Optimization of the production of lipids and carotenoids in the microalga Golenkinia aff. brevispicula

AGUSTIN REARTE; FIGUEROA F. L.; GÓMEZ-SERRANO C.; MARSILI SANTIAGO NICOLÁS; FABRIZIO DE IORIO A. R.,; GÓNZALEZ-LOPEZ C.V.; CERÓN GARCÍA M. C.; ABDALA-DÍAZ R.T.; ACIÉN-FERNÁNDEZ F.G.

Algal Research

Algal Research

Año: 2020

2211-9264

Microalgae are a promising platform to produce natural pigments and lipids when compared to traditionalsources, since they present faster growth and biomass productivity and there is a wide diversity that has not beenstudied yet. The green microalgae belonging to the genus Golenkinia presents few reports of its biomass production and applications. In this work, the productivity of lipids and carotenoids was studied in the strainGolenkinia aff. brevispicula FAUBA-3 using a two-stage cultivation system: a frst step for biomass productionunder semicontinuous cultures, and a second step for the accumulation of lipids and carotenoids under batchsalinity stress (35 g L−1). The highest biomass productivity (0.92 g L−1 day−1) was obtained under a dilutionrate of 0.4 day−1. The growth rate (μ) was a hyperbolic function of average irradiance inside the culture (Eav).The optimum Eav was 88.4 μmol photons m−2 s−1 and the maximum specifc growth rate (μmax) was 0.85 day−1.Photoinhibition was observed above 570 μmol photons m−2 s−1 of Eav. The best photosynthetic performancewas obtained at 0.2 day−1 dilution rate but with lower biomass productivity due to nutrients and light limitation. High content of protein (30% DW) and polyunsaturated fatty acids (50% of total PUFAs) and low contentof carbohydrates (19% DW) were observed at high dilution rate, and the opposite response at low dilution rate.In the second culture stage, an increase of salinity induced lipid and carotenoid accumulation which improvedthe productivity to 89 mg L−1 day−1 and 1.3 mg L−1 day−1 of total lipids and carotenoids respectively compared to one-stage culture. Lutein, β-carotene and astaxanthin were the main carotenoid identifed in a decreasing order. Those results confrm that two-stage culture is an adequate strategy to optimize the carotenoidand lipid productivity in the promising strain Golenkinia FAUBA-3.