Antibacterial activities of C-phycocyanin from Spirulina laxa

Abstract

 Spirulina is a phylum of cyanobacteria, which are known for their distinctive photosynthetic capacity. These filamentous, gram-negative cyanobacteria or blue-green algae are one of the sources of natural bioactive compounds with therapeutic qualities like C-phycocyanin (C-PC). In this study, the C-phycocyanin (CPC/β) gene was amplified from local isolate of Spirulina laxa. The CPC/β gene (1119bp) was digested by EcoRI and BamHI, then ligated with the expression vector pGEM®-3Zf (+) to form recombinant DNA, and then was transformed to an expression host E. coli BL21(DE3). For the production of the CPC protein, we induced by 1mM IPTG. The expressed protein was analyzed by 12% SDS-PAGE. The molecular weight around 37 kDa. The antibacterial assay revealed that spirulina phycocyanin produced inhibition zones against four pathogenic bacteria, both Streptococcus agalactiae and Staphylococcus aureus, as well as Escherichia coli and Klebsiella pneumonia.