a b s t r a c t
Bioremediation is a popular approach used to abate polycyclic aromatic hydrocarbons (PAHs) in the
environment. A consortium of white-rot fungi (CW-1) isolated from wood pieces was used for studying
their potential of bioremediation of PAHs. Biosorption and biodegradation of PAHs by live and heatkilled
white-rot fungi (CW-1) were investigated to elucidate the bio-dissipation mechanisms of PAHs.
Sorption isotherms of naphthalene, acenaphthene, fluorene, phenanthrene and pyrene to heat-killed fungal
biomass were linear and non-competitive, indicating the primary mechanism of biosorption to be by
partition. The carbon-normalized partition coefficients (Koc) were linearly correlated with octanol–water
partition coefficients (Kow), i.e., log Koc = 1.13 log Kow −0.84 (n=5, r2 = 0.996). Biosorption and biodegradation
of phenanthrene and pyrene by live white-rot fungi were quantified. In 1 week, the removal
efficiency of phenanthrene (70–80%) and pyrene (90%) by live fungi from aqueous solution were comparable
to those by heat-killed fungi. However, approximately 40–65% of phenanthrene and 60–85% of
pyrene were still stored in organismal bodies. Biosorption might restrict biodegradation while nutrient
limitation and presence of a PAH mixture might stimulate biodegradation. The apparent partition
coefficients (K∗
d) in live fungal systems and the Kd of heat-killed fungi without biodegradation were compared,
and then the K∗
d/Kd ratios were employed to illustrate the relative contributions of biosorption
and biodegradation under different nutrient conditions