Avaliação da cinética de produção e caracterização da biomassa de Spirulina sp. (LEB18) cultivada em água residual da aquicultura
aquaculture, Spirulina, wastewater, agribusiness, bioremediation, biomolecules.
World aquaculture is growing, however, the use of large amounts of water coupled with the discharge of high nutrient concentrations in bodies of water, represent obstacles to the sustainable development of the sector. As a measure to mitigate the impacts caused, the use of microalgae such as Spirulina sp. (LEB18), is presented as an alternative to mitigate the adverse effects and reduce the costs of microalgal production through the use of aquaculture water as an alternative culture medium to Zarrouk. Given this, the present study aimed to evaluate the development of Spirulina sp. (LEB18) in aquaculture wastewater through growth parameters, biomass composition and nutrient removal. Cultures were performed in photobioreactors (1L) with aquaculture wastewater (100, 75, 50, 25, 0%) supplemented with different Zarrouk concentrations (0, 25, 50, 75 and 100%). The treatment with the highest yield was reproduced in raceway reactors with volumes of 5 and 210 L. The 25% treatment presented higher values of protein (65.73%) and phycocyanin (16.60 mg/mL). The highest content of polyunsaturated fatty acids (38.20%) and C18:3n6 (38.20%) was found in 25%, besides reaching removal rate of 94.01% (Sulfates), 93.84%. (Phosphate), 96.77% (Bromine) and 90.00% (COD). The treatment containing 25% (T25) was reproduced in the outdoor system in 5 L tanks, showed higher biomass production (3.33 gL-1) than the control (2.32 gL-1), as well as carbohydrates (69, 77%) and lipids (12.77%) were also higher. Spirulina sp. (LEB18) showed high phosphate removal (99.97%); COD (89.34%) and nitrogen nitrogen (81.10%). In addition, the presence of heavy metals was not found in biomass and concentration Al; Fe; Ca e Mg were superior to control. In the 210 L volume raceway reactors, the yield by T25 treatment (1.23 gL-1) was higher than the control (1.10 gL-1), as well as the carbohydrate content (47.37%), lipids (12.17%) and Phycocyanine (12.66%). The biomass presented Palmitic (C16:0) and Linolelaidic (18:2n6t) fatty acids and high removal of P (99.97%), Nitrate (81.10%), COD (89.34%) and Sulfates (54.06%). Given the results, it can be concluded that Spirulina sp. (LEB18) can be applied as a bioremediation agent of aquaculture wastewater, for high removal rates of organic and inorganic nutrients, producing biomass with different characteristics through the synthesis of certain biomolecules, which can be applied in various industrial and aquaculture sectors, including food and feed.