Evaluation of the Sporicidal Activity of Ethanol Extract of Arctium lappa Root against Bacillus cereus

Background: Bacillus cereus is one of the most common causes of food spoilage, keratitis, endophthalmitis, and panophthalmitis. These bacteria produce spores which are resistant to chemical and physical agents. Nowadays, the sporicidal properties of plants have been considered as alternatives to chemical sporicidal agents. Materials and Methods: In this empirical-experimental study the effect of ethanol extract of edible burdock (Arctium lappa) root has been studied on Bacillus cereus spores. In this investigation, the suspensions of tested microorganisms were cultured in sporulating agar. Sporulation process was assessed by optical microscopy following the staining of spores. Then the produced spores were exposed to various concentrations (100, 150, 200, 250, 300 mg/mL) of ethanol extract of edible burdock (Arctium lappa) root and finally the remaining spores were counted. With increasing concentrations of ethanol extract, the number of spores declined. Results: Pearson correlation showed inverse relation between the spores count and concentration of ethanol extract of edible burdock (Arctium lappa) root (r=-0.765, p < 0.001). The most effective extract concentration was 300 mg /mL. Conclusion: Ethanol extract of edible burdock (Arctium lappa) root, has sporicidal activity. Only, the sporicidal nature of ethanol extract has been evaluated by this study; therefore, the assessment of other extracts and essences is necessary.