Acclimation and Characterization of Marine Cyanobacterial Strains Euryhalinema and Desertifilum for C-Phycocyanin Production

This study involves evaluation of two native cyanobacterial strains Euryhalinema and Desertifilum isolated from a mangrove pond in Haikou (China) for their possible phycocyanin (C-PC) production. Maximal growth rate with highest chlorophyll and C-PC accumulation were observed at 28 degrees C and 60 mu mol photons m(-2) s(-1) photon flux density for Euryhalinema sp., while for Desertifilum sp. at 32 degrees C and 80 mu mol photons m(-2) s(-1). Nitrogen and iron concentration trails revealed that double strength concentration of sodium nitrate and ferric ammonium citrate in original BG11 media increased growth rate and accumulation of C-PC for both strains. Three different C-PC extraction methods were tested. The combined extraction protocol of freeze-thaw and ultrasonication markedly increased the C-PC extraction efficiency and attained the food grade purity (A(620)/A(280) ratio >0.7), whereas a higher C-PC yield was found with Na-phosphate buffer. Furthermore, the clarified crude extract was used to purify C-PC by fractional ammonium sulfate [(NH)] precipitation, Sephadex G-25 gel filtration chromatography, and DEAE-sephadex ion exchange chromatography and attained analytical grade purity (A(620)/A(280) ratio >3.9). Taken together, both strains showed their potential to be domesticated for valuable phycocyanin production.

Automated summary

This study evaluated two native cyanobacterial strains for phycocyanin production and found that they showed potential for valuable production. Optimal growth rates and accumulation of phycocyanin were observed under specific conditions. Increasing the nitrogen and iron concentration in the media improved growth rate and C-PC accumulation. A combined extraction protocol of freeze-thaw and ultrasonication was effective in increasing C-PC extraction efficiency.