Analysis of Surfactant Micellers and Their Interaction with Enzymes by Fluorescence of Pyrene

The characteristics of four different surfactant(RL(rhamnolipid),SDS,CTAB and Tween 80) micellers and their interaction with cellulase and laccase were investigated by fluorescence of pyrene,an extrinsic fluorescent probe.The results showed that the fluorescent behaviors of pyrene in these four surfactant solutions are different,in the same condition of each surfactant series concentration at 0.01 CMC(critical micelle concentration) to 4 CMC.Because the pyrene fluorescence intensity can be affected by the surfactant property,surfactant concentration and the fluorescence quenching factors,the hydrophobic adsorption of cellulase on surfactant molecules and pyrene resulted in the decrease of I1/I3 value of pyrene fluorescence.While in the presence of laccase,the I1/I3 values were maintained because of the laccase′ better hydrophilicity,though the fluorescent intensity decresed markedly as the copper ions disturbed.When the surfactant concentration is above the CMC,the stability of the enzymes entrapped in rhamnolipid biosurfactant micelles seems better than that in the SDS systems.