Chlorella vulgaris as a producer of lipids for antibacterial, antibiofilm and antifungal properties

The aim of this study was to investigate the antibacterial, antifungal, and anti-biofilm activities of the methanolic extract of marine Chlorella vulgaris along with its lipid composition, including carotenoids. The C. vulgaris strain, isolated from the Mediterranean coast of northern Morocco, was identified morphologically and molecularly by partial sequencing of the 18S rRNA gene. The methanolic extract of C. vulgaris demonstrated significant antibacterial activity against both Gram-positive and Gram-negative pathogenic bacteria, with MIC values ranging from 3.12 to 12.5 mg mL−1. The antibiofilm activity of the extract was dose-dependent against Staphylococcus epidermidis and Pseudomonas aeruginosa. The extract demonstrated antifungal activity against four fungal strains. A. brasiliensis was shown to be the most sensitive species, whereas M. hiemalis was the least sensitive one. The identified lipid compounds mainly consisted of polar species e.g. phospholipids and carotenoids including lutein and neoxanthin, whose antimicrobial activity is generally recognised.