• Molecules and Cells
• /
• 제25권2호
• /
• pp.258-264
• /
• 2008

Deschampsia antarctica is the only monocot that thrives in the tough conditions of the Antarctic region. It is an invaluable resource for the identification of genes associated with tolerance to various environmental pressures. In order to identify genes that are differentially regulated between greenhouse-grown and Antarctic field-grown plants, we initiated a detailed gene expression analysis. Antarctic plants were collected and greenhouse plants served as controls. Two different cDNA libraries were constructed with these plants. A total of 2,112 cDNA clones was sequenced and grouped into 1,199 unigene clusters consisting of 243 consensus and 956 singleton sequences. Using similarity searches against several public databases, we constructed a functional classification of the ESTs into categories such as genes related to responses to stimuli, as well as photosynthesis and metabolism. Real-time PCR analysis of various stress responsive genes revealed different patterns of regulation in the different environments, suggesting that these genes are involved in responses to specific environmental factors.

• 미생물학회지
• /
• 제48권4호
• /
• pp.293-297
• /
• 2012

극지의 다양한 환경으로부터 분리되어 극지연구소 PAMC(Polar and Alpine Microbial Collection)에 보관중인 169개 균주들을 0.4% colloidal chitin이 첨가된 ZoBell 고체배지에서 배양하여 chitinase 활성을 균주 27개를 선별하였다. 그 중 PAMC 21693 균주는 저온에서 pNP-$(GlcNAc)_1$를 기질로 사용했을 때 가장 큰 활성을 보였고, $4-37^{\circ}C$의 온도 범위 중 $4^{\circ}C$에서 가장 높은 개체수 증가율을 보였다. PAMC 21693의 chitinase 유전자를 클로닝한 결과 2,619 bp의 ORF를 포함하는 총 2,857 bp의 염기서열을 확보하였다. 대장균에서 chitinase 유전자의 재조합 단백질을 발현한 결과 분자량 96 kDa의 재조합 단백질을 확인할 수 있었다. 본 논문에서는 극지 미생물 유래 저온활성 chitinase들의 생물공학 분야에서의 이용가능성을 제시하였다.

• 한국지구물리탐사학회:학술대회논문집
• /
• 한국지구물리탐사학회 2005년도 공동학술대회 논문집
• /
• pp.139-144
• /
• 2005

남극 웨델해 북부에 위치한 남스코시아해령을 가로지르는 측선에 대하여 다중채널 탄성파 탐사를 수행하였다. 남스코시아해령은 남극반도의 연장선에 존재하는 대륙지각으로 각각 해양지각인 스코시아해와 포웰분지와 접하고 있다. 남스코시아해령은 스코시아 판의 남쪽 가장자리를 이루고 있는 동-서 방향의 좌선 변환단층을 따라 횡장력에 의해 만들어졌다. 남스코시아해령 중앙에 위치한 중앙 함몰대는 경사부정합이 존재하며 남스코시아해령의 확장과정에 나타난 구조로 해석된다.

• 지구물리
• /
• 제8권4호
• /
• pp.215-219
• /
• 2005

남극 웨델해 북부에 위치한 남스코시아해령을 가로지르는 측선에 대하여 다중채널 탄성파 탐사를 수행하였다. 남스코시아해령은 남극반도의 연장선에 존재하는 대륙지각으로 각각 해양지각인 스코시아해와 포웰분지와 접하고 있다. 남스코시아해령은 스코시아 판의 남쪽 가장자리를 이루고 있는 동-서 방향의 좌선 변환단층을 따라 횡장력에 의해 만들어졌다. 남스코시아해령 중앙에 위치한 중앙 함몰대는 경사부정합이 존재하며 남스코시아해령의 확장과정에 나타난 구조로 해석된다.

• 한국지구물리탐사학회:학술대회논문집
• /
• 한국지구물리탐사학회 2011년도 학술대회 및 정기총회
• /
• pp.145-146
• /
• 2011

• 환경분석과 독성보건
• /
• 제21권4호
• /
• pp.229-236
• /
• 2018

In this study, inter-laboratory comparison was done using elemental analyzer-isotope ratio mass spectrometers (EA-IRMSs) to determine carbon and nitrogen contents as well as stable carbon and nitrogen isotopic compositions (${\delta}^{13}C$ and ${\delta}^{15}N$) of five environmental samples containing lake and marine sediments, higher plant leaves, and fish muscle, and one organic analytical standard (Protein (Casein) Standard OAS). Five national laboratories participated in this comparison study, and each laboratory analyzed all five samples and the analytical standard. Results showed that variations in total organic carbon (TOC) and total nitrogen (TN) contents as well as ${\delta}^{13}C_{TOC}$ and ${\delta}^{15}N_{TN}$ values among the laboratories were large compared to the analytical uncertainties. The results highlighted the inhomogeneity of the test samples and thus, the need to select suitable standard reference materials for future inter-laboratory studies. Further inter-laboratory comparison exercises could promote good measurement practices in the acquisition of stable carbon and nitrogen isotopic composition data.

• 생명과학회지
• /
• 제30권11호
• /
• pp.931-938
• /
• 2020

TCTP는 다양한 진핵생물에서 풍부하게 존재하는 단백질 중에 하나이며, 암, 세포 증식, 유전자 조절 등과 관련된 세포의 생리학적 기작에서 중요한 역할을 담당하는 것으로 알려져 왔다. 더구나, TCTP는 dithiothreitol (DTT)나 hydrogen peroxide (H₂O₂)에 의해 유도되는 산화적 스트레스에 대한 저항성에 관여하는 중요한 단백질로 주목 받아 왔다. 한편, 극지역 서식 생물들은 강한 자외선에 의해 발생한 활성산소를 조절하기 위한 다양한 항산화 방어체계를 가지고 있다. 본 연구에서는 북극 동물플랑크톤 Calanus glacialis에서 분리된 TCTP가 산화적 스트레스 하에서 E. coli 세포의 저항성에 미치는 효과를 관찰하였다. C. glacialis에서 분리된 TCTP 유전자(ORF 522 bp) 서열을 분석하였고, 약 23 kDa의 재조합 단백질을 제작하였다. 관찰 결과, TCTP 재조합 단백질이 E. coli 세포에서 과발현 되었을 때, 세포들은 H₂O₂에 의해 유도된 산화적 스트레스에 대한 저항성이 증가하는 것을 확인하였다. 본 관찰을 통해, 북극 C. glacialis TCTP 단백질의 항산화 조절자로서의 역할에 대한 가능성을 처음으로 제시하였다.

• Journal of Microbiology
• /
• 제44권5호
• /
• pp.480-491
• /
• 2006

As part of the long-term monitoring projects on Antarctic terrestrial vegetation in relation to global climate change, a lichen floristical survey was conducted around the Korean Antarctic Station (King Sejong Station), which is located on Barton Peninsula, King George Island, in January and February of 2006. Two hundred and twenty-five lichen specimens were collected and sixty-two lichen species in 38 genera were identified by morphological characteristics, chemical constituents, TLC analysis and ITS nucleotide sequence analysis.

• Journal of Microbiology
• /
• 제45권6호
• /
• pp.510-514
• /
• 2007

Twenty-five bacterial strains that secrete mucous materials were isolated from sediment obtained from King George Island, Antarctica. Seven of these strains proved capable of producing cryoprotective exopolysaccharides. The strain KOPRI 21653 was selected for the further study of an anti-ice-nucleating polysaccharide (ANP), which originated from a polar region. KOPRI 21653 was identified as Pseudoalteromonas arctica as the result of 16S rRNA analysis. The exopolysaccharide, P-21653, was purified completely from the KOPRI 21653 cell culture via column chromatography and protease treatment. The principal sugar components of P-21653 were determined to be galactose and glucose, at a ratio of 1:1.5, via GC-MS analysis. The cryoprotective activity of P-21653 was characterized via an E. coli viability test. In the presence of 0.1% (w/v) P-21653, the survival ratio of E. coli cells was as high as 82.6% over three repeated freeze-thaw cycles. The survival ratio decreased drastically to 71.5 and 48.1 %, respectively, in five and seven repeated cycle conditions; however, the survival ratios were greater over three (96.6-92.1%) to seven (100.5-91.6%) freeze-thaw cycles in the presence of 0.5 and 1.0% (w/v) P-21653. In addition, at much lower concentrations (0.1-1.0%), P-21653 resulted in survival ratios (83.1-98.4%) similar to those of two commercially available cryoprotectants ($V_{EG}$ plus X-1000, 92.9% and $V_{M3}$, 95.3%), which were utilized at the recommended concentrations (90%). The biochemical characteristics of exopolysaccharide P-21653 reflect that this compound may be developed as a useful cryoprotectant for use in medical applications and in the food industry.

• Bulletin of the Korean Chemical Society
• /
• 제32권6호
• /
• pp.1925-1930
• /
• 2011

Psychrophilic bacteria have acquired cold-resistance in order to protect themselves against freezing temperatures, which would otherwise be lethal. DnaK/DnaJ/GrpE systems are molecular chaperones which facilitate proper folding of newly synthesized proteins. Efficient folding processes are of great importance especially in a cold environment, such as the Arctic. In order to understand the protection mechanisms of psychrophilic bacteria against cold temperatures, we have explored a genome of KOPRI22215, tentatively identified as Psychromonas arctica, whose genome sequence has not yet been discovered. With an aim of searching for a coding gene of DnaK from KOPRI22215, we have applied a series of polymerase chain reactions (PCR) with homologous primers designed from other Psychromonas species and LA PCR in vitro cloning. 1917 bp complete coding sequence of dnaK from KOPRI22215 was identified including upstream promoter sites. Recombinant plasmids to overexpress PaDnaK along with EcDnaK (DnaK of E. coli) were then constructed in pAED4 vector and the pET-based system to induce PaDnaK expression by IPTG. Characterization assays of expressed PaDnaK were carried out by measuring survival rates upon 4 day incubation at 4 $^{\circ}C$: a refolding assay as molecular chaperone, and ATPase assay for functional activity. Taking account of all the data together, we conclude that PaDnaK was identified, successfully expressed, and found to be more efficient in providing cold-resistance for bacterial cells.