• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.103-106
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• 2003

This study was conducted to evaluate in-situ bioremediation ability of Bioil-D, microbial material for oil degradation, at a gas station that had been treated by SVE system. TPH concentrations and total contaminated soil volume were rapidly decreased after Bioil-D treatment. The performance of Bioil-D was also estimated based on the observation of microbial population at the soil samples and $CO_2$ concentration produced at the extraction wells. The field study showed a successful work of Bioil-D.

• Journal of Life Science
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• v.21 no.11
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• pp.1511-1517
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• 2011

We isolated a potent phenanthrene-degrading bacterium from oil-contaminated soils of Suzhou, China, and assessed the potential use of these bacteria for bioremediation of soils contaminated by polycyclic aromatic hydrocarbons (PAHs) in a microcosm. Based on 16S rDNA sequencing, we identified this bacteria as Sphigobacterium sp. SW-09. By PCR amplification, we also identified catechol 2,3-dioxygenase genes (nahH genes) mediating PAH degradation. Staphylococcus sp. KW-07, which has been identified in our previous study, showed potential for use in bioremediation of oil-contaminated soils. In this experiment, we compared the rate of phenanthrene-degradation between Staphylococcus sp. KW-07 and Sphingobacterium sp. SW-09 in a microcosm condition. Newly isolated Sphingobacterium sp. SW-09 showed a higher phenanthrene-degradation rate than that of Staphylococcus sp. KW-07 in soil microcosms. Together, our results suggest that the Sphingobacterim sp. SW-09 strain isolated from the Suzhou area may also be useful in bioremediation of PAH-contaminated soils.

• Journal of Microbiology and Biotechnology
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• v.16 no.5
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• pp.704-715
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• 2006

Oil spill was found in 1999 from a diesel storage facility located near the top of Baekun Mountain in Uiwang City. Application of bioremediation techniques was very relevant in removing oil spills in this site, because the geological condition was not amenable for other onsite remediation techniques. For efficient bioremediation, bacterial communities of the contaminated site and the uncontaminated control site were compared using both molecular and cultivation techniques. Soil bacterial populations were observed to be stimulated to grow in the soils contaminated with diesel hydrocarbon, whereas fungal and actinomycetes populations were decreased by diesel contamination. Most of the dieseldegrading bacteria isolated from contaminated forest soils were strains of Pseudomonas, Ralstonia, and Rhodococcus species. Denaturing gradient gel electrophoresis (DGGE) analysis revealed that the profiles were different among the three contaminated sites, whereas those of the control sites were identical to each other. Analysis of 16S rDNA sequences of dominant isolates and clones showed that the bacterial community was less diverse in the oil-contaminated site than at the control site. Sequence analysis of the alkane hydroxylase genes cloned from soil microbial DNAs indicated that their diversity and distribution were different between the contaminated site and the control site. The results indicated that diesel contamination exerted a strong selection on the indigenous microbial community in the contaminated site, leading to predominance of well-adapted microorganisms in concurrence with decrease of microbial diversity.

• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.607-613
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• 2001

The biodegradation rates of diesel oil by a selected diesel-degrading bacterium, Pseudomonas stutzeri strain Y2G1, and microbial consortia composed of combinations of 5 selected diesel-degrading bacterial were determined in liquid and soil systems. The diesel degradation rate by strain Y2G1 linearly increased $(R^2=0.98)$ as the diesel concentration increased up to 12%, and a degradation rate as high as 5.64 g/l/day was obtained. The diesel degradation by strain Y2G1 was significantly affected by several environmental factors, and the optimal conditions for pH, temperature, and moisture content were at pH8, $25^{\circ}C$, and 10%, respectively. In the batch soil microcosm tests, inoculation, especially in the form of a consortium, and the addition of nutrients both significantly enhanced the diesel degradation by a factor of 1.5 and 4, respectively. Aeration of the soil columns effectively accelerated the diesel degradation, and the initial degradation rate was obviously stimulated with the addition of inorganic nutrients. Based on these results, it was concluded that the major rate-limiting factors in the tested diesel-contaminated soil were the presence of inorganic nutrients, oxygen, and diesel-degrading microorganisms. To resolve these limiting parameters, bioremediation strategies were specifically designed for the tested soil, and the successful mitigation of the limiting parameters resulted in an enhancement of the bioremediation efficiency by a factor of 11.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.199-202
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• 2002

Many methods have been developed for the remediation of contaminated soil and groundwater. Among those technologies, in-situ bioremediation is most likely to be cost-effective method for petroleum hydrocarbon contamination. But the in-situ bioremediation can require more time to remediate hydrocarbon-contaminated soil and groundwater than other methods. Therefore we intended to save time of in-situ bioremediation using a biological additive to activate indigenous microbes in soil. The additive, 'Inipol EAP 22' stimulates the growth of specific flora, significantly accelerating the speed at which hydrocarbons are biodegraded. And it hans been tested in accordance with protocol approved by the USEPA and is registered on the National Contingency Plan Product Schedule List. In the experiment, three soil samples contaminated with fuel oil were prepared in the same concentration. Inipol EAP 22 was not added to one sample and was added to the other two samples with 5% and 10% of hydrocarbon by weight respectively. And $CO_2$gas derived from bacterial respiration was analyzed in each samples for 15 days. As a result, 145% and 153% of $CO_2$ evolution (microbial respiration) against the sample without 'Inipol EAP 22' occurred in samples with 'Inipol EAP 22' addition of 5% and 10%, respectively

• Microbiology and Biotechnology Letters
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• v.32 no.1
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• pp.91-95
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• 2004

For the detection of the oil-degrading bacterium, Nocardia sp. Hl7-1, inoculated during the bioremediation of oil-contaminated soil, a species-specific primer was constructed based on the 16S rDNA sequence of this strain. Two forward primers and two reverse primers were designed and tested against both closely and distantly related bacterial strains. All the primers designed were specific to the Nocardia sp. H17-1. Particularly, primer sets NH169F-NH972R and NH575F-NH972R could be used to detect 50 fg of template DNA and TEX>$1.2${\times}$10^4$ CFU/g of sandy soil. These two PCR primer sets successfully detected the H 17-1 strain in the oil-con-laminated soil samples containing heterogeneous DNA. We also conformed the primer specificity by restriction-enzyme cleavage of the PCR products and denaturing gradient gel electrophoresis.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.166.2-166
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• 1998

No Abstract, See Full Text

• Journal of Microbiology and Biotechnology
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• v.17 no.1
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• pp.67-73
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• 2007

The present study compared the microbial diversity and activity during the application of various bioremediation processes to crude oil-contaminated soil. Five different treatments, including natural attenuation (NA), biostimulation (BS), biosurfactant addition (BE), bioaugmentation (BA), and a combined treatment (CT) of biostimulation, biosurfactant addition, and bioaugmentation, were used to analyze the degradation rate and microbial communities. After 120 days, the level of remaining hydrocarbons after all the treatments was similar, however, the highest rate (k) of total petroleum hydrocarbon (TPH) degradation was observed with the CT treatment (P<0.05). The total bacterial counts increased during the first 2 weeks with all the treatments, and then remained stable. The bacterial communities and alkane monooxygenase gene fragment, alkB, were compared by denaturing gradient gel electrophoresis (DGGE). The DGGE analyses of the BA and CT treatments, which included Nocardia sp. H17-1, revealed a simple dominant population structure, compared with the other treatments. The Shannon-Weaver diversity index (H') and Simpson dominance index (D), calculated from the DGGE profiles using 16S rDNA, showed considerable qualitative differences in the community structure before and after the bioremediation treatment as well as between treatment conditions.

• KSBB Journal
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• v.24 no.1
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• pp.53-58
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• 2009

This study was focused on the investigation of the characteristics of TPH and BTEX removal in oil-contaminated sandy soil and fine soil with injection of microorganisms, nutrients, and surfactants. As the result of the experiments maintained moisture contents by 10${\sim}$20%, the TPH removal efficiency in oil-contaminated sandy soil was the highest in C-1 (microorganisms+nutrients), and the efficiency in C-2 (microorganisms+nutrients+surfactants) was higher than the efficiency in C-0(microorganisms). In 81 days, TPH removal efficiency in case of C-0, C-1 and C-2 showed 51%, 83%, 63% respectively. The results of D group with fine soil showed similar trends as C group, but the TPH removal efficiency of D group was lower than that of C group. Those of both C and D group were the highest in 1 group (microganisms+nutrients). The pH of fine soil was some lower than that of sandy soil or was similar to sandy soil. In 14 days, BTEX removal efficiency in case of C-0, C-1, C-2, D-0, D-1 and D-2 showed 99.8%, 99.4%, 96.0%, 99.5%, 99.2%, 96.3% respectively. Those of both C and D group were the highest in 0 group (microganisms).

• Korean Journal of Microbiology
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• v.39 no.2
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• pp.102-107
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• 2003

With the enrichment culture technique, bacterial strains which degrade diesel oil were isolated from soil contaminated with diesel oil. One of the isolates named GENECO 1 showed the highest activity for emulsification of diesel oil as well as the highest growth rate. This strain, GENECO 1, was identified as a Pseudomonas sp. based on its biochemical, physiological characteristics and 16S rDNA sequences. The optimal cultural conditions for cell growth and oil emulsifying activity of its culture were as follow; $30^{\circ}C$ for temperature, 7.0 for pH. Diesel oil degradation was analysed by the gas chromatography. More than 95% of 1% treated diesel oil were converted into a form no longer extractable by mixed organic solvents after 96 hours incubation.