Antioxidant and antibacterial activities of C-phycocyanin from common name Spirulina platensis

In this study, the antibacterial and antioxidant properties of Cphycocyanin (CPC) from Spirulina platensis were evaluated. The extraction and purification of CPC were carried out using lyzosyme and ammonium sulphate precipitation, respectively. DPPH radicalscavenging activity, ferric reducing antioxidant power (FRAP) and Fe2+chelating activity were used for evaluation of antioxidant properties of CPC. Antibacterial activity was also performed using agar well diffusion and microdilution [minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC)]. The selected bacteria were Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Streptococcus iniae and Yersinia ruckeri. The results showed that the biomass production was 1120 mg L1 and CPC concentration in crude extracts and purified by (NH4)2SO4 were also 1.815 and 3.75 mg ml1, respectively. The results of DPPH, FRAP and Fe2+chelating activities of CPC was 45.75%, 0.051 mg TAE g1 and 40.23% at zero time and 41.56%, 0.046 mg TAE g1 and 36.56% after 60 days at 18 °C, respectively. The results of agar well diffusion indicated that L. monocytogenes and S. iniae were the most sensitive and resistant, respectively among examined bacteria in different concentrations of CPC (0 25 micro;g ml1) and the mean of inhibition zones were also 7.5022.11mm. The results of MIC and MBC of CPC (as micro;g ml1) were 50500 and 100500, respectively. As a conclusion, CPC from S. platensis had high potential of antioxidant activity in vitro and it can be used as natural antioxidants in variety of foods. Antibacterial activity of CPC was lower than other algal pigments (such as astaxanthin and CPC in other cyanobacteria).