• Microbiology and Biotechnology Letters
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• v.35 no.2
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• pp.150-157
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• 2007

The advanced bioremediation of diesel-contaminated soil through the exploration of bacterial interaction with plants was studied. A diesel-degrading rhizobacterium, Rhodococcus sp.412, and a plant species, Zea mays, having tolerant against diesel was selected. Zea mays was seeded in uncontaminated soil or diesel-contaminated soil with or without Rhodococcus sp. 412. After cultivating for 30 days, the growth of Zea mays in the contaminated soil inoculated with Rhodococcus sp. 412 was better than that in the contaminated soil without the bacterium. The residual diesel concentrations were lowered by seeding Zea mays or inoculating Rhodococctis sp. 412. These results Indicate that the simultaneous use of Zea mays and Rhodococcus sp. 412 can give beneficial effect to the remediation of oil-contaminated soil. Bacterial community was characterized using a 16S rDNA PCR and denaturing gradient gel electrophoresis (DGGE) fingerprinting method. The similarities of DGGE fingerprints were $20.8{\sim}39.9%$ between the uncontaminated soil and diesel contaminated soil. The similarities of DGGE fingerprints were $21.9%{\sim}53.6%$ between the uncontaminated soil samples, and $31.6%{\sim}50.0%$ between the diesel-contaminated soil samples. This results indicated that the structure of bacterial community was significantly influence by diesel contamination.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.6
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• pp.550-553
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• 2000

Optimum temperature for paralytic shellfish poison (PSP) detoxofication of Enterobacter sp. CW-6 isolated from sea water and changes of contents and ingredients composition of PSP during bacterial detoxification process were investigated. Enterobacter sp. CW-6 detoxicated $61.5{\~}67.7{\%}\;and\;87.4{\~}96.8{\%}$ of initial PSP toxicity ($25.0{\~}28.5\;nmole/g$) after $5{\~}12$ days at 30 and $35^{\circ}C$, identified as optimal growth temperature, respectively. The detoxification rate of Enterobacter sp. CW-6 for crude PSP with initial concentration of 38.2 nmole/g after 8 and 12 days at $30^{\circ}C$ in the Marine broth was 88.4 and $92.7{\%}$, respectively. During bacterial detoxification process using crude toxin solution, temporary increasement of STX group was detected and identified that was derived from GTX2, 3 group. The detoxification rate of Enterobaoter sp. CW-6 on purified GTX1 and 4 with initial concentration 47 nmole/g and 37 nmole/g were more than $90{\%}$ after 12 days in the marine broth at $30^{\circ}C$. Enterobacter sp. CW-6 also showed a detoxification activity on purified GTX2 and 3, and the detoxification rate for the initial concentration 25.6 nmole/g after 12 days was $66.4{\%}$.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2002.05b
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• pp.452-454
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• 2002

A biosurfactant-producing microorganism, .Pseudomouos sp. EL-G527 was isolated from activated sludge by enrichment culture when grown on mineral salt medium containing n-hexadecane as a carbon source. The biosurfactant from .Pseudomonar sp. EL-G527 exhibited lesser toxicity to bacterial population than synthetic surfactants and in the biodegradation test, biosurfactant was rapidly degraded and lost its activity as surface active material after 1 day incubation. In this study, the biosurfactant from Pseudomonas sp. EL-G527 was effective surface-active compound, more biodegradable and less toxic to microbial ecosystem than various synthetic surfactants.

• Plant Disease and Agriculture
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• v.5 no.1
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• pp.41-45
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• 1999

Bacterial population densities on soybean pods from Chungnam province ranges 105~106 CFU/$\textrm{cm}^2$, whereas those of bacteria causing sprout rot ranged 0~103 CFU/$\textrm{cm}^2$. Erwinia chrysanthemi, Xanthomonas campestris pv. glycines, Staphylococcus sp., and Micrococcus sp. were identified as pathogenic bacteria causing soybean sprout rot. The population density of X. campestris pv. glycines was higher than those of other bacteria.

• Journal of Environmental Science International
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• v.10 no.3
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• pp.239-245
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• 2001

This research was performed to investigate the dynamics of microbial community by RBC (Rotating Biological Contactor) using Rhodococcus sp. EL-GT and activated sludge. Cell counts revealed by DAPI were compared with culturable bacterial counts from nutrient agar. Colony counts on nutrient agar gave values 20~25% and 1~15% of cell counts (DAPI). The cell counts for the dynamics of bacterial community were determined by combination of in situ hybridization with fluorescently-labelled oligonyucleotide probes and epifluorescence microscopy. Around 90~80% of total cells visualized DAPI were also detected by the bacteria probe EUB 338. For both reactors proteobacteria belonging to the gamma subclass were dominant in the first stage (1 and 2 stage) and proteobacteria belonging to the gamma subclass were dominant in the last stage (3 and 4 stage).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.3
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• pp.207-215
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• 2011

An endosulfan degrading bacterial strain, K-1321, was isolated by endosulfan-enrichment culture from a seaside sediment collected at Dadaepo Beach, Busan, Korea. The strain was identified as a Serratia sp. based on the results of morphological, biochemical and 16S rDNA homology analyses. Serratia sp. K-1321 was able to completely degrade 50 ppm endosulfan in culture media and soil within 6 weeks at $25^{\circ}C$. GC/MS analysis revealed that endosulfan diol was an intermediate of the bacterial endosulfan degradation. Considering the above results, we concluded that Serratia sp. K-1321 utilized endosulfan as a carbon source and metabolized endosulfan via a less toxic pathway, such as the formation of endosulfan diol as an intermediate.

• Journal of the Korean Society of Tobacco Science
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• v.24 no.1
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• pp.7-12
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• 2002

During the screening or antiviral substances having inhibitory effect on tobacco mosaic virus(TMV) infection to tobacco plants, we found that a bacterial isolate, KTB61, which was identified as a Pseudomonas sp., strongly inhibited the formation of TMV local lesions. When the culture filtrate from KTB61 was applied on the upper surface of leaves of N. tabaccum Xanthi-nc tobacco at the same time of or 24 hours before TMV inoculation, almost complete inhibition was achieved. Incidence of systemic TMV infection to the susceptible tobacco cultivar, NC82, was reduced by 95% when TMV was inoculated onto the upper surface of leaves 24 hours after spraying the culture filtrate. Also 75∼80% of inhibitory effect was obtained by the inoculation of TMV onto the under surface of the leaves treated with culture filtrate 24 hours beforehand. In field trials, the TMV infection was reduced by 96.5% when the tobacco seedlings, N. tabaccum cv. NC82, were soaked with culture filtrate before transplanting.

• Microbiology and Biotechnology Letters
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• v.2 no.2
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• pp.103-109
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• 1974

In the cource of the studies on L-glutamic acid production from acetic acid, 383 strains capable of assimilating acetate as sole source of carbon were isolated from 279 kinds of soil sample. Out of them, 5 strains which produced relatively larger amount of L-glutamate from acetate were selected and named Brevibacterium flavum nov. sp. D1005B, Corynebacterium glutamicum nov. sp. D1025A, Brevib. flavum nov. sp. D2209B, Coryneb. acetoacidophilum nov. sp. D2212B and Coryneb. acetoacidophilum nov. sp. D2349A respectively.

• Korean Journal of Microbiology
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• v.40 no.4
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• pp.320-327
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• 2004

Three hundreds thirty two bacterial colonies which were able to degrade crude oil were isolated from soil sam­ples that were contaminated with oil in Daejeon area. Among them, one bacterial strain was selected for this study based on its higher oil degrading ability, and this selected bacterial strain was identified as Acinetobactor sp. B2 through physiological-biochemical tests and analysis of its 16S rRNA sequence. Acinetobactor sp. B2 was able to utilize various carbohydrates but did not utilize trehalose and mannitol as a sole carbon source. Acinetobactor sp. B2 showed a weak resistance to antibiotics such as kanamycin, streptomycin, tetracycline and spectinomycin, but showed a high resistance up to mg/ml unit to heavy metals such as Ba, Li, Mn, AI, Cr and Pb. The optimal growth temperature of Acinetobactor sp. B2 was $30^{\circ}C.$ The lipase produced by Acinetobactor sp. B2 was purified by ammonium sulfate precipitation, DEAE-Toyopearl 650M ion exchange chromatography and Sephadex gel filtration chromatography. Its molecular mass was about 60 kDa and condition for the optimal activity was observed at $40^{\circ}C$ and pH 10, respectively. The activation energy of lipase for the hydrolysis of p­nitrophenyl palmitate was 2.7 kcal/mol in the temperature range of 4 to $37^{\circ}C,$ and the enzyme was unstable at the temperature higher than $60^{\circ}C.$ The Michaelis constant $(K_m)\;and\;V_{max}$ for p-nitrophenyl palmitate were 21.8 uM and $270.3\;{\mu}M\;min^{-1}mg^{-1},$ respectively. This enzyme was strongly inhibited by 10 mM $Cd^{2+},\;Co^{2+},\;Fe^{2+},\;Hg^{2+},$ EDTA and 2-Mercaptoethalol.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.404-410
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• 2009

We investigated the physicochemical stabilities and biological activities of ethanol- extracted pigment from marine bacteria Pseudoalteromonas sp. Ju11-1 and Pseudoalteromonas sp. Ju14. The bacterial pigment of strain Ju11-1 was very stable at pH 5.0 below $25^{\circ}C$. The stability of the pigment showed higher stability in the presence of metal ions such as $Cu^{2+}$ and $Mg^{2+}$. The pigment has activity of free-radical scavenging ($IC_{50}$ $95.2{\mu}g$/ml) and the protective antioxidant effect ($ED_{50}$ $82.3{\mu}g$/ml) against DNA damage in human lymphocytes. The bacterial pigment of strain Ju14 was very stable at pH range between 4.0 and 8.0 below $40^{\circ}C$. In the presence of light, the pigment was also very stable, showing more than 90 percent of remaining absorbance during 14 days at $25^{\circ}C$. The stability of the pigment, when metal ions were present, showed higher stability in all examined metal ions except for $Fe^{2+}$, $Al^{3+}$, and $Cu^{2+}$, especially in the presence of $Na^+$. The pigment has activity of freeradical scavenging ($IC_{50}$ $208.6{\mu}g$/ml) and the protective antioxidant effect ($ED_{50}$ $ 96.4{\mu}g$/m) against DNA damage in human lymphocytes. The result indicates that the bacterial pigments from marine bacteria, Pseudoalteromonas sp. Ju11-1 and Pseudoalteromonas sp. Ju14 showed higher physicochemical stability and significant effects for reduction in oxidative DNA damage. Therefore, the results suggest that these bacterial pigments could be used as a natural colorant having the advantages of antioxidant.