Atividades antimicrobiana e antioxidante dos extratos da microalga Chlorococcum elbense cultivada em fotobiorreator

Abstract

In the search for new biotechnological applications related to living organisms more sustainably, microalgae have been studied as promising organisms in the generation of high added value products and byproducts and can be applied in several areas of industry, such as food, cosmetics, bioremediation, among other areas. In this context, the main goal of this work to evaluate the antifungal, antibacterial, and antioxidant activities of the protein extract of the biomass of the microalgae Chlorococcum elbense. First, the microalgae cultivation was prepared in a planar photobioreactor for biomass accumulation. Analysis of the standard growth curve and chlorophyll content during cell growth were set to maintain constancy in the subsequent cultures. After obtaining the biomass, there was an elemental analysis microalgal, being observed the presence of 35,23% of total proteins in the composition of the biomass. It was also determined the concentration of total proteins of the crude extract (EB) through the precipitation by ammonium sulfate. Was observed the highest protein concentration (0,899 mg.mL-1) in the protein fraction of 40-60% (FrP40-60%). This fraction was used in the antifungal analyzes, in which there was the formation of inhibition halo against the fungi Colletotrichum musae, Candida albicans, Aspergillus niger and Aspergillus fumigatus. In the antibacterial analyzes, the FrP40-60% inhibited the growth of the species Staphylococcus aureus and Staphylococcus epidermidis, obtaining a minimum inhibitory concentration (MIC) of 6.25 mg.mL-1 and a minimum bactericidal concentration (MBC) ranging from 6.25 mg .mL-1 and 12.50 mg.mL-1, according to the tested species. The antioxidant analysis occurred with both EB and FrP40-60%, both presenting antioxidant activity in different concentrations of proteins, being the value resulting from EB superior to FrP40-60%.