Prospecção de metabólicos secundários produzidos por fungos marinhos com atividade antifúgica

Abstract

The marine environment has become promising in the search for chemical substances with biotechnological, pharmaceutical and agricultural potential. These complex substances are often produced by microorganisms associated with marine invertebrates (corals and sponges), especially filamentous fungi. This group of microorganisms has shown potential because they have peculiar biochemical routes capable of synthesizing characteristic or species-specific metabolites. These natural products provide antifungal, antimicrobial, antioxidant, anti-inflammatory, antiviral properties, among others. Therefore, the objective of this work was to make a systematic review on marine fungi and secondary metabolites with biological activities and to investigate the biotechnological potential of filamentous fungi associated with marine invertebrates in Maceió / AL with antifungal activity against infectious agents. The systematic review was carried out by searching for keywords such as “marine fungi”, “antifungal”, “secondary metabolite” and “natural products” in the Pubmed and Science Direct databases, obtaining 19 articles published between the years 2015 and 2020 that describe 84 metabolites produced by marine fungi. The biotechnological potential was verified from the production of crude extracts from 16 fungi, collected in the coral reef of Praia de Ponta Verde, Maceió-AL. To obtain the fungal extracts, they were grown. After cultivation of 7 days in Potato Dextrose Agar (BDA), followed by a second cultivation of 14 days in liquid medium composed of 1% glucose, 0.1% yeast extract, 0.1% potassium chloride, sodium chloride 0.1%, the fungi supernatant and mycelium were extracted with ethyl acetate, generating an organic and aqueous fraction. Subsequently, they were analyzed using the Minimum Inhibitory Concentration Determination (MIC) technique to analyze the sensitivity of microorganisms to antimicrobials. Crude extracts from ten marine fungi showed antifungal activity against the yeast Candida haemulonii, five against Candida albicans, two against Cryptococcus gatti and 10 against Cryptococcus neoformans. Two of the extracts of the active fungi were fractionated with methanol, acetonitrile and water and tested again by the CIM method. The fungi C. neoformans ATCC 40283 and C. albicans ATCC 90028 were inhibited by all tested fractions, presenting MIC between 0.5-2.0 μ/mL, demonstrating that the bioactive compounds derived from marine microorganisms have antimicrobial and biotechnological potential.