ANALYSIS AND QUANTIFICATION OF COMPOUNDS FROM MICROALGAE USED IN THE FOOD INDUSTRY

VELAZQUEZ, MARIA B.; BARCHIESI, JULIETA; BUSI, MARÍA V.; GOMEZ-CASATI, DIEGO F.; ACIÉN-FERNANDEZ, GABRIEL

Mendoza

Congreso; LVIII Annual Meeting of the Argentine Society for Biochemistry and Molecular Biology Research; 2022

Microalgae are simple unicellular or multicellular microorganisms spread throughout the planet, in both aquatic and terrestrial ecosystems. In general, they are highly efficient in CO2 fixation and utilization of solar energy to produce biomass, with an efficiency four times higher than that of plants. The composition of microalgae (lipid, carbohydrate and protein content) depends on the species considered and, even among the same species, on the system and cultivation conditions. In addition to providing proteins and carbohydrates, microalgae are an important source of polyunsaturated fatty acids, which are essential for humans. Their consumption as food is restricted to a few species due to strict food regulations. The food market is dominated by Chlorella vulgaris, Dunaliella salina and Spirulina platensis in either tablet or powder form. This work presents the optimization of an economical culture media for the growth of Tetraselmis chuii (a strain recently approved for human consumption) considering a specific light intensity and CO2 injection. Besides, the measurements of photosynthetic efficiency, at fixed and variable irradiance, as well as the quantities of proteins, carbohydrates, lipids and chlorophylls at different days of culture at laboratory scale were studied for this alga, S. platensis and C. vulgaris. All strains showed a significant amount of proteins in their different growth phases (50 to 100 mg/mg dry biomass), with S.platensis standing out in exponential phase with an accumulation twice as high as the other two strains. C.vulgaris had a higher carbohydrate accumulation. S.platensis and C.vulgaris accumulated 50 % more lipids than T.chuii in their late growth phases. The analysis of the electron transport efficiency of the three strains allowed us to conclude that neither S.platensis nor T.chuii were inhibited at high radiation, whereas C.vulgaris was inhibited at 1200 PAR (Photosynthetically active radiation). S.platensis presented the highest photosynthetic capacity, followed by T.chuii and finally C.vulgaris.The results allow us to conclude that T.chuii is a good strain for mass production in photobioreactors because no photoinhibition was observed, and the quantum yields were similar to those of C.vulgaris, a strain currently used in current markets. In addition, the protein yield of this strain is expected to be similar to S.platensis, which could be of interest, both for human and aquaculture consumption or for obtaining amino acids to produce biofertilizers.