Increase in polyunsaturated fatty acids and carotenoid accumulation in
the microalga Golenkinia brevispicula (Chlorophyceae) by manipulating
spectral irradiance
Abstract
Microalgal biotechnology offers a promising platform for the sustainable
production of diverse renewable bioactive compounds. The main difference
from other microbial bioprocesses is the crucial role that light plays
for cultures since it can be used as a source of environmental
information to control metabolic processes. Therefore, we can use these
criteria to design a bioprocess that aims to stimulate the accumulation
of target molecules by controlling light exposure. We study the effect
on biochemical and photobiological responses of Golenkinia
brevispicula FAUBA-3 to the exposition of different spectral
irradiances (high-fluence PAR of narrow yellow spectrum complemented
with low intensity of monochromatic radiations of red, blue, and UV-A)
under pre-stress and salinity stress conditions. High light coupled to
salinity stress affected the photosynthetic activity and photoprotection
mechanisms as shown by maximal quantum yield (
Fv/Fm) and non-photochemical
quenching (NPQ max) reduction, respectively. High light
treatments combined with the proper dose of UV-A radiation under
salinity stress induced the highest carotenoid content (2.75 mg g DW
-1) composed mainly of lutein and β-carotene, and the
highest lipid accumulation (35.3 % DW) with the highest PUFA content
(ALA (C18:3) and LA (C18:2)). Our study can guide the strategies for
commercial indoor production of G. brevispicula for high-value
metabolites.