Biorrefinaria de microalgas: produção de químicos de alto valor a partir de efluentes agroindustriais

Abstract

Cyanobacteria are prokaryote microorganisms that gather interesting features for the biotechnological use in biorefinery systems. Phormidium sp. is a cyanobacterium that has metabolic versatility, grown in both photosynthetic and heterotrophic conditions, from industrial residues, generating a chemically attractive biomass. On face of it, the work aimed to evaluate the production of high added value chemicals by Phormidium sp. from agro-industrial residues. It focuses on (i) identification and quantification of carotenoids from heterotrophically grown biomass in agro-industrial wastewater (ii) identification and quantification of carotenoids from photoautotrophically grown biomass and evaluation of the antioxidant capacity of the extract (iii) quantification of phycobiliproteins from photoautotrophically grown biomass and evaluation of the antioxidant capacity of the extract (iv) quantification of chlorophyll from photoautotrophically grown biomass and the evaluation of the antioxidant capacity of the extract. The results showed that the microalgal biomass from heterotrophic growth had 183.03 ± 0.9 g.g-1 of total carotenoids while in the biomass from photosynthetic growth this value was 714.3 ± 0.9 g.g-1. The major carotenoids in both extracts were all-trans--carotene, all-trans-lutein and all-trans-zeaxanthin. The carotenoid extract was able to scavenge the peroxyl radical 28 times more than the -tocopherol standard. The content of phycocyanin found was 20.05 ± 1.1 g.100g-1 and after fractionation achieved a purity ratio of 4.8 as well as antioxidant capacity of 237.4 ± 0.7 mol trolox equivalents.g-1. In terms of chlorophyll, the biomass showed the content of 3400 g.g-1 and the capacity to scavenge the peroxyl radical 84.9 in relation to -tocopherol standard. The results show that Phormidium sp. microalgal biomass has potential for biotechnological exploitation as a renewable and low cost source of bioactive compounds of high added value.