• KSBB Journal
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• v.14 no.3
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• pp.351-357
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• 1999

A marine bacterium Bacillus cereus ASK202, agarase producing strain, was treated with some mutagenic agents, ultraviolte(UV), 1-methyl-3-nitro-1-nitrosoguanidine(NTG), and ethyl methane sulfonate(EMS), several times for the increasing of the agarase production After mutagen treatment, we isolated one mutant strain treated with NTG showed the highest stability and agarase productivity and named as Bacillus cereus ASK202-N3. This Bacillus cereus ASK202-N3 strain was well grown in the modified marine medium containing 0.5%(w/v) agar, 0.3%(w/v) yeast extract, and 5.0%(w/v) NaCl, and the optimal initial pH, temperature and culture time were 7.8, $25^{\circ}C$ and 32h, respectively. In the optimal culture conditions, the agarase production was increased to 5.3 fold(850units/L) compared to that of the wild type.

• Journal of Microbiology
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• v.44 no.2
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• pp.200-205
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• 2006

The tributyltin (TBT)-resistant bacterium, Pseudomonas aeruginosa 25W, which was isolated in seawater from the Arabian Sea, was subjected to transcriptome analysis in the presence of high concentrations of TBT. Only slight effects were observed at TBT concentration of $50{\mu}M$, but exposure to $500{\mu}M$ resulted in the upregulation of 6 genes and the downregulation of 75. Among the 75 downregulated genes, 53% (40 out of 75) were of hypothetical function, followed by 14 transcriptional regulation- and translation-associated genes. The results of this study indicated that although the 25W strain was highly resistant to TBT, high concentrations of TBT result in toxic effect on the transcriptional and translational levels. The target genes likely belong to a specific category of transcription- and translation-associated genes rather than to other gene categories.

• Korean Journal of Microbiology
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• v.38 no.2
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• pp.81-85
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• 2002

A marine bacterium producing superoxide dismutase, strain number B446, was screened with nitrite quantitation method using hydroxy amine and photochemically generated superoxide ion, and the superoxide dismutase was purified through 35-75% ammonium sulfate precipitation, DEAE-Sephadex A-25 ion exchange chromatography, Sephadex G-200 gel filtration chromatography, and High-Q anion exchange chromatography to a yield of 6% and purification fold of 32.3.

• Journal of Microbiology
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• v.38 no.4
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• pp.224-229
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• 2000

Chitin-degrading marine bacterial strain 98CJ11027 was isolated from bryozoa from the coastal area of Cheju Island, Korea, and identified as a member of the genus Vibrio. The molecular mass of the main extracellular chitinase (chitinase I), purified from strain 98CJ11027, was estimated to be 98 kDa. The optimal condition for chitinase I activity is pH 6.0 and 45$^{\circ}C$. The activity was inhibited by Fe$\^$+2/ and Cu$\^$+2/. Chitinase I displayed the hydrolysis type of chitobiosidase and catalyzed reversed hydrolysis leading to the synthesis of tetraacetylchitotetraose.

• Journal of Life Science
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• v.18 no.1
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• pp.58-62
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• 2008

A novel agar-degrading bacterium SL-12 was isolated from seashore of Kijang at Busan, Korea, and cultured in marine broth 2216 media. Isolated bacterium SL-12 was identified as Glaciecola genus by 16S rDNA sequencing with 98% identity. The optimum pH of the enzyme activity was 7.0 and the optimum temperature for the reaction was $30^{\circ}C$. The enzyme hydrolyzed neoagarohexaose to yield neoagarobiose as the main product, indicating that the enzyme is ${\beta}$-agarase. Thus, isolated bacterium and the enzyme would be useful for the industrial production of neoagarobiose.

• Microbiology and Biotechnology Letters
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• v.16 no.5
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• pp.384-388
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• 1988

A marine bacterium Achromobacter sp. M-1220 was isolated from enrichment culture for emulsification of Bunker-C oil. The bacterium can emulsify approximately 7.5g of Bunker-C oil per liter in sen water medium within 1 drys at 18$^{\circ}C$ and multiply from 8$\times$10$^5$ cells to 9$\times$10$^9$ cells per mi. Optimum pH and salt concentration were pH 7.5 and 3% for the emulsification of Bunker-C oil. Emulsification takes place actively in both high sulfur-containing Bunker-C oil and high sulfur-con-taming crude oil. The amount of emulsification depends on the exogenous addition of nitrogen and phosphate sources. The bacterium can also utilize n-hexndecane, n-paraffin me benzene among the petroleum compounds as a sole carbon source.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.237-240
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• 2006

Seventy-one marine bacteria decomposing sea tangle (Laminaria japonica) into single cell detritus (SCD) were isolated from sea water, sea tangle, sea mustard (Undaria pinnatifida), sea urchin (Anthocidaris crassispina), star fish (Acanthaster planci), and turban cell (Batillus cornutus), among which 14 strains decreased cutting strength of sea tangle and had alginate-degrading activity. Marine bacterium No. 34 isolated from turban cell showed lowest cutting strength of sea tangle, strongest alginate-degrading activity, and produced high content of $5-10\;{\mu}m$ SCD from sea tangle. This strain was identified as Vibrio sp. based on morphological, physiological, and biochemical characteristics and named as Vibrio sp. YKW-34.

• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.204.2-204
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• 2005

• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.182.1-182
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• 2005

• 한국생물공학회:학술대회논문집
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• 2005.10a
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• pp.220-221
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• 2005