Biotransformação do sesquiterpeno β-cariofileno por fungos isolados do solo

Abstract

Microbial biotransformation of drugs and active natural compounds can be applied to modify chemical molecules of interest, enabling the generation of new compounds, increasing their pharmacological potential and reducing their toxicity. Several studies have shown the potential of biotransformation, often generating more active derivative compounds than the original molecule. As they are chemical alterations caused by enzymes, the biotransformation process is carried out in an aqueous medium, being considered less polluting than the conventional synthesis. The natural compound β-caryophyllene, found in plants, is known to have several biological activities, including antimicrobial activity. This work aimed to select soil fungi capable of biotransforming the natural compound β-caryophyllene. Soiland litter samples were collected, diluted and plated in two types of media, a complex medium containing rose bengal and a modified Czapek medium containing the compound. The plates were incubated at 27°C for 7 days, and the filamentous colonies were re-isolated. Biotransformation was performed in petri dishes containing modified Czapek agar medium, with 300 μg/mL of β-caryophyllene. The isolated fungi were seeded on the surface of the plate and these were incubated for 14 days at 27°C. Controls were carried out to evaluate the presence of metabolites of the fungus and possible modifications of the target molecule by the action of the culture medium and incubation characteristics, therefore, plates containing only the pure culture medium, only the medium and the drug, and only the medium and the fungus, were made for comparison. At the end of incubation, the agar was sectioned into smaller fragments, placed in an Erlenmeyer flask with 20 mL of ethyl acetate to extract the compounds present. Four isolates of filamentous fungi were obtained and one of them, obtained from the Czapek medium, showed promise for biotransformation of the β-caryophyllene test compound, being possible to visualize the presence of at least two different molecules, according to thin layer chromatography observations. Other studies will be carried out in order to identify the species of isolate and the chemical compounds observed.