红球菌BAP-1对荧蒽的跨膜运输过程

利用同位素示踪法对红球菌BAP-1跨膜运输¹⁴C-荧蒽的过程进行了研究.结果表明在有ATP抑制剂NaN₃的存在下，红球菌BAP-1细胞膜内所结合的¹⁴C-荧蒽含量几乎无变化.结合对微生物体内包涵体的观察，说明当有ATP抑制剂存在的情况下，荧蒽无法通过细胞膜进入到微生物的体内.这表明若是荧蒽无法通过跨膜运输进入到红球菌细胞内，就不能得到有效的生物降解.在不同的底物浓度条件下，微生物对¹⁴C-荧蒽的跨膜运输过程是主动运输过程；在一定底物浓度条件下，菌体膜结合污染物的量会在一定的条件下达到饱和.结合米氏方程分析了红球菌BAP-1对¹⁴C-荧蒽的跨膜运输动力学过程，结果表明底物¹⁴C-荧蒽与微生物之间一直保持较高的亲和力，较高的亲和体系有助于跨膜运输过程的顺利进行.

Study on the trans-membrane transport process of fluoranthene by Rhodococcus sp. BAP-1

Trans-membrane transport of ¹⁴C-fluoranthene by Rhodococcus sp. BAP-1 was investigated by using the isotope tracing technique. The results indicated that in the presence of ATP inhibitor such as NaN₃, there were no significant change on the content of ¹⁴C-fluoranthene in the cell pellet of Rhodococcus sp. BAP-1during the uptake process. Therefore, the results demonstrated that the biodegradation process would be strongly prevented if the fluoranthene could not travel across the cell membrane. Meanwhile, the results indicated that under different substrate concentrations, the transport process of ¹⁴C-fluoranthene was driven by a active transport mechanism following the intra/extra substrate concentration gradient. Also, the transport capacity of ¹⁴C-fluoranthene had no special relationship with the inoculum level. Michaelis-Menten equation was used to characterize the trans-membrane transport kinetics, according to the experimental results, pollutants might be growing as a confluent biofilm and the uptake system might have a high specific affinity, which would significantly promote the trans-membrane transport process.