The mechanism of transport of C-14-fluoranthene by Rhodococcus sp. BAP-1, a Gram-positive bacterium isolated from crude oil-polluted soil, was examined. Our finding demonstrated that the mechanism for fluoranthene travel across the cell membrane in Rhodococcus sp. BAP-1 requires energy. Meanwhile, the transport of fluoranthene involves concurrent catabolism of C-14, that leading to the generation of significant amount of (CO2)-C-14. Combined with trans-membrane transport dynamic and response surface methodology, a significant influence of temperature, pH and salinity on cellular uptake rate was screened by Plackett-Burman design. Then, Box-Behnken design was employed to optimize and enhanced the trans-membrane transport process. The results predicted by Box-Behnken design indicated that the maximum cellular uptake rate of fluoranthene could be achieve to 0.308 mu mol min (1) mg (1).protein (observed) and 0.304 mu mol min (1) mg (1).protein (predicted) when the initial temperature, pH and salinity were set at 20 degrees C, 9% and 1%, respectively. (C) 2014 Elsevier Ltd. All rights reserved.