Potencial biotecnolÃgico de Candida lipolytica na produÃÃo de biossurfactantes, nos processos de remoÃÃo e biossorÃÃo do pireno (derivado do petrÃleo)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2004

RESUMO

In previous studies Candida lipolytica IA1055 has shown excellent potential in biosurfactant production, demonstrating emulsifying ability in low-cost culture media. Taking that into consideration, investigations were performed utilizing low-cost culture media in basal seawater supplemented with babassu oil and glucose as control of carbon sources. The highest biosurfactant production was observed in media Yeast Salt Water â Babassu (YSW-B2) and Yeast Salt Water â Babassu (YSW-B3), in which the molecules produced showed excellent emulsification activity. These molecules were considered new bioemulsifiers, chemically consisting of carbohydrate, protein and lipid. After media selection, a two-level factorial design with five factors (yeast extract, ammonium sulfate, urea, potassium phosphate and babassu oil) was performed, in order to test their influence over biosurfactant production, through statistically combined effects. The results suggested that higher production occurred with yeast extract, urea and potassium phosphate in their highest levels, and ammonium in its lowest level. As for the carbon source (babassu oil), the results indicated that its level was independent to the biosurfactant production. The culture media conditions, selected by the factorial design, were used to perform studies with mixed substrates (soluble and insoluble) for the processes of removal and biosorption of pyrene (petroleum derivative) using five different culture media. The results of High Performance Liquid Chromatography (HPLC) analyses demonstrated a high removal rate of pyrene in media I and IV with 99.02% and 97.51% percentage, respectively. Subsequential studies were performed with the biosorption of pyrene utilizing Candida lipolytica immobilized biomass in polyvynil alcohol as inert matrix. Biomass concentrations (100, 200 and 300 mg) were immobilized and packed in columns for evaluation of pyrene biosorption process. The eluents (ethyl acetate and water) and the fractions obtained were analyzed by HPLC.The results obtained suggested that the Candida lipolytica immobilized biomass presented great potential in pyrene biosorption processes because of its low cost. The results indicated that the maximum biosorption capacity of pyrene was 86.91 , 44.62 and 29.43 mg l-1 respectively for the 100 mg, 200 mg and 300 mg colunms

ASSUNTO(S)

candida lipolytica petrÃleo potencial biotecnolÃgico micologia biossurfactantes

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