Biotransformação de gingeróis por fungos endofíticos

Abstract

Biotransformation is a process that involves chemical conversions catalyzed by enzymes. Endophytic fungi are microorganisms capable of producing enzymes and metabolites of great biotechnological interest, so they are quite employed in these processes. Zingiber officinale presents phenolic compounds with important proven pharmacological activities. In this way, the objective of this work was to evaluate the biotransformation potential of the endophytic fungi Curvularia asianensis and Hawksworthiomyces sp. isolated from the Humirianthera ampla plant in front of the isolated gingerols of Zingiber officinale. The fungal strains underwent an identification process and their genetic material was extracted, amplified, sequenced and analyzed by a phylogenetic study. Subsequently, some growth conditions were tested in Petri dishes, where the growth medium, temperature and incidence of luminosity were evaluated. In the biotransformations two experiments were carried out in sequence, where some parameters were tested: substrate (fraction enriched with gingerols and 6-gingerol alone); different liquid culture media (dextrose potato - BD, sabouraud dextrose - SBD and meat and peptone extract - MEP) and different days of experiment (7, 8, 9, 10 and 14 days). 25 µL of each substrate dissolved in the solvent was used in the co-solvent dimethylsulfoxide (DMSO) at 4% concentration and liquid-liquid partition with 1 mL of ethyl acetate for completion of the procedures. The extracts obtained from the biotransformations were analyzed by analytical thin layer chromatography (ADCC). The fungi were identified as Curvularia asianensis and Hawksworthiomyces sp., the latter being a probable new species of the genus. For the C. asianensis fungus, the formation of more polar compounds than those of the enriched fraction in all the liquid media tested was observed in ADCC, whereas with the 6-gingerol isolate in SBD the same change was evidenced from the 7th day of experiment. Already for Hawksworthiomyces sp. in its chromatographic profile the formation of more polar compounds than those of the enriched fraction was observed only liquid media SBD and BD, whereas with the 6-gingerol isolate the same result was evidenced in SBD medium only on the 8th day of experiment. This work has an unprecedented character since there are no papers in the literature about isolation and identification of the endophytic fungi from H. ampla nor the use of them in biotransformation processes.