• Journal of Microbiology
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• 제42권2호
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• pp.156-159
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• 2004

In general, the salinity of the ocean is close to 3.5％ and marine vibrios possess the respiratory chain-linked Na$\^$+/ pump. The influence of sodium chloride and the proton conductor carbonylcyanide m-chlo-rophenylhydrazone (CCCP) on the production of extracellular proteases in a marine Vibrio strain was examined. At the concentration of 0.5 M, sodium chloride minimally inhibited the activity of extra-cellular proteases by approximately 16％, whereas at the same concentration, the producton of extra-cellular proteases was severely inhibited. On the other hand, the production of extracellular proteases was completely inhibited by the addition of 2 ${\mu}$M CCCP at pH 8.5, where the respiratory chain-linked Na$\^$+/ pump functions.

• 생명과학회지
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• 제29권11호
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• pp.1173-1178
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• 2019

본 연구에서는 agarose를 분해하는 세균을 분리하고 한천분해효소의 특성을 조사하였다. 한천분해세균인 BK-1은 부산광역시 수영구 광안리해수욕장에서 채취한 바닷물-시료에서 Marine agar 2216 평판배지를 이용하여 분리하였다. 분리된 균은 16S rRNA 유전자 염기서열분석을 통해 Agarivorans sp. BK-1으로 명명하였다. 세포 외 agarase는 Agarivorans sp. BK-1 균주 배양액에서 획득하였으며, 이를 이용하여 효소의 특성을 조사하였다. Agarivorans sp. BK-1 균주의 한천분해효소는 20, 30, 40, 50, 60 및 $70^{\circ}C$에서 각각 67, 93, 97, 100, 58, 52%의 상대활성을 나타냈으며, pH 5, 6, 7, 8에서는 59, 100, 95, 91%의 활성을 나타내었다. 세포 외 agarase는 $50^{\circ}C$에서 pH 6.0인 20 mM Tris-HCl 완충용액을 사용하였을 때 최대의 활성을 보였다. 이 agarase는 20, 30, $40^{\circ}C$에서 2시간 동안 열처리하여도 90% 이상의 잔존활성을 보였다. 또한, $50^{\circ}C$에서 2시간 동안 노출된 후에도 56%의 잔존활성을 보였다. 60과 $70^{\circ}C$에서 30분 동안 노출된 후에는 효소활성 대부분이 사라졌다. Zymogram 분석을 통하여 Agarivorans sp. BK-1 균주가 약 110, 90, 55 kDa 크기의 한천분해효소들을 생산하는 것을 확인할 수 있었다. TLC 분석 결과, Agarivorans sp. BK-1 균주의 한천분해효소는 네오한천올리고당인 neoagarobiose (46.8%), neoagarotetraose (39.7%) 및 neoagarohexaose (13.5%)를 생성하는 것으로 보아 ${\beta}$-agarase로 확인되었다. 따라서 Agarivorans sp. BK-1가 생산하는 ${\beta}$-agarase는 보습효과, 세균성장 억제, 미백효과, 식품, 화장품 및 전분노화 방지 등의 기능을 가지는 네오한천올리고당의 생산에 유용할 것으로 판단된다.

• 생명과학회지
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• 제25권11호
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• pp.1273-1279
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• 2015

경상남도 남해군 연안의 해수를 이용하여 신규의 한천분해 해양성세균을 분리하고 한천분해효소의 특징을 분석하였다. Marine agar 2216 배지에서 분리한 SH-1 균주는 16S rRNA 유전자 염기서열분석을 통해 Simiduia 속 세균과 99% 유사하여 Simiduia sp. SH-1으로 명명하였다. Simiduia sp. SH-1 균주가 생성하는 한천분해효소는 성장의존성 산물로 판단되었으며 정체기부터 효소활성이 감소되었다. 한천분해효소는 pH 7.0(20 mM Tris-HCl buffer), 30℃에서 최대활성(698.6 units/l)을 나타내었다. 효소의 활성은 30℃에서 최적이었고 이후 온도가 증가함에 따라 활성이 감소하였으며, 40℃와 50℃에서 각각 약 90%와 75%의 상대활성을 보였으나 내열성은 보이지 않았다. 최적 pH인 pH 7.0에 비해 pH 6.0에서는 오차범위 내에서 조금 낮은 활성을 보였으며 pH 5.0과 pH 8.0에서는 각각 80%와 75% 정도의 상대활성을 보였다. TLC 분석을 통하여 Simiduia sp. SH-1 균주가 생성하는 한천분해효소는 agarose를 분해하여 피부의 미백활성, 전분노화의 방지 및 세균성장의 억제 등의 유용한 효과를 가지는 기능성 한천올리고당인 neoagarotetraose와 neoagarobiose를 최종적으로 생성하는 β-agarase로 확인되었다. 따라서, Simiduia sp. SH-1 균주와 이 균주가 생산하는 β-agarase는 산업적 생산에 유용하게 활용될 수 있을 것으로 기대된다.

• Journal of Microbiology
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• 제38권3호
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• pp.150-155
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• 2000

A bioluminescent assay method for detecting the activity of phospholipase C(PLC; phosphatidyl choline cholinephosphohydrolase, EC 3.1.4.3) was developed using bioluminescent marine bacteria. Phospholipase C from Bacillus cereus and sn-1,2- dimyristoyl glycerol was further hydrolyzed with lipase from Candida ecylidracea. The hydrolyzed myristic acid was quantified using a dark mutant of Vibrio harveyi (designated as M-17). The in vivo light intensity of which was stimulated specifically up to one thousand fold in the presence of myristic acid. The rates of the hdrolysis of the DMPC substrate by the phospholipase measured by the luminescence method were linear with time and the were estalished to detect as little as 0.1 mUnit of phospholipase C and 5 nM of myristic acid production.

• 한국수산과학회지
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• 제45권1호
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• pp.30-34
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• 2012

The filamentous bacterium Leucothrix mucor, an epiphyte of seaweed, showed antifouling activity against Ulva pertusa spore settlement and germling development. The chemical constituents representing the antifouling activity were identified as giffinisterone B and oleamide based on nuclear magnetic resonance (NMR) spectroscopy and mass spectroscopy (MS). Approximately 3.6 mg of giffinisterone B and 2.8 mg of oleamide were isolated from 1.6 g of Leucothrix mucor crude extract. Giffinisterone B fully inhibited spore settlement and germling development at $100{\mu}g/mL$. Oleamide inhibited spore settlement at $10{\mu}g/mL$ and germling development at $100{\mu}g/mL$.

• Journal of Microbiology
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• 제40권3호
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• pp.234-236
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• 2002

A blue pigment-producing bacterium, Vogesella indigofera, was isolated and quantified for the relationship between its synthesis of a blue pigment and exposure concentrations of $Cr^{6+}$. The concentration of $Cr^{6+}$ and the percentage of blue colonies on agar plates was negatively correlated ($r^{2}$ =-0.8683). Critical concentrations inhibiting bacterial pigment production were found to be between 100-150 $\mu\textrm{g}$ $Cr^{6+}$/ml on agar plates and 200-300 $\mu\textrm{g}$ $Cr^{6+}$/ml in liquid culture. As the blue color is characteristic and easily observable, the bacterium Vogesella indigofera may have potential applications in the detection and monitoring of environmental pollution.

• Fisheries and Aquatic Sciences
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• 제18권1호
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• pp.35-44
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• 2015

We previously identified Streptomyces griseus as an anti-cancer agent (Kim et al., 2014). In this study, we isolated compounds from S. griseus and evaluated their anticancer effect and toxicity in vitro and in vivo. Preparative centrifugal partition chromatography (CPC) was used to obtain three compounds, cyclo($_{\small{L}}$-[4-hydroxyprolinyl]-$_{\small{L}}$-leucine], cyclo($_{\small{L}}$-Phe-trans-4-hydroxy-$_{\small{L}}$-Pro) and phenethyl acetate (PA). We chose PA, which had the highest anticancer activity, as a target compound for further experiments. PA induced the formation of apoptotic bodies, DNA fragmentation, DNA accumulation in $G_0/G_1$ phase, and reactive oxygen species (ROS) formation. Furthermore, PA treatment increased Bax/Bcl-xL expression, activated caspase-3, and cleaved poly-ADP-ribose polymerase (PARP) in HL-60 cells. Simultaneous evaluation in vitro and in vivo, revealed that PA exhibited no toxicity in Vero cells and zebrafish embryos. We revealed, for the first time, that PA generates ROS, and that this ROS accumulation induced the Bcl signaling pathway.

• Journal of Microbiology
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• 제45권6호
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• pp.505-509
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• 2007

An obligately aerobic bacterium, strain KOPRI $20902^T$, was isolated from a marine sediment in Ny-${\AA}$lesund, Spitsbergen Islands, Norway. Cells were irregular rods and motile with polar monotrichous flagellum. The optimum growth temperature was $17-22^{\circ}C$. Cells grew best in pH 7.0-10.0 and 3-4% sea salts (corresponding to 2.3-3.1% NaCl). The novel strain required $Ca^{2+}$ or $Mg^{2+}$ in addition to NaCl for growth. Sequence analysis of 16S rRNA gene revealed that the Arctic isolate is distantly related with established species (<92.4% sequence similarity) and formed a monophyletic group with Cellvibrio, which formed a distinct phylogenetic lineage in the order Pseudomonadales. Predominant cellular fatty acids [$C_{16:1}\;{\omega}7c/15:0$ iso 2OH (45.3%), $C_{16:0}$ (18.4%), ECL 11.799 (11.2%), $C_{10:0}$ 3OH (10.4%)]; DNA G+C content (37.0 mol%); nitrate reduction to nitrogen; absence of aesculin hydrolysis, N-acetyl-${\beta}$-glucosaminidase and esterase; no assimilation of arabinose, galactose, glucose, lactose, maltose, and trehalose differentiated the strain from the genus Cellvibrio. Based on the phylogenetic and phenotypic characteristics, Dasania marina gen. nov., sp. nov. is proposed in the order Pseudomonadales. Strain KOPRI $20902^T$ (=KCTC $12566^T$=JCM $13441^T$) is the type strain of Dasania marina.

• Journal of Microbiology and Biotechnology
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• 제15권5호
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• pp.1080-1086
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• 2005

Membranes prepared from Vibrio natriegens oxidized both NADH and deamino-NADH as substrates. The maximum activity of the membrane-bound NADH oxidase was obtained at about pH 8.5 in the presence of 0.2 M NaCl, whereas that of the NADH:ubiquinone oxidoreductase was obtained at about pH 7.5 in the presence of 0.2 M NaCl. Electron transfer from NADH or deamino-NADH to ubiquinone-l or oxygen generated a considerable membrane potential (${\Delta}{\psi}$), which occurred even in the presence of $20{\mu}M$ carbonylcyanide m-chlorophenylhydrazone (CCCP). However, the ${\Delta}{\psi}$ was completely collapsed by the combined addition of $10{\mu}M$ CCCP and $20{\mu}M$ monensin. On the other hand, the activity of the NADH oxidase and the ${\Delta}{\psi}$ generated by the NADH oxidase system were inhibited by about $90\%$ with $10{\mu}M$ HQNO, whereas the activity of the NADH:ubiquinone oxidoreductase and the ${\Delta}{\psi}$ generated at the NADH:ubiquinone oxidoreductase segment were inhibited by about $60\%$. Interestingly, the activity of the NADH:ubiquinone oxidoreductase and the ${\Delta}{\psi}$ generated at the NADH:ubiquinone oxidoreductase segment were resistant to the respiratory chain inhibitors such as rotenone, capsaicin, and $AgNO_3$, and the activity of the NADH oxidase and the ${\Delta}{\psi}$ generated by the NADH oxidase system were very sensitive only to $AgNO_3$. It was concluded, therefore, that V. natriegens cells possess a $AgNO_3$-resistant respiratory $Na^+$ pump that is different from the $AgNO_3$-sensitive respiratory $Na^+$ pump of a marine bacterium, Vibrio alginolyticus.

• Journal of Microbiology and Biotechnology
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• 제6권6호
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• pp.391-396
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• 1996

The Gram-negative marine bacterium Marinomonas vaga, which requires 0.5 M NaCl concentration for optimal growth, is slightly halophilic. The growth of M vaga was highly resistant to the proton conductor, carbonyl cyanide m-chlorophenylhydrazone (CCCP) under alkaline pH conditions (pH 8.5) but very sensitive to CCCP under acidic pH conditions (pH 6.5). These results suggest that the respiratory chain-linked NADH oxidase system of M. vaga may lead to generation of a $Na^{+}$ electrochemical gradient. In order to examine the existence of $Na^{+}$-stimulated NADH oxidase in M. vaga, membrane fractions were prepared by the osmotic lysis method. The membrane-bound NADH oxidase oxidized both NADH and deamino-NADH as substrates and required $Na^{+}$ for maximum activity. The maximum activity of NADH oxidase was obtained at about pH 8.5 in the presence of 0.2 M NaCl. The site of $Na^{+}$-dependent activation in the NADH oxidase system was at the NADH:quinone oxidoreductase segment. The NADH oxidase and NADH:quinone oxidoreductase were very sensitive to the respiratory chain inhibitor, 2-heptyl-4-hydroxyquinoline-N-oxide (HQNO) in the presence of 0.2 M NaCl but highly resistant to another respiratory inhibitor, rotenone. Based on these findings, we conclude that M. vaga possesses the $Na^{+}$-dependent NADH:quinone oxidoreductase that may function as an electrogenic $Na^{+}$ pump.