Microalgas do semiárido: florações nocivas, variabilidade sazonal e suas possíveis aplicações biotecnológicas

Abstract

Microalgae and cyanobacteria are eukaryotes and prokaryotes, respectively, photosynthetic and use atmospheric CO2, light and inorganic compounds for their growth. In addition, they produce nutritional, bioactive compounds and some species may produce toxins (like some species of cyanobacteria and dinoflagellates). The present study aimed to identify and isolate species from the phytoplankton community of reservoirs located in the semiarid Pernambucano and later to evaluate the biotechnological potential of microorganisms previously isolated from the center of culture of the Laboratório de Produção de Alimento Vivo (LAPVI-UFRPE/Sede). For the collection of these organisms a network with a mesh of 20μm was used, being part of the collected material fixed in formaldehyde to 4% and the rest submitted to the culture. After the sorting of all collected material, the canonical correspondence analysis was performed to evaluate possible interactions between the abiotic parameters and the species found. The evaluation of biotechnological potential occurred by the bioremediation capacity test of Chlorella vulgaris in effluent from a biofloc system (BFT). Twenty-one taxa were recorded, most of them of the class Chlorophyceae. Among the species found, we highlight the presence of Ceratium furcoides, an exotic dinoflagellate that is found in a growing geographic expansion in Brazil. In the evaluation of bioremediation potential, the presence of Chlorella vulgaris promoted a reduction in the levels of nitrogenous and phosphate compounds of the BFT effluent of approximately, 79.2% and 48%, respectively. In addition to the removal capacity of these compounds, BFT effluent presented as potential medium for the cultivation of this microalgae.