Pyrene was initially adsorbed by B. brevis and subsequently
transported across the plasma membrane into the cell. Then, part
of pyrene was degraded under the action of related enzymes, yet
another small part of it still accumulated intracellularly. During
this process, pyrene removal was primarily dependent on biodegradation.
Although the presence of pyrene affected surface morphology
of cell, B. brevis could utilize pyrene as carbon source for
growth, and cells regrew after 96 h. Moreover, proportion of necrotic
cells in pyrene containing system was only 2.8% after 120 h,
and cell size and intracellular particle density changed, due to the
influence of contaminant.