• 미생물학회지
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• 제19권4호
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• pp.179-185
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• 1981

한강 수계에서 SDBS (Sodium Dodecyl Benzene Sulfonate)를 유일한 탄소원으로 가지는 최소배지에서 서란 120 균주중 $4^{\circ}C$에서 생장이 좋은 8균주를 선택하여 동정하였으며. 이들의 온도에 따른 생장파 분해능을 흡광도 분석기를 이용하여 측정하였다. 동정 결과. Ps. fluorescens가 4균주, Ps. putida가 2균주 이었다. 이들중 Ps. fluorescens LP6, Ps. lido Lei, Ps. fluorescens LS 6의 비생장율은 모두 $25^{\circ}C$에서 가장 높은 값을 나타냈으나 정체기에서의 균체량은 $5^{\circ}C$ 에서 가장 높았다. 따라서 이들 3 균주는 faculfative psychrophilic bacteria로 사료된다. 한편 SDBS의 분해는 세포가 정체기에 들어가면서 시작되었으며, 분해능은 $25^{\circ}C$C에서 가장 좋았다.

• Ocean and Polar Research
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• 제27권2호
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• pp.221-230
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• 2005

Recently there has been a rapid accumulation of knowledge of microbial life in cold and frozen ecosystems. This understanding has revealed the extensive diversity of psychrophilic prokaryotes. Cultivation-based and molecular-based surveys have been performed in Antarctic habitats ranging from glacial ice to continental shelf sediments. Results indicate that psychrophilic taxa permeate throughout the Bacteria while they represent a more mysterious element of diversity in the Archaea owing to a notable lack of cultured strains. In certain cold climate ecosystems the diversity of psychrophilic populations reach levels comparable to the richest temperate equivalents. Within these communities must exist tremendous genetic diversify that is potentially of fundamental and of practical value. So far this genetic pool has been hardly explored. Only recently have genomic data become available for various psychrophilic prokaryotes and more is required. This owes to the fact that psychrophilic microbes possess manifold mechanisms for cold adaptations, which not only Provide enhanced survival and Persistence but Probably also contributes to niche specialisation. These mechanisms, including cold-active and ice-active proteins, polyunsaturated lipids and exopolysaccharides also have a great interest to biotechnologists.

• 한국환경보건학회지
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• 제19권2호
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• pp.10-15
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• 1993

Hygienic condition of farm waters has an effect on the hygiene of dairy foods. So we examined Standard Plate Count, coliform, E. coli, heat-resistant bacteria, psychrophilic bacteria, Pseudomonas aeruginosa and enterococcus for the bacterial sanitation of 78 farm waters in Kyunggi Province. Of the 78 farm waters, the average number of psychrophilic bacteria was 750 $\pm$ 170/ml, SPC 440 $\pm$ 130/ml, Pseudomonas aeruginosa 130 $\pm$ 97/100/ml, Coliform 22 $\pm$ 17/ml, E. coli 10 $\pm$ 6/100/ml, Heatresistant bacteria 5 $\pm$ 1ml, and Enterococcus 2 $\pm$ 1/100/ml. The percent of over than 1000/ml in SPC and psychrophilic bacteria of 78 farm water was 11.5% and 23.1%, respectively. The rate of over than 10/ml in coliform and heat-resistant bacteria was 12.8% and 15.4%, respectively and the rate of over than 10/100 ml in E. coli, Pseudomonas aeruginosa and enterococcus was 8.9%, 33.3%, and 2.6%, respectively. Pseudomonas aeruginosa was no significant between any other indicator organisms, and psychrophilic bacteria was significant with only SPC but other indicator organisms were highly significant with each other.

• Bulletin of the Korean Chemical Society
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• 제30권11호
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• pp.2647-2650
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• 2009

Cold shock proteins (Csps) are a subgroup of the cold-induced proteins on reduction of the growth temperature below the physiological temperature. They preferentially bind to single-stranded nucleic acids to translational regulation via RNA chaperoning. Csp plays important role in cold adaptations for the psychrophilic microorganism. Recently, Cold shock protein from psychrophilic bacteria, Colwellia psychrerythraea (CpCsp) has been identified. Three dimensional structures of a number of Csps from various microorganisms have been solved by NMR spectroscopy or X-ray crystallography, but structures of psychrophilic Csps were not studied yet. Therefore, cloning and purification protocols for further structural study of psychrophilic Csp have been optimized in this study. CpCsp was expressed in E. coli with pET-11a vector system and purified by ion exchange, size exclusion, and reverse phase chromatography. Expression and purification of CpCsp in M9 minimal media was carried out and $^{15}N$-labeled proteins with high purity over 90% was obtained. Further study will be carried out to investigate the tertiary structure and dynamics of CpCsp.

• 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.

• Journal of the Korean Wood Science and Technology
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• 제51권4호
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• pp.270-282
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• 2023

Lower termites need symbiotic microbes for cellulose digestion. Elizabethkingia miricola strain BM10 has been proposed as a symbiotic microbe that assists in low-temperature digestion and metabolism of Reticulitermes speratus KMT1, a termite on Bukhan Mountain, Seoul, Korea. In E. miricola strain BM10, β-glucosidase genes expressed at 10℃ were identified, and the psychrophilic enzymatic characteristic was confirmed by heterogeneously expressed proteins. Crude β-glucosidase in the culture broth of E. miricola strain BM10 showed specific enzymatic properties, and its substrate affinity was 4.69 times higher than that of Cellic CTec2. Among the genes proposed as β-glucosidase, two genes, bglB_1 and bglA_2, whose gene expression was more than doubled at 10℃ than at 30℃, were identified. They were heterogeneously expressed in Escherichia coli and identified as psychrophilic enzymes with an optimal reaction temperature of about 20℃-25℃. In this study, E. miricola strain BM10, a symbiotic bacterium of lower termites, produced psychrophilic β-glucosidases that contribute to the spread of the low-temperature habitat of a lower termite, R. speratus KMT1.

• 한국버섯학회지
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• 제11권3호
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• pp.171-176
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• 2013

큰느타리버섯의 저온성적응성 형질에 관련된 SCAR marker를 개발하기 위하여 저온성 계통의 8균주와 대조구 8균주의 genomic DNA를 30 ug/ml의 농도로 bulking한 것을 주형 DNA로 사용하고 operon 사의 OPA(20개), OPB(20개), OPL(20개), OPP(20개), OPR(20개), OPS(20개) 등 총 120개 primer를 random primer(10 mer)로 사용하여 RAPD를 수행하였으며 이중에서 OP-S3 primer를 사용한 PCR 산물들이 대조구와 가장 뚜렷한 차이를 나타내었다. OP-S3 primer를 이용한 RAPD 결과, 약 480 bp 부근에서 저온성 계통에 특이적인 DNA band가 관찰되었으며 이 DNA band의 염기서열을 근거로 SCAR marker로 사용할 specific primer인 OP-S3-1-F와 OP-S3-1-R를 디자인하였다. SCAR marker OP-S3-1 primer를 이용하여 PCR을 수행한 결과에서는 저온성 계통에서만 480 bp 부근에서 대조구와 구별되는 DNA band를 확인할 수 있었으며 random primer인 OP-S3 primer를 이용하여 PCR을 수행했을 때보다 재현성이 높고 진한 DNA band를 확인할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2405-2409
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• 2011

The psychrophilic bacteria Psychromonas arctica survives at subzero temperatures by having adapted several protective mechanisms against freezing and oxidative stresses. Many reactive oxygen species are likely generated in P. arctica as a result of reduced metabolic turnover rates. A previous study identified the pasod gene for superoxide dismutase from P. arctica using a series of PCR amplifications. Here, upon cloning into a His-tag fused plasmid, the sod gene from P. arctica (pasod) was successfully expressed by IPTG induction. His-tagged PaSOD was subsequently purified by $Ni^{2+}$-NTA affinity chromatography. The purified PaSOD exhibited a higher SOD activity than that of Escherichia coli (EcSOD) at all temperatures. The difference in activity between PaSOD and EcSOD becomes even more significant at 4$^{\circ}C$, indicating that PaSOD plays a functional role in the cold adaptation of P. arctica in the Arctic.

• 미생물학회지
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• 제19권4호
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• pp.174-178
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• 1981

Psychrophilic yeast strains, HJ3011, HJ3023, and HJ3021, which were isolated from the Han River during winter season of December 1980 to February 1981 were identified as Candida sp., Candida nivalis, and Rhodotorula rubra respectively. The effect of temperature on growth was carried out in this study. Growth rate constants of strains HJ3011 and HJ3023 were the highest value at $15^{\circ}C\;and\;16{\sim}20^{\circ}C$ respectively, and both growth rates diminished gradually above $20^{\circ}C$ and were decreased to zero at $25^{\circ}C$. According to the results obtained in this experiment, above two strains of yeast were confirmed as psychrophile. On the other hand since the strain of HJ3021 exhibited the highest growth rate constant at $15^{\circ}C$ and could slightly grow above $25^{\circ}C$, this strain was defined as psychrotroph.

• Bulletin of the Korean Chemical Society
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• 제31권8호
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• pp.2410-2412
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• 2010