Production of phycocyanin by Leptolyngbya sp. in desert environments

Abstract

Leptolyngbya sp. QUCCCM 56 was investigated as a possible alternative to A. platensis, for the production of phycocyanin-rich biomass under desert conditions. Under elevated temperatures and light intensities, of up to 40 °C and 1800 μmol·m−2·s−1, the strain's biomass productivity was up to 45% higher as compared to reported productivities for A. platensis, with comparable phycocyanin content. Increasing temperatures were found to improve the biomass productivity and phycocyanin content, which, at 40 °C, were 1.09 ± 0.03 gX·L−1·d−1 and 72.12 ± 3.52 mgPC·gX−1, respectively. The optimum biomass productivity was found at a light intensity of 300 μmol·m−2·s−1, with higher light intensities causing a decrease of 15%. Furthermore, of the various phycocyanin extraction methods tested, bead-beating in phosphate buffer had the highest combined phycocyanin yield (169.9 ± 3.6 mgPC·gX) and purity (7.37 ± 0.16) for Leptolyngbya sp. For A. platensis, this extraction method also resulted in the highest extract purities (3.78 ± 0.04). The extract purities obtained for Leptolyngbya sp. are considerably higher than other reported phycocyanin purities, and further investigation is recommended to study the scale-up of both Leptolyngbya sp. and bead-beating for commercial scale high-grade phycocyanin production under desert conditions.