Evaluating Antibacterial Effect of Green Synthesis Oxide Iron Nanoparticles Using Cytoplasmic Extract of Lactobacillus casei

With regard to the drug resistance, special attention has been placed on researches for discovering new antimicrobial substances such as nanoparticles. In green synthesis biological resources such as bacteria and yeast are used for producing metal nanoparticles.  In this research, we used the Lactobacillus casei extract as a biological source for producing iron oxide nanoparticles and antibacterial effects of these nanoparticles against the standard strains of Escherichia coli and Staphylococcus aureus were investigated.

for synthesis of green iron oxide nanoparticles, cytoplasmic extract of Lactobacillus casei and iron sulfate solution 10-3M were mixed and incubated for 3 weeks at 37 ° C in the presence of 5% carbon dioxide. Synthesis of iron oxide nanoparticles were evaluated using X-ray diffraction pattern and Transmission electron microscopy. Antibacterial effects of nanoparticles with dilution of 10, 100 and 1000 micro-grams per milliliter on two standard strains of Escherichia coli and Staphylococcus aureus were evaluated.

Synthesis of iron oxide crystals was confirmed by XRD analysis. Based on transmission electron microscopy the average of nanoparticles was about 15 nm with a spherical shape. Antimicrobial effect of nanoparticles showed that at concentration of 100 and 1000 µg/ml has an inhibitory effect on the growth on Staphylococcus aureus equal to 12.03±0.32 and 16±0.5, respectively. The only concentration that showed significant effect was 1000µg/ml (p≤0.001). While are ineffective against Escherichia coli.

The results of this study indicated that producing iron oxide nanoparticles using cytoplasmic extract of Lactobacillus casei is a biologically safe method and very noteworthy in medicine and pharmacology and may be considered as a good candidate for the treatment of bacterial infections.