title: Factors influencing the trans-membrane transport ofn-octadecane byPseudomonassp. DG17.
abstract: In soil bioremediation techniques, the trans-membrane transport of hydrocarbons across the cell membrane is a new and complex point of understanding the process of hydrocarbons biodegradation. In this study, the effect of different environmental factors, including substrate concentration, bacterial inoculums, pH, salinity, substrate analogues and nutrients, on the transport of [14C]n-octadecane byPseudomonassp. DG17 was investigated. The results showed that cellular [14C]n-octadecane levels increased along with the increase in the substrate concentration. However, the trans-membrane transport of [14C]n-octadecane was a saturable process in the case of equal amounts of inoculum (biomass). The highest concentration of accumulated [14C]n-octadecane was 0.51 μmol mg-1± 0.028 μmol mg-1after incubation for 20 min. Meanwhile, the cellularn-octadecane concentration decreased along with the biomass increase, and reached a stable level. Acidic/alkaline conditions, high salinity, and supplement of substrate analogues could inhibit the transport of [14C]n-octadecane byPseudomonassp. DG17, whereas nitrogen or phosphorus deficiency did not influence this transport. The results suggested that trans-membrane transport of octadecane depends on both the substrate concentration and the microorganism biomass, and extreme environmental conditions could influence the biodegradation ability of microorganisms through inhibiting the transport of extracellular octadecane.
authors.affiliation: Department of Water Ecology and Environment, College of Water Sciences, Beijing Normal University , Beijing , China.
authors.forename: Fei
authors.initials: F
authors.lastname: Hua
authors.affiliation: Department of Water Ecology and Environment, College of Water Sciences, Beijing Normal University , Beijing , China.
authors.forename: Hong Qi
authors.initials: HQ
authors.lastname: Wang
authors.affiliation: Department of Water Ecology and Environment, College of Water Sciences, Beijing Normal University , Beijing , China.
authors.forename: Yi Cun
authors.initials: YC
authors.lastname: Zhao
keywords: Pseudomonas; biodegradation; environmental factors; octadecane; trans-membrane transport