N-limited stationary cultures of the white rot fungi Phanerochaete chrysosporium, Trametes versicolor, and Coriolopsis polysona mineralized 1.393 +/- 0.353 (0.301 +/- 0.023) and 0.398 +/- 0.061 (0.112 +/- 0.010), and 0.015 +/- 0.004 (0.002 +/- 0.0008) % of the originally supplied 30.14 nmol (513.7 nmol) of 3,3',4,4'-tetrachloro(U-C-14]biphenyl (PCB 77) during 4 weeks. The extent of PCB 77 degradation was followed by C-14-radioactivity partitioning into aqueous, organic soluble, biomass associated, aqueous (intracellular) and organic soluble (intracellular) fractions. After four weeks incubation the pattern of distribution of radioactivity was similar in P. chrysosporium and C. polysona at-higher dose but not at the lower dose of PCB 77. T. versicolor differed in the distribution pattern of radiolabel.