RESUMO
The objective of this study was to cultivate Chlorella fusca LEB 111 with nanofibers indoors and outdoors to verify the effect on CO2 biofixation and macromolecule production. The microalgae were cultured with 10% (w v-1) polyacrylonitrile (PAN)/dimethylformamide (DMF) nanofibers containing 4% (w v-1) iron oxide nanoparticles (NPsFe2O3), which were added to the cultivations at concentrations of 0, 0.1, 0.3 and 0.5 g L-1. The CO2 biofixation was higher in outdoor assays (270.6 and 310.9 mg L-1 d-1) than in indoor assays (124.6 and 131 mg L-1 d-1) with 0.1 and 0.3 g L-1 nanofibers, respectively. The outdoor assays with 0.3 g L-1 nanofibers had 10.9% greater lipid production than the assays without nanofibers. Thus, this first study of outdoor cultivations with nanofibers as physical adsorbents of CO2 showed the effect of nanostructures in maximizing gas biofixation and producing biomolecules that can be used to obtain bioproducts.
Assuntos
Ciclo do Carbono , Dióxido de Carbono/metabolismo , Chlorella/fisiologia , Nanofibras/química , Polímeros/química , Biomassa , Concentração de Íons de Hidrogênio , Microalgas , TemperaturaRESUMO
The concentration of carbon dioxide (CO2) in the atmosphere has increased from 280 to 400 ppm in the last 10 years, and the coal-fired power plants are responsible for approximately 22 % of these emissions. The burning of fossil fuel also produces a great amount of solid waste that causes serious industrial and environmental problems. The biological processes become interesting alternative in combating pollution and developing new products. The objective of this study was to evaluate the CO2 biofixation potential of microalgae that were grown using gaseous effluents and solid residues of thermoelectric origin. The microalgae Chlorella fusca LEB 111 presented higher rate of CO2 biofixation (42.8 %) (p < 0.01) than did Spirulina sp. LEB 18. The values for the CO2 biofixation rates and the kinetic parameters of Spirulina and Chlorella cells grown using combustion gas did not differ significantly from those of cells grown using CO2 and a carbon source in the culture media. These microalgae could be grown using ash derived from coal combustion, using the minerals present in this residue as the source of the essential metals required for their growth and the CO2 derived from the combustion gas as their carbon source.