Increase in polyunsaturated fatty acids and carotenoid accumulation in the microalga Golenkinia brevispicula (Chlorophyceae) by manipulating spectral irradiance and salinity

Abstract

Microalgal biotechnology offers a promising platform for the sustainable production ofdiverse renewable bioactive compounds. The key distinction from other microbialbioprocesses lies in the critical role that light plays in cultures, as it serves as a sourceof environmental information to control metabolic processes. Therefore, we can usethese criteria to design a bioprocess that aims to stimulate the accumulation of targetmolecules by controlling light exposure. We study the effect on biochemical andphotobiological responses of Golenkinia brevispicula FAUBA‐3 to the exposition ofdifferent spectral irradiances (specifically, high‐fluence PAR of narrow yellow spectrum complemented with low intensity of monochromatic radiations of red, blue, andUV‐A) under prestress and salinity stress conditions. High light (HL) intensity coupledto salinity stress affected the photosynthetic activity and photoprotection mechanisms as shown by maximal quantum yield (Fv/Fm) and non‐photochemical quenching(NPQmax) reduction, respectively. HL treatments combined with the proper dose ofUV‐A radiation under salinity stress induced the highest carotenoid content (2.75 mg gdry weight [DW]−1) composed mainly of lutein and β‐carotene, and the highest lipidaccumulation (35.3% DW) with the highest polyunsaturated fatty acid content (alpha‐linolenic acid (C18:3) and linoleic acid (C18:2)). Our study can guide the strategies forcommercial indoor production of G. brevispicula for high‐value metabolites.