Estudo químico e da atividade antimicrobiana da macaúba [(Acrocomia aculeata (JACQ.) Lodd.ex mart. 1763)] e dos seus endofíticos

Abstract

The present work was performed with the objective to study the biotechnological potential of the palm tree macaúba [(Acrocomia aculeata (Jacq.) Lodd. Ex Martius.1763)]. The plant material was gently given by the Laboratory of Macaúba Processes from Federal University of Minas Gerais (UFMG). The samples of leaves were collected during periods of high and low rainfall, in the months from October to april and june to august, respectively. With the aim to investigate the diversity of endophytic fungi in macaúba leaves, 04 (four) collects were executed and the material was sterilized according procedure reported in the literature (DOBRANIC et al., 1995). The process of identification of the endophytic organisms was performed in accordance with the observation of the macroscopic characteristics (DOMSCH et al.1980), and microcultivation in blades (RIDELL, 1950). As a result, were obtained 04 (four) isolate fungi: Acremonium sp., Brachysporiella sp, Papulospora sp e Trichothecium sp. After this stage it was executed the study to identify the metabolites presents in the culture filtrate of the endophytic fungi Acremonium sp, using the spectroscopic technique of Nuclear Magnetic Ressonance - NMR. The metabolites identified were ethanol, alanine, acetone succinate, methanol and oxaloacetate. Additionally was carried out the extraction with ethyl acetate of the secondary metabolites presents in the filtrate, and the antimicrobial evaluation of the crude extract was determinated by the Minimal Inhibitory Concentration (MIC). The Gram positives bacteria the EtOAc extract showed moderate inhibitory activity for Staplylococcus aureus with MIC of 500 μg/mL and for Staphylococcus epidermides with MIC of 250 μg/mL. The Gram negative bacteria were presented a very high inhibitory activity for Salmonela entérica with MIC of 125 μg/mL and weak inhibitory acitivity for Pseudomonas aeruginosa with MIC of 1000 μg/mL. Equally was carried out antimicrobial evaluation for the ethanol extract of the leaves of macauba, showing weak inhibitory activity for Gram-positive Staphylococcus aureus with MIC of 1000 μg/mL and Gram-negative Pseudomonas aeruginosa with MIC of 1000 μg/mL, with the rest there was no inhibition. These results highlight the relevance and the necessity of more researches with macauba, specially with endophytic fungi, considering that the present work is inedit.