• Korean Journal of Microbiology
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• v.53 no.4
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• pp.265-272
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• 2017

Some bacteria with different mechanisms for hydrocarbon degradation were isolated from oil-contaminated soils in Korea. Isolate Acinetobacter calcoaceticus SL1 showed biosurfactant- producing activity in oil-spreading test, and it exhibited a good emulsifying activity of 43.6 and 54.5% for diesel oil and n-hexane, respectively. It also has high cell surface hydrophobicity which can make it easily attaches to hydrocarbons and degrade them. It degraded 100% of 1,000 mg/L of n-octadecane and naphthalene, respectively in 3 days, 72.3% of 1,000 mg/L diesel oil in 7 days and 78.0% of 10,000 mg/L diesel oil in oil-contaminated soil during 28 days. Isolated strains Bacillus amyloliquefaciens S10 and B. subtilis GO9 can produce biosurfactant and formed 6.34 and 2.5 cm diameter of clear zones, respectively in oil-spreading test. Surface tension of their culture supernatant reduced from 74.6 to 34.4 and 33.3 mN/m, respectively during incubation, and critical micelle concentrations of culture supernatants were 2.0 and 5.9%, respectively. Consortium of A. calcoaceticus SL1 and B. amyloliquefaciens S10 degraded 77.8% of 10,000 mg/L diesel oil in 3 days, which indicated more efficient oil degradation than that by A. calcoaceticus SL1 alone. If these bacteria were applied together as a consortium to oil-contaminated sites, they may show a high removal rate of petroleum hydrocarbons.

• Journal of Microbiology and Biotechnology
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• v.10 no.3
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• pp.333-337
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• 2000

An oil-degrading yeast, Yarrowia lipolytica 180, exhibits interesting cell surface characteristics under the growth on hydrocarbons. An electron microscopic study revealed that the cells grown on crude oil showed protrusions on the cell surface, and thicker periplasmic space and cell wall than the cell surface, and thicker periplasmic space and cell wall than the cells grown on glucose. Y. lipolytica cells lost its cell hydrophobicity after pronase(0.1 mg/ml) treatment. The strain produced two types of emulsifying materials during the growth on hydrocarbons; one was water-soluble extracellular materials and the other was cell wall-associated materials. Both emulsifying materials at lower concentration (0.12%) enhanced the oil-degrading activity of Moraxella sp. K12-7, which had medium emulsifying activity and negative cell hydrophobicity; however, it inhibited the oil-degrading activity of Pseudomunas sp. K12-5, which had medium emulsifying activity and cell hydrophobicity. These results suggest that the oil-degrading activity of Y. lipolytica 180 is closely associated with cell surface structure, and that a finely controlled application of Y.lipolytica 180 in combination with other oil-degrading microorganisms showed a possible enhancing efficiency of oil degradation.

• Korean Journal of Microbiology
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• v.34 no.3
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• pp.101-107
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• 1998

Biological treatment of Arabian light crude oil-contaminated pebble was investigated in laboratory microcosms after supplementation with inorganic nutrients and oil-degrading microorganisms. Glass columns ($10cm{\times}20cm$) were used as microcosms and each microcosm was filled with pebbles of diameter less than 40 mm. After initial oil contamination of 2.4% (w/v), Inipol EAP-22 or slow release fertilizer (SRF) was added as inorganic nutrients and microorganisms were sprayed over pebbles. When $C_{17}$/pristane and $C_{18}$/phytane ratios were used as a marker for oil biodegradation, both ratios for microcosm supplemented with SRF and microorganisms were the lowest (below detectable range) after 92 days. Elimination of oil by abiotic processes, however, were minimal with decrease of $C_{17}$/pristane and $C_{18}$/phytane ratios from 3.55 and 2.41 to 3.06 and 1.50, respectively. The numbers of heterotrophic and oil-degrading microorganisms, and biological activity (dehydrogenase activity) corresponded to the course of biodegradation activities in all microcosms. During the whole experimental period, there was no significant nutrient deficiency only in the microcosm with SRF and microorganisms. It seemed that a continuous supply of inorganic nutrients using SRF was the most important factor for the successful performance of biological treatment in oil-contaminated pebbles.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.26 no.6
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• pp.519-528
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• 1993

The biodegradation experiment, the TOD analysis and the element analysis for dispersant, Bunker-C and dispersant/Bunker-C oil mixtures were conducted for the purposes of evaluating the biodegradability of dispersnat/Bunker-C oil mixtures and studying the consumption of dissolved oxygen with relation to biodegradation in the seawater. The results of biodegradation experiment showed the mixtures with $1:10{\sim}5:10$ mix ratios of dispersant to 4mg/l of Bunker-C oil to be $0.34{\sim}2.06mg/l$ of $BOD_5$ and to be $1.05{\sim}5.47mg/l$ of $BOD_{20}$ in natural seawater. The results of TOD analysis showed 1mg of Bunker-C oil to be 3.16mg of TOD. The results of element analysis showed the contents of carbon and hydrogen to be $87.3\%\;and\;11.5\%$ for Bunker-C oil, respectively, but nitrogen element was not detected in Bunker-C oil. The biodegradability of dispersant/Bunker-C oil mixture shown as the ratio of $BOD_5$/TOD was increased from $3\%\;to\;11\%$ as a mix ratio of dispersant to 4mg/l of Bunker-C oil changed from 1:10 to 5:10, and the mixtures were found to belong in the organic matter group of low-biodegradability. The deoxygenation rates($K_1$) and ultimate oxygen demands($L_o$) obtained through the biodegration experiment and Thomas slope method were found to be $0.072{\sim}0.097/day$ and $1.113{\sim}6.746mg/l$ for the mixtures with $1:10{\sim}5:10$ mix ratios of dispersant to 4mg/l of Bunker-C oil, respectively. The ultimate oxygen demand of mixture was increased as a mix ratio of dispersant to Bunker-C oil changed from 1:10 to 10:5. This means that the more dispersants are applied to the sea for Bunker-C oil cleanup, the more decreases the dissolved oxygen level in the seawater.

• Journal of Microbiology and Biotechnology
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• v.16 no.4
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• pp.605-612
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• 2006

A psychrotrophic bacterium was isolated from oil-contaminated groundwater and identified as Rhodococcus sp. YHLT-2. Growth was observed at the temperature of 4 to $30^{\circ}C$. This strain degraded various petroleum hydrocarbons such as crude oil, diesel oil, and gasoline over the whole range of temperatures tested. The Rhodococcus sp. YHLT-2 was capable of growing even at $4^{\circ}C$, exhibiting 90% of oil biodegradation after 20 days. Degradation of crude oil occurred at low temperature in nature. This strain was also able to grow at 7% NaCl, and utilized not only short chain alkenes $(C_9\;to\;C_{12})$, but also a broad range of long chain alkenes $(C_{19}\;to\;C_{32})$ present in crude oil at $4^{\circ}C$. The Rhodococcus sp. YHLT-2 is expected to be of potential use in the in situ bioremediation of hazardous hydrocarbons under low-temperature and high-salt conditions.

• Journal of Korean Society on Water Environment
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• v.20 no.5
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• pp.447-451
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• 2004

The various pretreatment processes were evaluated to remove organic pollutants of weathered oil contaminated seawater(WOCS) for reverse osmosis desalination process, Biodegradation, coagulation, ultrafiltration, advanced oxidation processes and granular activated carbon filtration were used to evaluate the potential of organic pollutants removal in WOCS. Dissolved Organic Carbon(DOC) was almost not removed by biodegradation in WOCS. DOC was removed by 25% and 10% with the addition of $FeCl_3$ and PAC in WOCS, respectively. The removal efficiency using ultrafiltration(WOCS 500) was about 20% of DOC and 40% of $E_{260}$, respectively. In AOP application of WOCS, the removal of organic materials was improved up to 60% by the combination of $UV/O_3$ compared to UV process. However, 98% of DOC in woes could be removed by granular activated carbon filtration. It is revealed that activated carbon filtration is the best process for the pretratment of DOC removal.

• Journal of Microbiology
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• v.37 no.4
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• pp.185-192
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• 1999

A phenanthrene-degrading bacterium was isolated from an oil-spilled intertidal sediment sample and identified as Sphingomonas sp. KH3-2. The strain degraded polycyclic aromatic compounds such naphthalene, fluorene, biphenyl, and dibenzothiophene. When strain KH3-2 was cultured for 28 days at 25C, a total of 500 ppm of phenanthrene was degrated with a concomitant production of biomass and Folin-Ciocalteau reactive aromatic intermediates. Analysis of intermediates during phenanthrene degradation using high-performance liquid chromatography and gas chromatography/mass spectrometry indicated that Sphingomonas sp. KH3-2 primarily degrades phenanthrene to 1-hydroxy-2-naphthoic acid (1H2NA) and further metabolizes 1H2NA through the degradation pathway of naphthalene.

• KSBB Journal
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• v.14 no.2
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• pp.192-197
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• 1999

marine bacterium Pseudomonas sp. CHCS-2 produced the biosurfactant in the culture broth which contained 2%(w/v) arabian light crude oil and the productivity of biosurfactant was increased with the addition of glucose. The crude oil in the culture broth was degraded by this strain and carbon chain of $_nC_{12}~_nC_{22}$ was completely degradaded during the incubation for 196 h. The crude biosurfactant was purified by Amberlite XAD-7, Sepharose CL-4B and DEAE-Sepharose CL-6B column chromatography. Therefore, 0.21g/L of the purified biosurfactnat was obtained. The purified biosurfactant was a type of lipoprotein and the molecular weight was estimated as 67kDa by SDS-PAGE. The lipid composition was identified as octadecanoic acid by gas chromatography/mass spectrometry. And then, the N-terminal amino acid sequence of the protein was determined as Ser-Val-lle-Asn-Thr-lle-X-Met-lle-Gly-Gln-Gln- and the sequence did not show homology to any other known lipoprotein. Therefore, the purified lopoprotein was predicted novel biosurfactant.

• Journal of Soil and Groundwater Environment
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• v.11 no.1
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• pp.1-6
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• 2006

The analysis of functional population and its dynamics on the environment is essential for understanding bioremediation in environment. Here, we report a method for oligonucleotide microarray for the monitoring of aliphatic and aromatic degradative genes. This microarray contained 15 unique and group-specific probes which were based on 100 known genes involved pathways in biodegradation. Hybridization specificity tests with pure cultures, strain Pseudomonas aeruginosa KCTC 1636 indicated that the designed probes on the arrays appeared to be specific to their corresponding target genes. It was found that the presence of 8 genes encoding alkane, naphthalene, biphenyl, pyrene (PAH ring-hydroxylating) degradation pathway could be detected in oil contaminated soil sample. Therefore, the findings of this study strongly suggest that oligonucleotide microarray is an effective diagnostic tool for evaluating biodegradation capability in oil contaminated subsurface environment.

• Journal of the Korea Organic Resources Recycling Association
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• v.7 no.1
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• pp.67-77
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• 1999

The biodegradation of algae coagulated with poly aluminum chloride(PAC) was investigated by using the thermophilic oxic process. The compositions of coagulated algae were 83.5% of water content, 24.6% of ash, 32% of organic carbon with in total solid, respectively. In present study, food waste oil was used for the increment of calorie of mixtures in order to accelate the microbial activity. As a result, the maximum temperature of mixtures was higher than $50^{\circ}C$ when the mixing ratio of food oil was over 10%. However the temperature indicated the lower than $50^{\circ}C$ when conditions of no mixing with waste food oil, and 5% of mixing ratio. Therefore, the optimum condition was 10% of the mixing ration at $217l{\cdot}m^{-3}{\cdot}min^{-1}$ of air supply rate. The conversion efficiency of carbon was highest as 92% at the optimum condition. And then water was evaluated from imxture without accumulation at 10% of mixing ratio. The thermophilic oxic process well conducted that is good process for the treatment of waste algae without effluents however it has to consider the retreatment of accumulated aluminum in the reactor.