title: Biosurfactant production and its effects on solubilization activity of phenanthrene: a longitudinal study.
abstract: Pseudomonas facilis and Pseudomonasspp., isolated on the basis of its ability to grow on polycyclic aromatic hydrocarbon, was assayed for biosurfactant production (BP) potentials by measuring the surface tension (ST) of the culture supernatant at different time intervals. The strains in three levels of initial inoculum size (OD600 nm = 0.5, 1, 1.5) were added to medium to determine if bacterial inoculum size affects solubilization of phenanthrene (PHE).The result showed that although the two strains reduced the mean ST to less than 34.12 mN m(-1) at the end of day 6, mean solubilization activity of PHE reached 77.05 mg L(-1) on the sixth day. There was a significant increase in BP over time (P = 0.008); reaching its peak, 157.84 mg L(-1), at the end of the sixth day. Mean solubilization activity of PHE was not significantly different for the two strains (P = 0.216). The time-course study revealed that the ST reduction and BP potential was enhanced as inoculation size increased, leading to higher PHE solubility during the incubation time. However, the trend of increase in PHE solubility was not totally in the same way to cell growth and BP. It may be suggested that more bacterial density needs to be inoculated for practical application of effective bioremediation.
authors: Department of Environmental Health Engineering, School of Health, Student Research Committee, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran.
authors: Masoumeh
authors: M
authors: Golshan
authors: Modeling in Health Research Center, Institute for Futures Studies in Health, Kerman University of Medical Sciences, Kerman, Iran.
authors: Maryam
authors: M
authors: Dastoorpour
authors: Department Research Center for Environmental Health Technology (RCEHT), Iran University of Medical Sciences, Tehran, Iran E-mail: rezaei.r@iums.ac.ir.
authors: Roshanak Rezaei
authors: RR
authors: Kalantary
mesh_terms: D001673:Biodegradation, Environmental; D020563:Gammaproteobacteria / Q000378:metabolism*; D008137:Longitudinal Studies; D010616:Phenanthrenes / Q000737:chemistry / Q000378:metabolism*; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry / Q000378:metabolism*; D011549:Pseudomonas / Q000378:metabolism*; D012995:Solubility; D013501:Surface-Active Agents / Q000737:chemistry / Q000378:metabolism*
chemical_list: D010616:Phenanthrenes; D011084:Polycyclic Aromatic Hydrocarbons; D013501:Surface-Active Agents; C031181:phenanthrene