Comparative analysis of carotenoid synthesis and transcriptome of a microalga Chlorophyta MCH-35, potential lutein producer, in response to different quality light

Light plays an important role in the regulation of metabolic pathways related to photoprotection of the photosynthetic apparatus. The objective of our work was to evaluate in the microalga Chlorophyta MCH-35, isolated in the coastal desert of Antofagasta and potential producer of lutein, the influence of white, blue and red light, through LED technology, on the accumulation of carotenoids analyzed by HPLC and the associated molecular regulation mechanisms, through RNA-seq. The results showed that blue and white light stimulate carotenoid productivity with values close to 1.3 mg L-1 day- 1, in contrast to red light (& AP;0.5 mg L-1 day- 1), being lutein the main representative with values close to 0.3 % dry.wt. On the other hand, it was observed that blue light also induces the accumulation of other carotenoids such as astaxanthin, violaxanthin, 8-carotene and zeaxanthin, relating this result to the up-regulation of 11 of the 12 detected transcripts related to key enzymes present in the pathway of biosynthesis of these pigments. Finally, it has been observed that light under wavelength stress treatments induce the regulation of transcripts involved in metabolic pathways related to photoprotection mechanisms in general. This study provided the bases for future research on metabolic regulation in microalgae cultures based on the implementation of light induction systems.