Biosurfactant-assisted bioremediation of crude oil by indigenous bacteria isolated from Taean beach sediment

• Published in: Environmental pollution (1987) 2018-10, Vol.241, p.254-264
• Main Authors: Lee, Dong Wan, Lee, Hanbyul, Kwon, Bong-Oh, Khim, Jong Seong, Yim, Un Hyuk, Kim, Beom Seok, Kim, Jae-Jin
• Format: Article
• Language: English
• Subjects: Bacillus - metabolism; Bacteria - metabolism; Biodegradation, Environmental; Biosurfactant-producing bacteria; Desorption; Geologic Sediments - chemistry; Geologic Sediments - microbiology; Glycolipids; Hydrocarbons - metabolism; Microorganism; PAHs; Petroleum - analysis; Petroleum Pollution - analysis; Rhamnolipid; Spectroscopy, Fourier Transform Infrared; Surface-Active Agents - chemistry; Taean oil spill
• ISSN: 0269-7491; 1873-6424
• DOI: 10.1016/j.envpol.2018.05.070

Crude oil and its derivatives are considered as one group of the most pervasive environmental pollutants in marine environments. Bioremediation using oil-degrading bacteria has emerged as a promising green cleanup alternative in more recent years. The employment of biosurfactant-producing and hydrocarbon-utilizing indigenous bacteria enhances the effectiveness of bioremediation by making hydrocarbons bioavailable for degradation. In this study, the best candidates of biosurfactant-producing indigenous bacteria were selected by screening of biochemical tests. The selected bacteria include Bacillus algicola (003-Phe1), Rhodococcus soli (102-Na5), Isoptericola chiayiensis (103-Na4), and Pseudoalteromonas agarivorans (SDRB-Py1). In general, these isolated species caused low surface tension values (33.9–41.3 mN m−1), high oil spreading (1.2–2.4 cm), and hydrocarbon emulsification (up to 65%) warranting active degradation of hydrocarbons. FT-IR and LC-MS analyses indicated that the monorhamnolipid (Rha-C16:1) and dirhamnolipid (Rha-Rha-C6-C6:1) were commonly produced by the bacteria as potent biosurfactants. The residual crude oil after the biodegradation test was quantitated using GC-MS analysis. The bacteria utilized crude oil as their sole carbon source while the amount of residual crude oil significantly decreased. In addition the cell-free broth containing biosurfactants produced by bacterial strains significantly desorbed crude oil in oil-polluted marine sediment. The selected bacteria might hold additional capacity in crude oil degradation. Biosurfactant-producing indigenous bacteria therefore degrade crude oil hydrocarbon compounds, produce biosurfactants that can increase the emulsification of crude oil and are thus more conducive to the degradation of crude oil. [Display omitted] •Bioremediation using oil-degrading bacteria is a promising green cleanup alternative.•BS-producing indigenous bacteria were selected by screening of biochemical tests.•Various rhamnolipids were produced by the bacteria as potent biosurfactants.•The production of BSs (rhamnolipids) by the bacteria may affect the degradation of crude oil.•Biosurfactants significantly desorbed crude oil in oil-polluted marine sediment. Biosurfactant-producing indigenous bacteria can effectively expedite the bioremediation of crude oil contaminated environments.