Estudo de bioactividades: herbicida no sumo de uva branca e antimicrobiana nos figos

Mestrado em Biologia Funcional - Instituto Superior de AgronomiaBioactive natural compounds may be valuable substitutes for nefarious phytochemicals. The herbicidal effect of white grape juice (Vitis vinifera L.) was studied by developing a sample “cleaning” procedure, separating and defining different classes of compounds with the aim of obtaining a hydrophilic fraction with enriched herbicidal activity. By conducting germination essays using Avena sativa L. and Nasturtium officinale W.T. Ainton seeds it was demonstrated that the osmotic pressure caused by glucose and fructose, was not primarily responsible for this activity, suggesting that white grape juice herbicidal activity probably derives from a synergetic effect between different compounds present in this fraction. Escherichia coli T. Escherich, Salmonella typhimurium Le Minor & Popoff, Pseudomonas aeruginosa Schroeter, Listeria monocytogenes Pirie, Bacillus subtilis Cohn, Staphylococcus aureus Rosenbach, Candida tropicalis Berkhout, Candida albicans Berkhout, Zygosaccharomyces bailii Barnett et al. e Botrytis cinerea Pers., were studied for the antimicrobial activity of figs’ (Ficus carica L.) (red and white) syconium plus achenes and epicarp extracts. The hydrophobic fraction extracts (specially, hexane and ethyl acetate) exhibited high antimicrobial activity. The hydrophilic fraction revealed a growth promoting effect on the majority of these microorganisms, inhibiting only the yeast Z. bailii’s growth. None of those fractions showed effect against B. cinerea