Characterization of Biosurfactant Production and Cell Surface Properties of Five Effective Yeast Strains in PAHs Biodegradation

摘要

The objectives of this work were comparison of biosurfactant production and cell surface properties' changes of five effective yeast isolates when PAH was used as carbon source,as well as the assessment of PAHs degradation efficiency of these yeast strains.A two-phase culture system was used to analyze phenanthrene solubility and its absorbance to biomass in these yeast cultures.The results showed that these isolates were better emulsifier producers than surface tension reducers when naphthalene was used as carbon source.During growth on PAHs,an important increase in cell surface hydrophobicity and emulsification activity was observed.The results of the two-phase system suggested that the yeast strains with stronger emulsification ability possessed the ability to increase the aqueous solubility of PAHs,and the strains with higher cell hydrophobicity adsorbed much more phenanthrene on cell surface.This result suggested that both emulsifier production and cell surface hydrophobicity could promote hydrocarbon uptake.The higher degree of PAHs biodegradation was corresponded to the high emulsification activity of yeast strains.Based on the results,it is supposed that emulsification activity might play an important role in PAHs degradation by these yeast strains.