The ability of Lentinus tigrinus to grow and to degrade persistent aromatic hydrocarbons in aged contaminated soil was assessed in this study. L tigrinus extensively colonized the soil; its degradation activity after 60d incubation at 28 degrees C, however, was mostly limited to dichloroaniline isomers, polychlorinated benzenes and diphenyl ether while the fungus was unable to deplete 9,10-anthracenedione and 7-H-benz[DE]anthracene-7-one which were the major soil contaminants. Although clean-up levels were limited, both density of cultivable heterotrophic bacteria and richness of the resident bacterial community in L tigrinus microcosms (LtM) increased over time to a significantly larger extent than the respective amended incubation controls (1.9 x 10(9) CFU g(-1) vs. 1.0 x 10(9) CFU g(-1) and 37 vs. 16, respectively). Naphthalene- and catechol 2,3-dioxygenase gene copy numbers, however, decreased over time at a higher rate in LtM than in incubation controls likely due to a higher stimulation on heterotrophs than xenobiotics-degrading community members. (C) 2010 Elsevier B.V. All rights reserved.