Characterization and Production of a Biosurfactant Viscosin from Pseudomonas sp. HN11 and its Application on Enhanced oil Recovery During oily Sludge Cleaning.

Abstract

Biosurfactants are renewable resources with versatile applications on environmental bioremediation and industrial processes. Pseudomonas species are one of the promising biosurfactant producers. However, besides rhamnolipids, little is known about Pseudomonas-derived biosurfactants on solubilization of polycyclic aromatic hydrocarbons (PAHs) and oily sludge treatment. In this study, Pseudomonas sp. HN11-derived biosurfactant was purified by chromatographic methods and was characterized as viscosin via bioinformatic analysis, spectrometric and spectroscopic analyses, Marfey's method and (C-H)α NMR fingerprint matching approach. Viscosin is a potent biosurfactant with critical micelle concentration of 5.79mg/L and is stable under various stresses. Moreover, viscosin was produced at 0.42g/L at 48h of liquid fermentation. Further data have shown that emulsifying agent viscosin is capable of promoting the solubilization of PAHs and displays enhanced oil recovery during oily sludge treatment. More specifically, viscosin has shown significantly enhanced solubilization on fluoranthene compared with control (0.04mg/L), 2.21mg/L and 1.27mg/L fluoranthene was recovered from 100mg/L and 200mg/L viscosin treatment, respectively. However, only 200mg/L viscosin has significantly enhanced the solubilization of phenanthrene (0.75mg/L) and benzo[a]pyrene (0.51mg/L) compared to each control (0.23mg/L for phenanthrene and 0.09mg/L for benzo[a]pyrene). Viscosin treatment of oily sludge (recovering of 0.58g oil) has shown a significant oil recovery compared to that of control (recovering of 0.42g oil). This study shows the great potential of viscosin-type biosurfactant on oily sludge treatment.