Antimicrobial effect of extract of Spirulina platiensis on pathogenic bacteria and fungi

With the increase of antibiotic resistance, the effort to reduce the consumption of antibiotics by replacing natural active compounds has received much attention in recent years. Cyanobacteria are highly diverse and contain metabolites with medicinal, nutritional and antimicrobial properties.

I In this study, the effect of Spirulina platensis extract on two Gram-positive bacteria Staphylococcus aureus subsp.marcescens and Bacillus subtilis subsp.subtilis (bscillus natto), two Gram-negative bacteria Escherichia coli and Klebsiella pneumoniae and two fungi Penicillium and Aspergillus niger. was investigated. Spirulina platensis hydroalcoholic extract was prepared by maceration method and its antimicrobial activity was evaluated by disk and agar well diffusion methods.

The results showed that the growth of Gram-positive Bacillus was inhibited by Spirulina extract and Staphylococcus aureus showed no sensitivity to the existing Spirulina. Generally, gram positive bacteria were more sensitive than gram negative bacteria. Also, Aspergillus niger showed more antifungal activity than Penicillium. The supernatant showed better results than the hydroalcoholic extract, and diameter the inhibition zone was from 1 to 15 mm.

In general, due to the increasing resistance of pathogenic fungi to common antifungals, it is recommended that with more research on Spirulina microalgae, the antimicrobial compounds of this algae can be used in the treatment of infectious and fungal diseases.