Antimicrobial Activity on Silver Nanoparticles from Spirulina Platensis Microalgae by Green Synthesis
Dr. Myat Myat Thaw, Professor, Department of Chemistry, University of Yangon, Yangon, Myanmar Email: dr.myat.myat.thaw@gmail.com Department of Chemistry
7th Virtual Nanotechnology Poster Conference, 2017 Abstract In Myanmar, the natural Spirulina is produced from the natural lake of Ye Kharr Lake. The aim of this research was to investigate the antimicrobial activity of silver nanoparticles from Spirulina. Microalgae are microscopic photosynthesis organisms that are found in both marine and fresh environments. Spirulina platenis ( blue green algae) is very important role for health food. Silver nanoparticles from spirulina was synthesized by green synthesis. This green synthesis gives the greater potential biomedical applications of silver nanoparticles. Silver nanoparticles from spirulina was obtained by calcinations at 500 0 C for 3 h and characterized by XRD , SEM and FT IR techniques. Average crystallite size of silver nanoparticles from spirulina was found to be 25.30 nm by using Debye Scherer equation. Antimicrobial activity of silver nanoparticles from spirulina platensis was carried by using gram positive bacteria (Bacillus subtilis, Bacillus pulamis and staphyloccus aureus), gram negative bacteria (Escherichia coli and Pseudomonas flurescencens) and Candida albicans fungus strain. Among these strains, candida albicans indicated the highest antimicrobial activity of spirulina platensis. Keywords: Microalgae, spirulina platensis, antimicrobial activity, XRD, SEM Spirulina
Introduction What is Spirulina? Spirulina is a blue-green microalgae which grows in alkaline water. It is highly nutritious and actually a total food for human nutrition. Human can survive with spirulina and water without taking any other food. The spirulina can be found in the volcanic crater lakes and the natural lakes, having high pH level. Spirulina makes you healthy, long life and free from diseases because nearly all vitamins are proportionately in it.
Phylum Class Order Family Genus Species
Cyanophyta Cyanophyceae Oscillatorcales Oscillatoriaceae Spirulina S . plantensis 5
Figure 1. Spirulina Platensis
Aim of this work: Objectives:
To apply silver nanoparticles by green synthesis for biomedical and food applications
To synthesize the silver nanoparticles by green synthesis To characterize the silver nanoparticles by using by modern instruments To apply the silver nanoparticles from spirulina platensis for biomedical and food applications
Materials and Methods Figure 2. Ye Kharr Lake
Sample collection of Spirulina platensis The samples were collected from Sagaing June Pharmaceutical and Foodstuff Industry Ltd, Ye Kharr Lake, Sagaing Region located at North Latitude 22˚ 02' 57.4" and East Longitude 95˚ 53'17.4". Ye kharr Lake produces Spirulina platesis naturally.
Synthesis and characterization of silver nanoparticles Dried Spirulina platensis (10g) was suspended in 500 mL conical flask and mixed with 100mL of 1mM silver nitrate by using deionized water (pH7) at room temperature for 2 hours. This solution was shaken in a shaker at 1000 rpm for one hour. It was concentrated and heated in Electric muffle furnace (Tactical 308, Gallenkamp, England) for 3 hours. The synthesized silver nanoparticles were characterized by XRD analysis for detecting of size and structure. Scanning electron microscope was carried out to determine the shape and morphology.
Results and Discussion X ray diffraction analysis It was observed that the sharp peaks of the silver nanoparticles indicated well-defined Miller indices of (111), (200), and (220). These peaks are well matched with standard library data of (PDS 04-0783) and is shown in figure 3. Scanning electron Microscopy Analysis The scanning electron microscopy results clearly indicate the formation of spherical silver nanoparticles with its size ranging between 50 nm and 100 nm is shown in figure 4. Antimicrobial Activity The antimicrobial activity of spirulina and silver nanoparticles were tested and compared by using six microorganisms. Silver nanoparticles showed a characteristic inhibition zone of 23.06 mm and 28.19 mm diameter against Bacillus subtilis, 18.50 mm and 23.29 mm against staphylococcus aureus, 20.87 mm and 28.05 mm against Pseudomonas aeruginosa, 15.90 mm and 21.43 mm against Bacillus pumilus, 35.06 mm and 49.49 mm against Candida albicans and 31.70 mm and 38.98 mm against E coli respectively. Among these strains, it was observed that E coli and Candida albicans are found the higher inhibition zone with silver nanoparticles.
Conclusion
Figure3. XRD diffractogram of Figure 4. SEM image of Silver nanoparticles Silver nanoparticles from Spirulina platensis from spirulina platensis by green synthesis 1
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(a) Bacillus subtilis
Silver nanoparticles are obtained by green synthesis. Determination of antimicrobial activity of silver nanoparticles was done by using six microorganisms. It was observed that the highest antimicrobial activity of silver nanoparticles on Candida albicans and E coli strains. 1. Based on these results obtained, metals nanoparticles are not showing the same sensitivity of all the microbial species and strains. 2. The toxicity of silver nanoparticles plays another significant role in the determination of antimicrobial activity. References Ru W..,Xie.X.B et al.,(2010), " Antibacterial Activity and Mechanism of Silver Nanoparticles on Escherichia coli, Appl Microbiol Biotechnol 85. 1115-1122. Geoprincy G. et al.,(2012), Novel Antibacterial Effects of Alumina Nanoparticles on Bacillus Cereus and Bacillus Subtilis in Comparison with Antibiotics, International Journal of Pharmacy and Pharmaceutical Science,4.544-548
Figure 7. Location of spirulina platensis in Sagaing Region, Myanmar
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(d) Bacillus pumilus
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(b)Staphylococcus aureus (c)Pseudomonas aeruginosa
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(e) Candida albicans
(f) Escherichia coli Figure 5. Antimicrobial Activity of Silver Nanoparticles from spirulina platensis
Figure 6. Antimicrobial Activity of Silver Nanoparticles from spirulina platensis