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Biosynthesis of selenium nanoparticles using lactic acid bacteria
- 1. BIOSYNTHESIS, CHARACTERISATION, AND BIOLOGICALACTIVITYOF SELENIUM NANOPARTICLES SYNTHESISED USING Lactobacillus sp. NAME – Sanjana Yadav GUIDE NAME – Dr. Snehal Gagre CLASS – TY Bsc Biotechnology ROLL.NO – 243231040 SEAT No. - 10101
- 2. ABSTRACT Selenium nanoparticles (SeNPs)are gaining attention for their potential in medicine, agriculture, and environmental science. In this study, we used Lactobacillus sp. to biosynthesize SeNPs, exploring how different sodium selenite concentrations (2 mM, 4 mM, and 6 mM) affect their formation. A striking color change from pale yellow to orange red signaled successful synthesis, which was confirmed by UV-Vis spectroscopy. FTIR analysis showed that biomolecules from the bacteria helped stabilize the nanoparticles. The main objectives of the study were as follows :- • To synthesize Selenium nanoparticles using Lactobacillus sp. • Characterization of synthesized Se-NPs using bioanalytical techniques. • To evaluate biological activity of biosynthesised selenium nanoparticles.
- 3. INTRODUCTION • Nanotechnology istransforming science by bringing together physics, chemistry, and biology to create tiny materials with powerful properties. Among these, metal nanomaterials like selenium have exciting applications in medicine, food safety, and biosensors. • However, traditional methods of making these nanoparticles often come with challenges like toxicity and difficulty in large-scale production. That’s where biological or "green" synthesis comes in—using natural processes to create safer, eco-friendly nanoparticles. • Selenium is an essential nutrient that supports immunity and overall health, but too much of it can be toxic. Interestingly, certain lactic acid bacteria (LAB), commonly found in foods like curd, can naturally convert selenium salts into selenium nanoparticles (SeNPs). • This study explores how Lactobacillus sp. from curd can be used to synthesize SeNPs from sodium selenite. While these nanoparticles show great potential in medicine, their safety and compatibility with the human body need further research to unlock their full potential.
- 4. MATERIALS AND METHODS •MATERIALS – 1. Curd 2. De Man, Rogosa and Sharpe (MRS) Broth 3. Antibiotic (100mg/ml) 4. Escherichia coli culture 5. Staphylococcus aureus culture 6. Agar Powder (Bacteriology grade-HiMedia) 7. Sodium selenite (SRL )
- 5. MATERIALS AND METHODS •METHODS – 1. Isolation and Characterization of Lactobacillus 2. Synthesis of Selenium nanoparticles 3. Isolation and purification of Selenium nanoparticles 4. Antimicrobial activity of synthesized SeNPs
- 6. RESULTS Lactobacillus incubated withsodium selenite solution Change in colour from pale yellow to orange – red displayed by the media after incubation of 2 days indicated reduction of sodium selenite into selenium nanoparticles
- 7. RESULTS Tubes with positiveand negative control for determining the MIC. All of the tubes were observed to be turbid.
- 8. RESULTS Graph depicts thepeaks for scanned range of 200-800nm on UV-Vis spectrophotometer of 4mM concentration of SeNPs. Graph depicts the peaks for scanned range of 200-800nm on UV-Vis spectrophotometer of 6mM concentration of SeNPs.
- 9. RESULTS Peaks of FTIRfor 4mM concentration of sodium selenite Peaks of FTIR for 6mM concentration of sodium selenite
- 10. DISCUSSIONS • Selenium nanoparticles(SeNPs) synthesized using Lactobacillus sp. provide a green alternative to chemical methods. • FTIR analysis indicated the presence of hydroxyl (-OH), amine (-NH), and carboxyl (-COOH) groups, suggesting biomolecule-mediated stabilization. These biomolecules prevent aggregation, ensuring SeNPs’ biocompatibility for applications in agriculture, medicine, and aquaculture.
- 11. DISCUSSIONS • The redcolor observed was due to surface plasmon resonance (SPR). UV-Vis spectrophotometer showed peaks around ~318nm, aligning with previous biosynthesis studies. • Unexpected turbidity in all test tubes prevented MIC determination. Possible reasons include insufficient SeNP concentration, aggregation reducing antimicrobial effectiveness, or bacterial resistance affecting nanoparticle uptake. Future studies should optimize dosage, reduce particle size, or increase incubation time to enhance antimicrobial efficiency.
- 12. CONCLUSION • Microbial synthesisof SeNPs, especially using Lactobacillus sp., is a key advancement in nanobiotechnology. • Higher sodium selenite concentrations led to longer reduction times as compared to lower concentrations. • Green synthesis is cost-effective, stable, and eco-friendly, supporting large-scale applications. • Biogenic SeNPs hold major potential for aquaculture, enhancing fish health and requiring further antimicrobial optimization.
- 13. REFRENCES • Murugesan etal. (2019): Murugesan, G., Nagaraj, K., Sunmathi, D., & Subramani, K. (2019). Methods involved in the synthesis of selenium nanoparticles and their different applications —a review. European Journal of Biomedical and Pharmaceutical Sciences, 6(4), 189–194. http://www.ejbps.com • Visha et al. (2015):Visha, P., Nanjappan, K., Selvaraj, P., Jayachandran, S., Elango, A., & Kumaresan, G. (2015). Biosynthesis and structural characteristics of selenium nanoparticles using Lactobacillus acidophilus bacteria by wet sterilization process. International Journal of Advanced Veterinary Science and Technology, 4(1), 178 183. http://scientific.cloud- journals.com/index.php/IJAVST/article/view/Sci-312. • Rao, V., & Poonia, A. (2024):Microbial biosynthesis of selenium nanoparticles using probiotic strain and its characterization. Journal of Food Measurement and Characterization. https://doi.org/10.1007/s11694-024-02581-z • Martínez, F. G., Moreno-Martin, G., Pescuma, M., Madrid-Albarrán, Y., & Mozzi, F. : Biotransformation of selenium by lactic acid bacteria: Formation of seleno-nanoparticles and seleno-amino acids. VI International Symposium on Lactic Acid Bacteria. Retrieved from https://bicyt.conicet.gov.ar/fichas/produccion/12227955 • Ingole, A. R., Thakare, S. R., Khati, N. T., Wankhade, A. V., & Burghate, D. K. (2010). Green synthesis of selenium nanoparticles under ambient condition. Journal Name, 7(7), 485–489.
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