Evaluation antimicrobial and antiadhesive properties of the biosurfactant lunasan produced by candida sphaerica UCP 0995

摘要

Different groups of biosurfactants exhibitdiverse properties and display a variety of physiologicalfunctions in producer microorganisms; these includeenhancing the solubility of hydrophobic/water-insolublecompound, heave metal binding, bacterial pathogenesis, celladhesion and aggregation, quorum sensing and biofilm formation.Candida sphaerica was grown in a low cost medium,consisting of distilled water supplemented with 9%refinery residue of soybean oil and 9% corn steep liquor, for144 h at 28 C and 150 rpm. The cell-free supernatantobtained at the end of the experiments was submitted toextraction, and afterward the biosurfactant was isolatedusing methanol with a yield of 9 g l-1. The critical micelleconcentration of the biosurfactant was found to be0.25 mg ml-1 with a surface tension of 25 mN m-1. Severalconcentrations of the biosurfactant (0.625–10 mg ml-1)were used to evaluate its antimicrobial and antiadhesiveactivities against a variety of microorganisms. The biosurfactantshowed antimicrobial activity against Streptococcusoralis (68%), Candida albicans (57%), and Staphylococcusepidermidis(57.6%) for the highest concentration tested.Furthermore, the biosurfactant at a concentration of10 mg ml-1 inhibited the adhesion between 80 and 92% ofPseudomonas aeruginosa, Streptococcus agalactiae,Streptococcus sanguis12. Inhibition of adhesion with percentagesnear 100% occurred for the higher concentrationsof biosurfactant used. Results gathered in this study point to apotential use of the biosurfactant in biomedical applications