Phenanthrene removal from liquid medium with emphasis on production of biosurfactant

In the current study, there are some considerable issues which focused on: (1) the production of biosurfactant, (2) its correlation with the initial bacterial inoculum in the liquid phase and (3) its effect on polycyclic hydrocarbon (PAH) bioremediation performance. Therefore, two strains Pseudomonas facilis and Pseudomonas spp. were able to form a large clear zone diameter on the oil surface. Phenanthrene (PHE) was also utilized as a sole substrate. Furthermore, biosurfactant production (BP) was detected by methylene blue analysis procedure and surface tension (ST) lowering. The capacity of these two strains to lower the aqueous ST was 29 and 30.7 from 72 mN m^-1 by 6 days for P. facilis and Pseudomonas spp., respectively. Higher initial bacterial inoculation led to an improvement in PHE removal (P < 0.0001). But there was no significant correlation between either PHE solubility or BP and the initial bacterial inoculation. The removal efficiency of 88.44% within 21 days confirms that the inoculation of P. facilis led to the considerable BP for removal of PAHs from contaminated water.