Antimicrobial property of cell wall lysed Chlorella, an edible alga

Abstract

Chlorella vulgaris is a green microalga, extensively used as a food supplement. It is a rich source of carbohydrates, proteins, antioxidants, beta carotene, and minerals. Rigid cell wall hinders its wider acceptability as a food additive. In this report, we have used cell wall free Chlorella extract in controlling opportunistic human pathogens. Opportunistic microbes are commensals but become pathogenic due to several intrinsic and extrinsic cues. Several recent studies have shown the emergence of multi-drug resistant strains. So as an alternative strategy we used Chlorella extract to study its efficacy as an effective agent against these pathogens. Our result suggests the extract is effective against Pseudomonas, Klebsiella, Bacillus, Staphylococcus, and Enterococcus. The zone of inhibition for Bacillus subtilis, Staphylococcus aureus, and Enterococcus faecalis is equivalent to Ofloxacin a broad-spectrum antibiotic. It is also equally effective for opportunist fungal pathogens particularly towards Candida albicans and Candida tropicalis and to some extent Candida parapsilosis. However, it is indifferent to multi-drug resistant Candida auris. The zone of inhibition is 40-50% as compared to fluconazole a known antifungal drug. Combining both antifungal and antibacterial susceptibility assay, it was concluded that Chlorella vulgaris is having antimicrobial properties. So, we are suggesting apart from having a good source of food supplement, Chlorella powder can be used as a health booster and could be an effective therapy in controlling opportunistic infections.