Assessing adsorption of polycyclic aromatic hydrocarbons on Rhizopus oryzae cell wall components with water–methanol cosolvent model

• Adsorption of PAHs on fungal cell walls was determined in methanol–water cosolvent.
• Bound proteins influenced sorption behaviors of PAHs on cell wall components.
• Lipid adsorption was insufficient to evaluate the fate of PAHs adsorbed on fungal.
• Contribution of polysaccharide in PAHs adsorption on cell walls cannot be ignored.

The contribution of different fungal cell wall components in adsorption of polycyclic aromatic hydrocarbons (PAHs) is still unclear. We isolated Rhizopus oryzae cell walls components with sequential extraction, characterized functional groups with NEXAFS spectra, and determined partition coefficients of PAHs on cell walls and cell wall components with cosolvent model. Spectra of NEXAFS indicated that isolated cell walls components were featured with peaks at ~532.7 and ~534.5 eV energy. The lipid cosolvent partition coefficients were approximately one order of magnitude higher than the corresponding carbohydrate cosolvent partition coefficients. The partition coefficients for four tested carbohydrates varied at approximate 0.5 logarithmic units. Partition coefficients between biosorbents and water calculated based cosolvent models ranged from 0.8 to 4.2. The present study proved the importance of fungal cell wall components in adsorption of PAHs, and consequently the role of fungi in PAHs bioremediation.