Microalgae mediated photoproduction of β-carotene in aqueous–organic two phase systems

Abstract

Improving productivity is a usual requirement for most biotechnological processes, and the utilisation of two-phase aqueous organic systems has proved to be an effective way to improve the productivity of poorly water-soluble or toxic compounds. The high hydrophobicity of β-carotene, which is highly demanded by the pharma and agrofood industry, makes it a good candidate for aqueous/organic biphasic photoproduction. In the present work we have investigated the viability of a two-phase system for the production of β-carotene by the marine microalgae Dunaliella salina using decane as organic phase. Decane, with a log P octanol value of 5.6, showed no toxicity to Dunaliella cells for more than 72 h, and its ability for β-carotene extraction is acceptable. Transferring Dunaliella cells from standard to carotenogenic conditions caused inhibition of chlorophyll production and induced a strong synthesis of β-carotene. The two-phase aqueous/decane system was stable and β-carotene content of the cells was increasing during 4-days. About 8% of the total carotenoids produced were excreted and extracted into the decane phase.