Antibacterial Activity of Spirulina Pigment Fraction Spirulina platensis

Spirulina platensis is a microalgae that is rich in nutrients. These organisms have a high protein content, in addition to being rich in secondary metabolites. Pigment is the secondary metabolite that is most abundant in Spirulina platensis. The pigment of Spirulina platensis consists of chlorophyll, carotenoids, and phycocyanin. These three pigments have been proven to have bioactivity as antibacterials. The aim of this study was to test the antibacterial activity of the pigment fraction in Spirulina platensis. Spirulina platensis extraction using methanol, fractionation was carried out using diethyl ether solvent. Pigment identification is carried out using thin layer chromatography (TLC). Antibacterial activity was carried out using the well method using S. aureus and MDR E.coli bacteria. Pigment in Spirulina platensis can be extracted using methanol solvent with a yield of 13.25% and fractionated using diethyl ether solvent with a yield of 8.67%. The results of identification using TLC showed that the pigments interested in the fraction were chlorophyll and carotenoid. The antibacterial activity test showed that the pigment fraction could inhibit S. aureus and E. coli bacteria at concentrations of 0.2, 0.3, and 0.4%. The antibacterial activity against S. aureus bacteria for a concentration of 0.2, 0.3, and 0.4% has a clear zone of 1.008 ± 0.011 cm, 1.044 ± 0.013 cm, and 1.156 ± 0.013 cm. Meanwhile, the antibacterial activity against E. coli at a concentration of 0.2, 0.3, and 0.4% had 0.754 ± 0.014 cm, 0.821 ± 0.017 cm, and 0.899 ± 0.013 cm.