The cell wall-cosolvent partition coefficients (K(m)) of polycyclic aromatic hydrocarbons (PAHs) were determined for Rhizopus oryzae cell walls by controlling the volume fraction of methanol (f) ranging from 0.1 to 0.5. Five cosolvent models were employed for extrapolating the cell wall-water partition coefficients (K(w)) in pure water. The extrapolated K(w) values of four PAHs on R. olyzae cell walls were ranged from 2.9 to 5.1. Comparison of various K(w) values of pyrene generated from extrapolation and the QSPR model, together with predicted different (PD), mean percentage deviations (MPD), and root mean square errors (RSE), revealed that the performance of the LL and Bayesian models were the best among all five tested cosolvent models. This study suggests that K olyzae cell walls play an important role in the partitioning of PAHs during bioremediation because of the high K(w) of fungal cell walls. (C) 2011 Elsevier Ltd. All rights reserved.