BIOSSORÇÃO DE CÁDMIO E PRODUÇÃO DE BIOSSURFACTANTES POR FUNGOS FILAMENTOSOS EM FERMENTAÇÃO SUBMERSA

The removal of metals using selected microorganisms has made promising, since they present high select ivity and rate of removal. The aim of this work was to ev aluate the removal of cadmium via submerged bioprocess for filamentous fungi. The microorganisms used were filamentous fungi of the genus Aspergillus spp, identified by O-3 and O-8, and of the genus Trichoderma sp, identified as E-19. The culture medium was composed of 10% wheat bran, 10% of saline solution with micronutrients, 4.5% of yeast extract, 2% of soybean oil a nd 10 mg/L or 20 mg/L of cadmium. The experiments were performed in erlenmeiers at 30° C for 7 d in a shaker . Aliquots were collected at beginning and end of the bioprocess for the determination of metal removal. Sampling at 0, 1, 2, 3, 5 and 7 d were performed to determine the emulsifying activity of the media, w hich indicates the production of biosurfactants by micro organisms. The Aspergillus strains showed 100% removal of the metal added to the culture medium in submerged fermentation, superior than Thrichoderma (O-3 and O-8) removals (46-49%). During the process of biosorptio n, we observed the production of biosurfactants by the microorganisms studied, demonstrating the importance of these compounds in the process of removal of metals from liquid media.