• Journal of Microbiology
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• 제45권4호
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• pp.281-285
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• 2007

Cold environments, including polar and alpine regions, are colonized by a wide diversity of micro-organisms able to thrive at low temperatures. There is evidence of a wide range of metabolic activities in alpine cold ecosystems. Like polar microorganisms, alpine microorganisms playa key ecological role in their natural habitats for nutrient cycling, litter degradation, and many other processes. A number of studies have demonstrated the capacity of alpine microorganisms to degrade efficiently a wide range of hydrocarbons, including phenol, phenol-related compounds and petroleum hydrocarbons, and the feasibility of low-temperature bioremediation of European alpine soils by stimulating the degradation capacity of indigenous microorganisms has also been shown.

• 미생물학회지
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• 제48권4호
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• pp.293-297
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• 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.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2007년도 International Meeting of the Microbiological Society of Korea
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• pp.86-88
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• 2007

• Journal of Microbiology and Biotechnology
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• 제22권7호
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• pp.902-906
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• 2012

Expressed sequence tags (ESTs) from the Antarctic green algae Pyramimonas gelidicola were analyzed to obtain molecular information on cold acclimation of psychrophilic microorganisms. A total of 2,112 EST clones were sequenced, generating 222 contigs and 219 singletons, and 200 contigs and 391 singletons from control ($4^{\circ}C$) and cold-shock conditions ($-2^{\circ}C$), respectively. The complete EST sequences were deposited to the DDBJ EST database (http://www.ddbj.nig.ac.jp/index-e.html) and the nucleotide sequences reported in this study are available in the DDBJ/EMBL/GenBank. These EST databases of Antarctic green algae can be used in a wide range of studies on psychrophilic genes expressed by polar microorganisms.

• 한국미생물·생명공학회지
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• 제42권3호
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• pp.293-296
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• 2014

본 논문에서는 극지미생물의 저온 활성 protease 생산에 관한 연구를 수행하였다. 먼저 protease를 생산하는 극지미생물인 PAMC 25641, 25614, 25719, 25617을 16s rDNA 염기서열 분석을 이용하여 동정하였다. 그 후, 다양한 온도($5^{\circ}C$, $10^{\circ}C$, $15^{\circ}C$, $20^{\circ}C$)에서의 성장률 및 protease activity, specific activity를 확인하였다. 각 미생물의 온도별 성장률은 대체로 비슷한 경향을 보였으나 25617은 $20^{\circ}C$에서 급격한 성장률 증가를 확인할 수 있었다. 또한, specific activity는 25641이 5, 15, $20^{\circ}C$에서 가장 높은 specific activity를 갖는 것을 확인하였다.

• ALGAE
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• 제21권2호
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• pp.169-174
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• 2006

We have cultured more than 100 Arctic and Antarctic cryophilic microalgal strains in KOPRI culture collections of polar microorganisms (KCCPM). Among them, we tried to identify an Antarctic strain, KOPRI AnM0008 by morphological and molecular analysis. Nuclear SSU rDNA and plastid rbcL sequences were used to identify the strain. It was identified as Porosira pseudodenticulata based on SSU sequence data showing 99% identity with GenBank X85398. This result was supported by morphological features like solitary labiate process, external foramina and internal cribra by optical and scanning electron microscope. Morphological identification and molecular analysis on polar cryophilic microalgae will be accomplished to construct the databases for KCCPM.

• 치위생과학회지
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• 제24권2호
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• pp.84-96
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• 2024

Background: Recent studies have elucidated the quorum-sensing mechanisms, biofilm formation, inter-pathogen interactions, and genes related to oral pathogens. This review aims to explore the recent expansion of drug targets against oral pathogens and summarize the current research on novel antibiotic substances derived from marine organisms that target oral pathogens. Methods: A comprehensive literature review summarized the novel mechanisms pertaining to quorum-sensing signal transmission systems, biofilm formation, and metabolite exchange in oral pathogens. The amino acid sequences of the 16 proteins identified as potential drug targets were systematically classified and compared across various oral microorganisms. Results: Through a literature review, we identified nine studies researching quorum sensing signaling inhibitors targeting oral pathogens. A comparison of the amino acid sequences of 16 potential drug targets in oral microorganisms revealed significant differences between oral pathogens and beneficial oral symbiotic microorganisms. These findings imply that it is possible to design drugs that can bind more selectively to oral pathogens. Conclusion: By summarizing the results of recent research on the signaling mechanisms that cause pathogenicity, new drug targets against oral pathogens were proposed. Additionally, the current status of developing new antibiotics for oral pathogens using recently developed quorum sensing inhibitors and natural products derived from marine organisms was introduced. Consequently, marine natural products can be used to develop drugs targeting new proteins in oral pathogens.

• Ocean and Polar Research
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• 제29권3호
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• pp.263-271
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• 2007

The survival strategies of polar organisms at permanently or extremely cold temperatures and their application to cryobiology were reviewed here. In addition, ongoing studies on psychrophiles also were described. Psychrophiles are extremophiles that can grow and reproduce in cold temperatures, typically at -10 to $20^{\circ}C$. These organisms developed various mechanisms of adaptation to extremely cold environments. Polar organisms cope with these extreme physicochemical conditions using strategies such as avoidance, protection and partnership with other organisms. Understanding on the strategies adopted by polar organisms may provide insight on the physiological process that cells can go through during freezing. Cryopreservation may be able to take advantage of the findings described above. Currently, genomes of many cold-loving organisms have been sequenced and comparative genomics has revealed, at a molecular level, the characteristics of these organisms. The investigation of microorganisms on the polar glaciers may expand our understanding on the origin of life on Earth and other planets.

• 한국미생물·생명공학회지
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• 제40권4호
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• pp.380-388
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• 2012

북극 지의류로부터 서로 다른 5종의 극지 미생물을 분리하였고, 그들의 생리활성 물질들은 아세톤, 물, 클로로포름, 다이에틸에테르, 에탄올, 에틸아세테이트, 메탄올 및 페트롤륨 에테르 등 다양한 용매를 이용하여 균 배양액으로부터 추출되었다. 이러한 추출물들의 항균성은 Staphylcoccus aureus, Bacillus subtilis, Micrococcus luteus, Enterobacter cloacae, Pseudomonas aeruginosa 및 Escherichia coli 등 6종의 병원체에 대한 디스크 확산법과 최소억제농도 측정법에 의해 조사되었다. 여러 추출 샘플 중, Burkholderia sordidicola S5-$B^T$ (KOPRI 26644) 유사미생물 종의 에틸아세테이트 추출물이 표적박테리아에 대한 높은 항균활성을 나타내었다(억제대, 7-10 mm; 최소억제농도, $57.5{\rightarrow}1000{\mu}g/ml$). 또한, 다양한 추출 용매 중, 클로로포름 추출물에서 약하지만 분명한 활성을 나타내었다.

• ALGAE
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• 제37권2호
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• pp.175-183
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• 2022

Polar microorganisms produce physiologically active substances to adapt to harsh environments, and these substances can be used as biomedical compounds. The green microalga Micractinium variabile KSF0031, which was isolated from Antarctica, produced phytol, a natural antimicrobial agent. Furthermore, several polyunsaturated fatty acids (PUFAs), including omega-3, exhibit antioxidant properties. Here statistical methods (Plackett-Burman design and Box-Behnken design) were used to optimize the culture medium of KSF0031 to improve biomass production, and K₂HPO₄, MgSO₄·7H ₂O, and ammonium ferric citrate green (AFCg) were selected as significant components of the culture medium. Changes in the concentration of K₂HPO₄ and MgSO₄·7H ₂O as positive factors and AFCg as a negative factor affected cell growth to a remarkable degree. The biomass production in a 100 L culture using the optimized medium for 24 d at 18℃ was improved by 37.5% compared to that obtained using the original BG-11 medium. The quantities of PUFAs and phytol obtained were 13 mg g^-1 dry cell weight (DCW) and 10.98 mg g^-1 DCW, which represent improved yields of 11.70% and 48.78%, respectively. The results of this study could contribute to an improved production of phytol and fatty acids from Antarctic microalgae in the biomedical industry.