• BMB Reports
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• 제37권3호
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• pp.282-291
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• 2004

Phytases catalyze the release of phosphate from phytic acid. Phytase-producing microorganisms were selected by culturing the soil extracts on agar plates containing phytic acid. Two hundred colonies that exhibited potential phytase activity were selected for further study. The colony showing the highest phytase activity was identified as Aspergillus niger and designated strain 113. The phytase gene from A. niger 113 (phyI1) was isolated, cloned, and characterized. The nucleotide and deduced amino acid sequence identity between phyI1 and phyA from NRRL3135 were 90% and 98%, respectively. The identity between phyI1 and phyA from SK-57 was 89% and 96%. A synthetic phytase gene, phyI1s, was synthesized by successive PCR and transformed into the yeast expression vector carrying a signal peptide that was designed and synthesized using P. pastoris biased codon. For the phytase expression and secretion, the construct was integrated into the genome of P. pastoris by homologous recombination. Over-expressing strains were selected and fermented. It was discovered that ~4.2 g phytase could be purified from one liter of culture fluid. The activity of the resulting phytase was 9.5 U/mg. Due to the heavy glycosylation, the expressed phytase varied in size (120, 95, 85, and 64 kDa), but could be deglycosylated to a homogeneous 64 kDa species. An enzymatic kinetics analysis showed that the phytase had two pH optima (pH 2.0 and pH 5.0) and an optimum temperature of $60^{\circ}C$.

• 한국수의병리학회지
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• 제1권1호
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• pp.61-65
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• 1997

Epizootic streptococal infction is one of the common disease in guinea pig. We have confirmed 54 case of epizootic streptococal infection in guinea pig by histopathology and epidemiology. Grossly infection is characterized by the presense one to several enlarged lymph nodes particularly of the mandible cervical lymph nodes and accompanied by pleuropneumonia. Histologically there were lymphadenitis with abscesses surrounded by loose connective tissue fibrinopurulent pneumonia pleuritis myocarditis pericarditis and peritonitis. Epidemiological survey revealed that mortality was high in young adult female(15.1%) and changeable weather season such as spring and fall. From findings it was suggested that epizootic streptococal infection of guinea pig begin to infect in breeding colony around weaning period and died from that infection at animal facility during the quarantine period.

• Animal cells and systems
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• 제1권4호
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• pp.565-569
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• 1997

Vocal repertoires of the B1ack-tailed gull (Larus crassirostris) were studied at established reproductive colonies. The Black-tailed gull has eleven different vocal signals which can be grouped into three different call classes according to behavioral functions: contact call, alarm call (attention call), and aggressive call. The contact call or mew call is the most frequently used and functions as means of recognition among individuals, particularly between parents and youngs. Our results show that each call plays .an important role in particular social relationships in a high- density breeding colony.

• 한국육종학회지
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• 제43권5호
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• pp.448-456
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• 2011

적색 과육 '홍양' 품종에서 차등발현하는 유전자를 찾기 위하여 mirror orientation selection (MOS)과 결합된 suppression subtractive hybridization (SSH) 실험을 수행하였다. 그 결과, 288개의 cDNA clone을 확보하였으며, colony PCR을 통해 192개의 positive clone을 선발하였고, 이들을 sequencing하였다. NCBI/Genbank 데이터베이스의 BLAST 검색를 이용하여 염기서열을 분석한 결과, 30개의 clone에서 기존에 알려진 유전자기능과의 유사성을 확인할 수 있었으며, 10개의 clone이 특이유전자였다. 그 중 3개의 clone(AcF21, AcF42, AcF106)은 과실 후숙과 관련된 ACC-oxidase와 상동성이 있었다. SSH의 결과를 통해 얻어진 이 유전자들의 차등발현양상을 확인하기 위하여 reverse transcription PCR(RT-PCR)과 quantitative real-time PCR(qReal-time PCR) 분석을 실시하였다. qReal-time PCR분석과 RT-PCR분석에서 모두 동일한 결과를 확인할 수 있었으며, 3개 clone 모두 '홍양'에서의 유전자발현수준이 '헤이워드'보다 더 높았다. AcF21은 다른 유전자들보다 가장 높은 발현수준을 나타내었는데, 만개 후 120일과 160일 모두 '홍양'에서의 발현수준이 높았다.

• Journal of Microbiology and Biotechnology
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• 제13권6호
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• pp.881-891
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• 2003

Paenibacillus polymyxa is a plant growth-promoting rhizobacterium (PGPR) which can be used for biological control of plant diseases. Several bacterial strains were isolated from rotten roots of Korean ginseng (Panax ginseng C. A. Meyer) that were in storage. These strains were identified as P. polymyxa, based on a RAPD analysis using a P. polymyxa-specific primer, cultural and physiological characteristics, an analysis utilizing the Biolog system, gas chromatography of fatty acid methyl esters (GC-FAME), and the 16S rDNA sequence analysis. These strains were found to cause the rot in stored ginseng roots. Twenty-six P. polymyxa strains, including twenty GBR strains, were phylogenetically classified into two groups according to the ERIC and BOX-PCR analyses and 16S rDNA sequencing, and the resulting groupings systematized to the degrees of virulence of each strain in causing root rot. In particular, highly virulent GBR strains clustered together, and this group may be considered as subspecies or biovar. The virulence of the strains seemed to be related to their starch hydrolysis enzyme activity, but not their cellulase or hemicellulase activity, since strains with reduced or no starch-hydrolytic activity showed little or no virulence. Artificial inoculation of the highly virulent strain GBR-1 onto the root surfaces of Korean ginseng resulted in small brown lesions which were sunken and confined to the outer portion of the root. Ginseng root discs inoculated in vitro or two-year-old roots grown in soil drenched with the inoculum developed significant rot only when the inoculum density was $10^{6}-10^{7}$ or more colony-forming units (CFU) per ml. These results suggest that P. polymyxa might induce ginseng root rot if their population levels are high. Based on these results, it is recommended that the concentration of P. polymyxa should be monitored, when it is used as a biocontrol agent of ginseng, especially in the treatment of stored roots.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.312-312
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• 2017

The study was conducted to select optimal materials for promoting germination rate, high sprouting vigor by priming treatment using PEG 6000 (water potential -0.5 to 2.0 Mpa) and Azolla extracts (0.1, 1.0, and 10.0%) extracted by ethanol, distilled, and/or hot water in colored rice cultivars. Each rice seed (three black rice cultivars and two red rice cultivars) was soaked 24 and 48 hr including untreated control. In black rice, Joseongheugchal rice cultivar, azolla ethanol extract (0.1%) induced highest germination rate, germination speed was taken to 5 days in distilled water and to 3days in Azolla extracts extracted hot water. Otherwise, degree of bacterial inhibition (number of colony, $10^3cfu$) in dry seed, water soaking for 24hr, soaking with fungicide for 24hr and 48hr, soaking with fungicide and aeration for 24hr and 48 hr was 22, 500, 95, and 0.46, respectively. In order to minimize fungal inhibition, a method can be chosen to combination of soaking fungicide and aeration for 48 hr. In seed priming treatments using growth pouch, seed soaking with fungicide did not affect change of germination percentage and germination speed, it delayed only 2 or 4day in the Joseongheugchal rice cultivar. It differs from rice cultivars and priming materials, Azolla extract(0.1 to 1%) promotes seed germination percentage in the Ilpum, Hongjinju, and Joseonghuegchal, in addition, germination in Jeogjinju cultivar was only promoted by PEG solution(10 to 20%), otherwise, it showed much lower or inhibited on the germination in Heugjinju and Sinmyungheugchal rice cultivars. In a paddy field trial, seedling establishment rate by applying PEG6000 and azolla extract did not show significantly statistical difference. When it compared with untreated control, seedling establishment rate was increased over 50% in priming treatments. Interestingly, seedling establishment rate under azolla extract (0.1%) extracted with ethanol was promoted over 2.5 times compared to the control in a black rice, Joseongheugchal and red rice, Jeogjinju.

• 대한수의학회지
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• 제52권4호
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• pp.231-238
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• 2012

The expression profiles of inflammatory cytokines viz. interleukins (IL)-6, IL-8, IL-12, granulocyte macrophage-colony stimulating factor, interferon-${\gamma}$ and tumor necrosis factor-${\alpha}$ in response to subclinical mastitis in indigenous cattle breed Kankrej (n = 6), Gir (Bos indicus) (n = 12) and crossbred (Bos taurus${\times}$Bos indicus) (n = 7) were investigated using quantitative real time PCR. Significant correlation (p < 0.05) was observed between total bacterial load and somatic cell count (SCC) in all three breeds of cattle. All the cytokines were observed to be up-regulated compared to cows with healthy quarters, however, level of their expression varied among three breeds of cattle. In Kankrej most cytokines were found to be transcribed to higher levels than in other two breeds; the milk had higher load of bacteria but not so high SCC, implying that Kankrej has a higher inherent resistance against mastitis. The results of present study indicated that mammary glands of crossbred cattle are more sensitive to bacterial infection than indigenous breed of cattle as they elicit immune response at lower bacterial load and result into higher SCC. Research on identification of factors responsible for differentially expressed cytokines profiles and use of cytokines as immunomodulatory tools can pave way for formulating control strategies against bovine mastitis.

• Animal cells and systems
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• 제8권4호
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• pp.295-300
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• 2004

In the breeding colony of black-tailed gull, as nests of conspecific neighbors are very closely located, chicks are permanently exposed by sound and visual stimuli produced by adult conspecifics approaching their nests. The chicks, therefore, may need to learn ways to appropriately respond to their parents approach. In this study we experimentally manipulated sensory stimulation that is potentially provided by the parents to the offspring. Chicks incubated in the laboratory were exposed to a mew call of the conspecific adult. Then they were tested in three situations differing in sensory stimulation: 1) visual stimulation only, 2) auditory stimulation only, and 3) Simultaneous visual and auditory stimulations. We observed occurrence of different response of the chicks, which were categorized into three behaviors (begging call response, chirirah call and pecking behavior). We also investigated intensity of the chicks call in response to the different stimulations and the degree of response with age. The chicks exposed to only auditory stimulation made significantly more chirirah calls. The intensities (dB) of the mew call and chicks chirirah call were directly correlated. On the other hand, when chicks just saw the stuffed adult gull, they responded significantly more with a begging call and pecking behavior. In the situation of costimulation, the chicks responded with a begging call and pecking, but less frequently than visual stimulation only. The results suggest that young black-tailed gulls use call repertories to properly respond to parents behavior. Such results suggest an evolutionary process for uncreasing their survival rate in a group breeding site.

• 대한수의학회지
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• 제30권1호
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• pp.59-64
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• 1990

The present study was conducted in order to elucidate the asymptomatic carrier state of dermatophytes on the laboratory rodents in Korea during the period from August 1986 to April 1987. A total of 988 laboratory rodents, comprising 393 albino rats, 285 albino mice, 238 guinea pigs and 72 hamsters, were randomly selected for the isolation of dermatophytes from 6 research institutes and 2 breeding farms. And the mating experiments were performed to identified the perfect states of Trichophyton mextagrophytes isolated from albino rats. Dermatophytes were recovered from 94 of 393(23.9%) albino rats and from 3 of 5 colonies. Isolation rate of each colony was 38.4%, 32.0% and 9.8%, respectively, and the albino rats over 2 months old(28.2%) were higher than below 2 months old(2.9%) in the isolation rate of dermatophytes. Among 94 strains of dermatophytes isolated from albino rats, all the strains were identified T mentagrophytes, except 1 strain of Microsporum gypseum, and its perfect states were Arthroderma $vanbreuseghemii^+$.

• 한국응용곤충학회지
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• 제55권3호
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• pp.235-243
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• 2016

꽈리허리노린재는 가지과 및 메꽃과 기주에 피해를 주는 해충이다. 꽈리허리노린재는 실내의 $25^{\circ}C$ 조건에서 1세대는 평균 76일정도 소요되며, 성충으로 월동하기 때문에 수명이 길고, 일정한 주기 없이 알을 덩어리로 산란한다. 주로 잎 뒷면에 산란하며, 암컷 한 마리당 평균 195개, 최대 468개까지 산란하는 것으로 나타났다. 또한, 온도가 높아질수록 부화율은 높아지며, 발육기간은 짧아졌지만, $25^{\circ}C$를 제외한 다른 온도에서는 탈피율이 30%이하를 나타냈다. 위 결과를 토대로 선형모델로 추정한 결과 발육영점온도는 $13.9^{\circ}C$, 유효적산온도는 526.3DD를 나타냈다. 고추재배지에서 월동 성충이 6월 말 평균기온 $25.7^{\circ}C$에서 나타나기 시작하여, 9월초에 가장 높은 밀도를 나타내었다. 부화한 개체들은 성충이 될 때까지 이동성이 적었으며 밀집하여 분포하였다. 집단을 형성하는 요인을 알아보고자 Net cage와 Y-tube olfactometer를 이용한 행동실험 결과, 암컷은 수컷과 암컷이 모두 있는 곳을 선택하였지만, 수컷은 암컷과 수컷이 모두 없는 곳을 선택하였다. 수컷이 새로운 기주를 찾아 정착하면, 암컷은 기주를 독점한 동종이 많이 있는 기주를 찾아가는 교미와 관련된 행동을 나타냈으며, 통신화합물의 영향은 알 수 없었다. 집단이 미치는 영향을 알아본 결과 꽈리허리노린재는 좁은 공간에서 집단으로 사육시 약충의 발육기간이 길고 우화율이 높아지는 반면, 개체 사육시 발육기간이 짧고, 우화율이 낮게 나타났다. 반면에 넓은 공간에서는 집단으로 사육 시 약충의 발육기간은 짧고 우화율은 낮게 나타났다.