Cultivo de microalgas en una zona de alta irradancia

Abstract

Microalgae are considered a promising source of high-value products (carotenoids, omega-3, DHA) as well as feedstocks for feed/food, bulk chemicals, cosmetics/pharmaceutics and biofuels. Moreover, they can be used in bioremediation tasks of polluted environments, as part of the CO2 gas mitigation process or in wastewater treatment. Light is the main substrate for the production of microalgae. Therefore, areas with high irradiances and moderated temperatures along the year are considered to be optimal for the production of microalgal biomass. However, the photosynthetic process is not a perfect process and the low efficiencies obtained in outdoor cultivation processes, especially when cultures are exposed to high irradiance conditions, are limiting the development of feasible production systems at industrial scale. Considering the excess of light hinders the photosynthetic efficiency outdoors, more knowledge on the effect of photo-saturation over the complete photosynthetic process is needed with the aim of enhancing the microalgal productivities. In this sense, simulation experiments at laboratory scale where real outdoor irradiance conditions can be simulated while keeping the rest of operational parameters optimal might result in a better understanding of the microalgal cultivation process. In this Thesis Dissertation, irradiance conditions typical from the Summer and Winter period in Huelva (south-west of Spain), geographical area with a high annual irradiance, were simulated. Different cultivation strategies leading to avoid/reduce the effects of photo-saturation and/or photo-inhibition over the microalgal cultures were evaluated and their effect over the final production of the microalgae Chlorella sorokiniana was discussed. Obtained results show the potential of such microalgae to be cultivated in a high irradiance area as Huelva, the study site, for the obtainment of biomass and high-value molecules as lutein. Moreover, the positive effect of light dilution over the photosynthetic efficiency was confirmed.