Avaliação da fração volátil de Phormidium autumnale em biorreatores heterotróficos

Abstract

The microalgae are a source of potential commercial interest biomolecules due to its diverse metabolic profile able to synthesize different classes of organic compounds. The Phormidium gender is a cyanobacterium with growth ability in heterotrophic cultures by the addition of an exogenous source of carbon. Aiming at the possibility of recovery of byproducts generated in heterotrophic microalgal bioreactors, this study aimed to identify and quantify the volatile organic compounds in Phormidium autumnale crops. In the first stage we evaluated the qualitative profile of volatile organic compounds formed in heterotrophic cultures supported with glucose at 72 h experiment. We identified 54 compounds classified as alcohols (27%), ketones (23%), aldehyde (19%), ester (14%), acid (3.5%) and hydrocarbons (2.6%). In the second study we determined the qualitative and quantitative profile of volatile compounds formed in heterotrophic cultivation of 144h. In total 68 compounds were identified and quantified in cultures supported by glucose or fructose. The 3-methyl-butanol compounds was identified between the main 141.5μg.mg-1 in the culture of glucose and in the culture of fructose 69.5μg.mg-1. Many compounds identified during heterotrophic culture derived from metabolic pathways such as the terpene (β-ionone, β-cyclocitral and 5,6-epoxy-β-ionone), of the fatty acids (hexanol, hexanal) or the 2-keto acids (3-methyl-butanol, propanol, butanol). The results helped to elucidate a fraction of biocompounds microalgal with great potential for commercial exploitation.