Surfactant-assisted disruption and extraction for carotenoid production from a novel Dunaliella strain

Abstract

The screening for carotenoids-producing microalgal strains in Ilha do Sal (Cape Verde) has led to the isolation of 14 Dunaliella strains. Two of them, tentatively identified as Dunaliella salina SM1A and Dunaliella salina PL2A, display high values of biomass and β-carotene productivity. Therefore, their cultivation was scaled-up from flask to pilot-scale bioreactors. β-carotene production was implemented following a combined cell disruption-extraction process. To do that, the non-ionic surfactant Tergitol NP10 was proposed as lytic agent and antioxidant extractant, collaboratively with potassium-based inorganic and organic salts. The immiscibility regions were experimentally characterized, and the suitability of potassium phosphate and potassium citrate as effective segregation agents was confirmed by analyzing the size of the biphasic region and the tie-lines. Additionally, β-carotene extraction capacity was firstly demonstrated with model aqueous solutions, and corroborated with real microalgal biomass.