• Journal of Soil and Groundwater Environment
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• v.15 no.4
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• pp.13-20
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• 2010

The purpose of this study was to develope the remediation method of contaminated soils with metals and petroleum. The diesel degrading strain was isolated and identified from the soil contaminated by petroleum at industrial sites. Diesel biodegradation experiment was performed by diesel degrading bacteria in both solution and soil slurry. Contaminated soils by Zn or As and diesel were treated consecutively by steam-vapor extraction, biodegradation, and acid washing. The strain was identified as Pseudomonas aeruginosa, and named as Pseudomonas aeruginosa TPH1. The optimal culture conditions of TPH1 were $20^{\circ}C$ and pH 7.0, 3% of diesel concentration. Biodegradation of diesel was performed using the separated strain in liquid medium, and 63% of diesel was degraded in 72 hours. And 52% of diesel was removed in the tested soils. In the treatment of contaminated soils with diesel and Zn or As, 29% ~ 44% of diesel was reduced by steamvapor extraction, 60% ~ 71% of diesel was removed after biodegradation. 47% of Zn and 96% of As were removed after acid(mixture of sulfuric and oxalic acids) washing. It is recommended that consecutive treatment method of steam-vapor extraction, biodegradation and acid washing is effective for remediation of complex contaminated soils with metals and petroleum.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.3
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• pp.148-156
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• 2006

Potential hydrocarbon degrading bacteria were screened from the site artificially polluted with 20,000 ppm of diesel. Among the isolates, two strains, SJD2 and SJD4, showed higher activities to degrade diesel on the Bushnell-Hass broth medium containing 2% of diesel. 16S rDNA sequence analysis revealed that SJD2 and SJD4 were Bacillus fusifomis and B. cereus, respectively. Both strains were found to grow in a wide range of temperature between $20^{\circ}C-55^{\circ}C$, with the best at $30^{\circ}C-37^{\circ}C$. This is the first report, as far as we know, that B. fusifomis is capable of degrading diesel. We hope that a new isolate, B. fusifomis, will efficiently conduct bioremediation at the contaminated sites with petroleum hydrocarbons.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.09a
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• pp.310-314
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• 2002

To investigate the effect of on-site bioremediation in soil that have been contaminated by hydrocarbon fuel spills, petroleum-degrading bacteria isolated from soil around petroleum chemical industry and microbial agents were constructed. We investigated biopiles for on-site bioremediation of soil contaminated (5000 mg per kg) with bunker A fuel in five independent lab-scale experiments. Five biopile units constituting the following treatments: (1) control with no nutrients and microbial agents (2) microbial agent M plus nutrients (3) microbial agent C plus nutrients (4) only microbial agent C (5) control with only nutrients. The results were highly different one another. After 30 days in treatments with optimal condition, total petroleum hydrocarbons were reduced to below 10 mg per kg of soil at the biopile units mixed with microbial agents, but control biopile units show that were reduced from 1,105 to 2,588 mg per kg of soil. Our results show that microbial agents at on-site bioremediation of fuel-contaminated soil is highly effective.

• KSBB Journal
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• v.14 no.6
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• pp.737-741
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• 1999

Phenanthrene degrading bacteria were isolated from the petroleum contaminated soil near an oil tank. Four of 15 strains decreased surface tension of culture broth of phenanthrene-containing minimal media. H6, one of the isolated bacteria decreased surface tension of culture broth below 33 dyne/cm during growth on glucose. H6 was identified as Bacillus subtilis and biosurfactant produced by H6 was lipopeptide. The biosurfactant was produced at 0.13 g/L in the mineral medium containing 2% glucose. Critical micelle concentration(CMC) of the biosurfactant was 52 mg/L. Foaming power was similar to Tween 80 and dispersing power was superior to Tween 80m SDS and Brij30. High thermal stability and emulsion index were also observed.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.363-367
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• 2003

Batch experiments were performed to determine optimum conditions for biopile. The batch experiments results showed that 12.5 to 17.9% of moisture content was effective to biodegradation of petroleum hydrocarbon regardless of soil texture. Total heterotrophic bacteria populations in the inoculum-treated soil were greater than of the control and nutrient-amended soil in the early stage, but the populations in the inoculum and nutrient-amended soil were not different significantly from those in the latter stage regardless of soil texture. The same trend was observed for petroleum hydrocarbon degrading bacteria populations. The results of the biodegradation capacity experiments showed that there was a decline in the TPH concentrations during the experiments and no significant difference on the biodegradation was observed by treatment in silt soil. Changes of n-C17/pristane and n-C18/phytane ratios in all treated soil were significantly more than those of control. This is a strong indication of biodegradation. The TPH removal rate was calculated at 60% in all treated soil.

• Journal of Life Science
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• v.21 no.11
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• pp.1599-1606
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• 2011

To evaluate the effects of microorganism agents on oil biodegradation, treatability and microcosm studies were conducted. Petroleum oil degrading bacteria were isolated from enriched cultures of oil-contaminated sediment samples using a mineral salts medium (MSM) containing 0.5% Arabian heavy crude oil as the sole carbon source. After a 5 day-incubation period using MSM, mixed microorganisms of three species (strains BS1, BS2 and BS4) degraded 48.4% of aliphatic hydrocarbons and 30.5% of aromatic hydrocarbons. Treatability and microcosm tests were performed in the three different treatment conditions (AO: Arabian heavy crude oil, AO+IN: Arabian heavy crude oil+inorganic nutrient, AO+IN+MM: Arabian heavy crude oil+inorganic nutrient+mixed microorganism agents). Among these, significantly enhanced biodegradation of aliphatic hydrocarbons were observed in AO+IN and AO+IN+MM conditions, without showing any different biodegradation rates in either condition. However, the degradation rates of aromatic hydrocarbons in an AO+IN+MM condition were increased by 50% in the treatability test and by 13% in the microcosm test compared to those in an AO+IN condition. Taken together, it can be concluded that mixed microorganism agents enhance the biodegradation of aliphatic and aromatic hydrocarbons in laboratory, a treatability test, and a microcosm test. This agent could especially be a useful tool in the application of bioremediation for removal of aromatic hydrocarbons.

• Journal of Soil and Groundwater Environment
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• v.17 no.3
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• pp.32-38
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• 2012

This study was conducted to evaluate the slurping process affecting the variation of free product and VOCs concentration and the bioaugmentation effect on bioremediation process. Free products and soil gas were extracted from 30 extraction wells installed in a petroleum contaminated area. The extraction system was operated for 10 hours per day with 1 hour on-and-off mode. The thickness of free product in extraction well was decreased from 11.7 cm to 4.5 cm and the VOCs concentration was increased from 10.37 ppm to 30.78 ppm during the operation period. After the slurping process for 2 months, contaminated soil was treated with bioremediation process in 2 cells, $15{\times}40$ m, biologically enhanced with adjusting oxygen, moisture and nutrients concentration. Total 1,400 L of microbial inoculant, Naturesys. (Dong Myung Ent. Co.) was added to the pile B, which has an outstanding ability for degrading petroleum hydrocarbons. The results showed that bioremediaton effect in soil with the microorganisms solution is 33% higher than that in soil with only residual bacteria.

• Journal of Microbiology and Biotechnology
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• v.18 no.1
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• pp.63-66
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• 2008

Anthracene is a PAH that is not readily degraded, plus its degradation mechanism is still not clear. Thus, two strains of anthracene-degrading bacteria were isolated from long-term petroleum-polluted soil and identified as Sphingomonas sp. 12A and Pseudomonas sp. 12B by a 16S rRNA sequence analysis. To further enhance the anthracene-degrading ability of the two strains, the biosurfactants produced by Pseudomonas aeruginosa $W_3$ were used, which were characterized as rhamnolipids. It was found that these rhamnolipids dramatically increased the solubility of anthracene, and a reverse-phase HPLC assay showed that the anthracene degradation percentage after 18 days with Pseudomonas sp. 12B was significantly enhanced from 34% to 52%. Interestingly, their effect on the degradation by Sphingomonas sp. 12A was much less, from 35% to 39%. Further study revealed that Sphingomonas sp. 12A also degraded the rhamnolipids, which may have hampered the effect of the rhamnolipids on the anthracene degradation.

• Journal of Soil and Groundwater Environment
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• v.19 no.5
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• pp.9-17
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• 2014

This paper reported the use of real-time polymerase chain reaction (PCR), denaturing gradient gel electrophoresis (DGGE), and the culture-based method in the intrinsic bioremediation study at a petroleum contaminated site. The study showed that phenol hydroxylase gene was detected in groundwater contaminated with benzene, toluene, ethylbenzene, xylene isomers (BTEX) and methyl tert-butyl ether (MTBE). This indicated that intrinsic bioremediation occurred at the site. DGGE analyses revealed that the petroleum-hydrocarbon plume caused the variation in microbial communities. MTBE degraders including Pseudomonas sp. NKNU01, Bacillus sp. NKNU01, Klebsiella sp. NKNU01, Enterobacter sp. NKNU01, and Enterobacter sp. NKNU02 were isolated from the contaminated groundwater using the cultured-based method. Among these five strains, Enterobacter sp. NKNU02 is the most effective stain at degrading MTBE without the addition of pentane. The MTBE biodegradation experiment indicated that the isolated bacteria were affected by propane. Biodegradation of MTBE was decreased but not totally inhibited in the mixtures of BTEX. Enterobacter sp. NKNU02 degraded about 60% of MTBE in the bioreactor study. Tert-butyl alcohol (TBA), acetic acid, 2-propanol, and propenoic acid were detected using gas chromatography/mass spectrometry during MTBE degraded by the rest cells of Enterobacter sp. NKNU02. The effectiveness of bioremediation of MTBE was assessed for potential field-scale application.

• Journal of Microbiology and Biotechnology
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• v.1 no.1
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• pp.1-5
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• 1991

Sulfate-reducing bacteria have been isolated from soil and their abilities to degrade dibenzothiophene (DBT) were compared with those of type cultures. Among the strains tested a soil isolate M6 showed the highest ability to degrade DBT. Isolate M6 was characterized as a mesophilic obligatory anaerobe. The morphology of the bacterium was vibrioid with the size of $0.4-0.7{\;}\mu\textrm{m}{\;}by{\;}1.0-1.5{\;}\mu\textrm{m}$. Gram reaction was negative and nonsporulating. Desulfoviridin is present. Lactate, pyruvate, ethanol and malate supported growth of the bacterium in the presence of sulfate. Sulfate, sulfite, thiosulfate and sulfur served as electron acceptors for growth. Hydrogenase was present. The mol% of guanine and cytosine of DNA was determined as 56%. The bacterium produced viscous material. From these results, the isolate M6 was identified as Desulfovibrio desulfuricans.