RESUMO
BACKGROUND: The present study describes the production of biosurfactant (BS) and emulsifier (BE) by the filamentous fungus Mucor hiemalis UCP 0039, as well as the characterization and stability of the both biomolecules for environmental or industrial applications. RESULTS: Biosurfactants and bioemulsifiers are amphiphilic compounds and are produced as extracellular molecules. The results showed that bioproduct obtained by shaker condition reduced the water surface tension of 72 to 32 mN/m and reached an emulsification index of 96%, while the static cultivation resulted in a biomolecule with a surface tension of 40 mN/m and an emulsification index of 96%, suggesting the production of a biosurfactant and bioemulsifier, respectively. The compounds showed glycolipid nature but the biosurfactant presented cationic charge, while the bioemulsifier, anionic charge. Thus, the results confirmed that M. hiemalis produced two distinct biomolecules under different parameters and in the same culture medium. CONCLUSIONS: It is the first time that biosurfactant and emulsifier production has been described in the same medium and under different physical conditions by Mucor hiemalis. Both biomolecules showed thermal stability, as well as have significant effect on the viscosity of hydrophobic compounds, indicating the excellent potential for environmental safety or industrial applications to improve the efficiency of sustainable and economic technologies.
Assuntos
Tensoativos/metabolismo , Emulsificantes/metabolismo , Mucor/metabolismo , Solo , Tensoativos , Óleo de SojaRESUMO
The automated Bioscreen C system was used for growth of four Mucor hiemalis strains isolated from the soil in the Juréia-Itatins Ecology Station (JIES), São Paulo state, in liquid culture media containing different carbon (2%) and nitrogen (1%) sources, pH 5.0, at 25ºC, and agitated at 150 rpm for 5 days. The medium containing only one nitrogen source had been added with 2% glucose. The readings were taken at lambda = 540 nm, at 2-hour intervals, up to five days. The results were compared using the Friedman Test (alpha = 5%). The best growth was obtained for strains M1, M2 and M3, reaching the log phase in 60 hours. The best carbon sources varied according to the strain, and yeast extract proved to be the best nitrogen source. Sodium acetate inhibited the growth of the four strains, being the M3 strain the most affected. The use of the automated system was very convenient for cultures in liquid media, as it is rapid and automated, providing a good technique for determination of the optimal environmental factors for growth of the filamentous fungi.
O sistema automatizado Bioscreen C foi utilizado para o crescimento de quatro linhagens de Mucor hiemalis, isoladas do solo da Estação Ecológica de Juréia-Itatins (EEJI), estado de São Paulo, em meios líquidos com uma única fonte de carbono (2%) ou de nitrogênio (1%), pH 5,0, a 25ºC, e agitação de 150rpm por 5 dias. O meio com somente uma única fonte de nitrogênio foi adicionado com 2% de glicose. As leituras de densidade óptica foram realizadas a 540nm, em intervalos de 2h, por cinco dias. Os resultados foram analisados estatisticamente com o Teste de Friedman (alfa = 5%). Os melhores crescimentos foram obtidos com as linhagens M1, M2 e M3, que atingiram o início da fase log em 60 horas de cultivo. As melhores fontes de carbono variaram de acordo com a linhagem estudada, e extrato de levedura provou ser a melhor fonte de nitrogênio para todas as linhagens. Acetato de sódio inibiu o crescimento das quatro linhagens, sendo a M3 a mais afetada. O uso do sistema automatizado foi muito conveniente para as culturas em meio liquido, sendo rápido e automático, constituindo em uma boa técnica para a determinação das condições ambientais ótimas para crescimento de fungos filamentosos.