Biotechnological response curve of the cyanobacterium Spirulina subsalsa to light energy gradient

Abstract

Background Microalgae represent a suitable and eco-sustainable resource for human needs thanks to their fast growth ability, together with the great diversity in species and intracellular secondary bioactive metabolites. These high-added-value compounds are of great interest for human health or animal feed. The intracellular content of these valuable compound families is tightly associated with the microalgal biological state and responds to environmental cues, e.g., light. Our study develops a Biotechnological response curve strategy exploring the bioactive metabolites synthesis in the marine cyanobacterium Spirulina subsalsa over a light energy gradient. The Relative Light energy index generated in our study integrates the red, green and blue photon flux density with their relative photon energy. The Biotechnological response curve combined biochemical analysis of the macromolecular composition (total protein, lipid, and carbohydrate content), total sterols, polyphenols and flavonoids, carotenoids, phenolic compounds, vitamins (A, B1, B2, B6, B9, B12, C, D2, D3, E, H, and K1), phycobiliproteins, together with the antioxidant activity of the biomass as well as the growth ability and photosynthesis. Results Results demonstrated that light energy significantly modulate the biochemical status of the microalga Spirulina subsalsa revealing the relevance of the light energy index to explain the light-induced biological variability. The sharp decrease of the photosynthetic rate at high light energy was accompanied with an increase of the antioxidant network response, such as carotenoids, total polyphenols, and the antioxidant capacity. Conversely, low light energy favorized the intracellular content of lipids and vitamins (B2, B6, B9, D3, K1, A, C, H, and B12) compared to high light energy. Conclusions Results of the Biotechnological response curves were discussed in their functional and physiological relevance as well as for the essence of their potential biotechnological applications. This study emphasized the light energy as a relevant tool to explain the biological responses of microalgae towards light climate variability, and, therefore, to design metabolic manipulation of microalgae.

Changing of Chlorophyll Contents in Caulerpa lentillifera After Five-Day Harvest

“…The result showed that the decrease of the photosynthetic rate at high light energy was accompanied by increased antioxidant network response, such as carotenoids, total polyphenols, and antioxidant capacity. [16]. The chemical accumulation and function can cause environmental differences that influence seaweed growth [17].…”

Influence of Critical Parameters on the Extraction of Concentrated C-PE from Thermotolerant Cyanobacteria

“…Like green plants, they are known for their ability to carry out photosynthesis and produce oxygen. However, unlike plants, cyanobacteria do not have chloroplasts and lack a defined nucleus, distinguishing them as bacteria [ 1 , 2 , 3 ]. In scientific research and biotechnology, cyanobacteria have also proven helpful because of their ability to produce a variety of valuable compounds, such as biofuels, pharmaceuticals, industrial chemicals, and biofertilizers, through genetic engineering and metabolic modifications [ 4 , 5 , 6 , 7 , 8 , 9 ].…”