Wavelength ◽

Xenon Lamp ◽

Local Field Enhancement ◽

Silver And Gold Nanoparticles ◽

Gram Positive Bacteria ◽

Nanoparticles Stability

Abstract Green synthesis using plant extract is a sustainable method to obtain silver and gold nanoparticles (Ag and AuNPs) and was employed in this work. The Eugenia uniflora L. fruits and leaves extracts were used in nanoparticles synthesis. The photoreduction process with a xenon lamp and pH control improved optical properties and nanoparticles stability. The UV-vis, TEM, FTIR, and Zeta potential of the prepared solutions were obtained. The fluorescence spectra of Ag and AuNPs were investigated at different excitation wavelengths, which showed two kinds of fluorescence peaks. The shorter wavelength peaks red-shift with the increasing excitation wavelength, which results from the electron interband transitions, and the longer fixed wavelength peaks due to the local field enhancement. Finally, the antimicrobial tests were performed with Gram-negative and Gram-positive bacteria and Candida albicans. The best results were obtained with EuAgNPs prepared with fruits extract, photoreduction, and pH 7.0 (with a mean of 95.12% ± 10.29% of inhibition).

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Freeze-Fracture Replication in the Ultrastructure of Blue-Green Algae

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100060386 ◽

1967 ◽

Vol 25 ◽

pp. 74-75

Author(s):

L. V. Leak

Keyword(s):

Cell Wall ◽

Electron Microscope ◽

Green Algae ◽

Three Dimensional ◽

Freeze Fracture ◽

Electron Microscopic ◽

Photosynthetic Membranes ◽

Blue Green Algae ◽

Cell Biol ◽

Cellular Components

Electron microscopic observations of freeze-fracture replicas of Anabaena cells obtained by the procedures described by Bullivant and Ames (J. Cell Biol., 1966) indicate that the frozen cells are fractured in many different planes. This fracturing or cleaving along various planes allows one to gain a three dimensional relation of the cellular components as a result of such a manipulation. When replicas that are obtained by the freeze-fracture method are observed in the electron microscope, cross fractures of the cell wall and membranes that comprise the photosynthetic lamellae are apparent as demonstrated in Figures 1 & 2.A large portion of the Anabaena cell is composed of undulating layers of cytoplasm that are bounded by unit membranes that comprise the photosynthetic membranes. The adjoining layers of cytoplasm are closely apposed to each other to form the photosynthetic lamellae. Occassionally the adjacent layers of cytoplasm are separated by an interspace that may vary in widths of up to several 100 mu to form intralamellar vesicles.

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