ABSTRACT Biorefineries based on microalgae produce biofuels and co-products with added value. Microalgae mainly require water, carbon dioxide and sunlight for growth. The bioproducts of the cultivation of these microorganisms can be fully used in a microalgae photobiorefinery. The objective of this work was to study the behavior of physico-chemical variables and kinetic and biological responses in industrial cultivation of Spirulina sp. LEB 18, aiming at the operation of a microalgal photobiorefinery. The maximum specific growth rate (0.133 1/d), the minimum generation time (5.2 d) and maximum productivity (14.9 g/m².d) were obtained in the first 9 d of microalgae growth. The maximum biomass concentration (1.64 g/L) was obtained in 37 d of cultivation. The highest levels of carbohydrates, proteins and lipids in the biomass were 10.6, 57.0 and 11.7%, respectively. The plant monitoring demonstrated that the microalgae produced biomass with high quality for application as biofuels, energy, health and nutrition human.

Extrato aquoso de C-ficocianina de Spirulina platensis, com e sem resíduos celulares, foi purificado em sistema aquoso bifásico (SAB) polietilenoglicol (PEG)/fosfato de potássio variando-se a massa molar do PEG, a pH 6, mais promissor do que a pH 7. Para os ensaios realizados com cada massa molar, com diferentes percentuais de PEG e sal, as concentrações (mg mL-1), as purezas (OD 620/OD 280) e os coeficientes de partição da C-ficocianina de cada sistema foram determinados e comparados. O processo para a purificação primária de C-ficocianina intracelular com resíduos celulares (integrado), composto por 15% de PEG 1500 e 13% de fosfato de potássio de 5% de PEG 4000 e 18% de sal, alcançaram concentrações de C-ficocianina de, respectivamente, 1,60 e 2,67 mg mL-1 na fase de topo. As purezas foram de 0,73 e 0,79, respectivamente, valores superiores aos obtidos nos sistemas sem resíduos celulares.

Crude C-phycocyanin extracts from Spirulina platensis, with and without cell debris, were purified in aqueous two-phase systems ( ATPS) varying the molar mass of the PEG, at pH 6, more promising than at pH 7 . For the assays carried out with each molar mass, with distinct percentages of PEG and salt, the concentrations (mg mL-1), purities (OD 620/OD 280) and C-phycocyanin partition coefficients of each system were determined and compared. The process for the primary purification of intracellular C-phycocyanin with cell debris (integrated), composed of 15% of PEG 1500 and 13% of potassium phosphate and 5% of PEG 4000 and 18% of salt, produced C-phycocyanin concentrations of, respectively, 1.60 and 2.67 mg mL-1 in the top phase. The purities were of 0.73 and 0.79 respectively, values higher than those obtained in the systems without cells.