Sacarose como plataforma para cultivos heterotróficos microalgais

Abstract

Microalgae present the capacity to obtain energy from consuming organic substrates in the absence of luminosity. The heterotrophic cultivation supported by an exogenous source of Carbon is an important form of metabolites production of commercial interest and the choice of low-cost inputs to the formulation of culture mediums is of great importance to the global economic of biotechnological processes since it represents a significant percentual on the final cost of the product. In this sense, the aims of this work were: (I) formulate a culture medium synthetic based on different concentrations of sucrose for the use in heterotrophic cultivation, (II) evaluate the kinetic of sucrose consume and the biomass production, (III) determine the qualitative profile of the lipid fraction, (IV) characterize the bioproducts of intracellular nature, (V) determine the analysis of the water cycle of the process (energy balance, CO2 emissions, and water balance). The results obtained demonstrated that the microalgae Phormidium autumnale had its best performance in the process in the relation C/N de 40, reaching an oil productivities of 18.9 mg/L/h. On the best condition, the results showed that the biodiesel production of microalgae has a positive energy production (50.59 MJ) associated with a low water consumption (28.38 m3/ kg) e low CO2 emissions (9.18 kg CO2-eq). The composition of this oil was predominately saturated (45.20%), monounsaturated (34.70%) and polyunsaturated (19.90%), resulting in quality characteristics of biodiesel adequate on the national (ANP 255) and international norms (ASTM 6751 e EN 14214).