• 한국약용작물학회지
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• 제12권1호
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• pp.60-66
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• 2004

한국산 옻나무속 6종에 대하여 분자식물학적 방법으로 계통유연관계를 확인하기 위하여, nrDNA의 ITS 구간과 cpDNA rbcL 염기서열을 사용하여 계통분석한 결과 ITS 1의 길이는 $246{\sim}253\;bp$이었고, ITS 2는 $234{\sim}244\;bp$이었다. ITS 1의 길이는 Rhus sylvestris와 R. succedanea에서 246 bp로 가장 작았으며, R. verniciflua에서 253 bp로 가장 긴 것으로 나타났다. ITS 2의 길이는 R. verniciflua가 234 bp로 가장 짧았으며, R. trichocarpr가 244 bp로 가장 길게 나타났다. 이들 분류군의 G+C Content는 ITS 1에서는 $58.0{\sim}68.13%$의 범위를 나타냈고, ITS 2에서는 $59.75{\sim}68.46%$로 나타나 두 구간이 비슷한 비율을 보이고 있었다. ITS 1에서의 G+C content는 R. sylvestris가 58.0%로 가장 낮았으며, 가장 높은 값은 R. ambigua가 68.13%로 확인되었다. ITS 2에서는 외군인 Cotinus coggygria가 59.75%로 가장 낮았으며, R. ambigua가 68.46%로 가장 높게 나타났다. 한국산 옻나무 속에서 ITS 염기서열은 일반적으로 피자식물이 갖는 G+C content 범위 안에 포함되는 것으로 확인되었다. 한편, rbcL의 길이는 1,428 bp로 모든 종에서 동일하였다. 또한 rbcL의 G+C content는 $43.56%{\sim}43.77%$로 나타나 종간에 거의 차이가 없음을 확인하였다. 연구결과 rbcL gene은 옻나무속의 종간 계통유연관계를 해석하는데 유용하지 않았으며, ITS 1 구간의 염기서열 변이는 향후 옻나무속을 분류할 때 신속하게 분류할 수 있는 분류 marker로 이용할 수 있다고 판단되었다.

• Journal of Microbiology and Biotechnology
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• 제12권2호
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• pp.312-317
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• 2002

Indigenous lactobacilli were isolated from vaginas of Korean women for possible use in ecological treatment of bacterial vaginosis. Vaginal swab samples were obtained from a gynecological clinic and streaked on Rogosa SL agar plates to select the most predominant lactobacilli in each sample. The preliminary identification of the isolates as lactobacilli was based on microscopic observation of Gram-positive rod-shaped cell morphology. The initial characterization was performed on 108 isolates in terms of their cell surface hydrophobicity (CSH), antimicrobial activity, and hydrogen peroxide (H₂O₂) production capability, and 10 isolates were then selected for further molecular identification. For a rapid procedure to identify lactobacilli, polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analyses of the l6S rRNA genes were applied. The 10 selected lactobacilli and 9 different reference strains of Lactobacillus spp. were characterized by PCR-RFLP where the amplified l6S rDNA was digested with 7 different restriction endonucleases prior to analysis. DNA sequencing of the 16S rRNA gene of one particular isolate, KLB 46, that had been identified as L. crispatus by the PCR-RFLP analysis, further confirmed its identity as L. crispatus.

• Ocean and Polar Research
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• 제28권2호
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• pp.107-117
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• 2006

Freshwater algal studies in North polar environments are relatively few. This study presented the algal-flora, -biomass and genetic features of dominant cells collected from temporary ponds around the Polar Research Station (PRS), Norway. Water samples were collected from 4 stations around PRS, and analyzed for their environmental and biological variables. Water temperature, salinity and conductivity ranged from 5 to $10^{\circ}C$, 0.1 to $0.3%_{\circ}$ and 0.21 to $0.36{\mu}S/cm$, respectively. Chlorophyll a concentration ranged from 1.8 to $11.1{\mu}g/l$, and that of the size-fractionated cells was recorded from 0.7 to $1.1{\mu}g/l$ in picoplankton 0.3 to $6.5{\mu}g/l$ in nanoplankton, and 0.4 to $3.9{\mu}g/l$ in microplankton respectively. Algal flora in the present study was recorded as 10 genera, in which Chlamydomonas, particularly, was dominant in all studied sites. By comparison of Chlamydomonas 18S rDNA sequences, including two isolates from PRS, they formed a distinct clade against others: sequence similarity was significantly low (<97.2%) with C. noctigama, being the highest score by BLAST search in GenBank. This study was valuable for basic knowledge regarding the freshwater algae around PRS and their genetic information.

• 한국미생물·생명공학회지
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• 제37권3호
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• pp.189-196
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• 2009

Bacteria were isolated from roots of plants belonging to family Solanaceae and Gramineae, inhabited in Dokdo island. Fifty six endospore-forming bacteria grown on tryptic soy broth (TSB) agar medium and 23 nitrogen-fixing bacteria (NFB) grown on nitrogen free agar medium were isolated, respectively. The isolates were partially identified by analyzing the 16S rDNA and categorized into phylogenetic groups. The 16S rDNA sequences of each identified isolates were compared with sequences of each type strains to analyze phylogenetic relationship by phylogenetic tree. As a result, endospore-forming bacteria and nitrogen-fixing bacteria were classified into 4 and 6 lineage groups, respectively. Among these isolated, 18 were presumed to be novel species candidates based on the similarity (lower than 98%) analysis of the l6S rDNA sequences.

• 한국동물위생학회지
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• 제33권3호
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• pp.223-231
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• 2010

A total of 191 samples collected from the commercial swine farms located in Chungnam province were investigated by PCR to estimate the prevalence of Lawsonia (L.) intracellularis infection. In the group of the pigs with proliferative enteritis, 14 (93.3%) of 15 intestinal samples and 12 (80.0%) of 15 feces were positive in PCR. In contrast, a relatively low positive rate (18.0%, 29 of 161 samples) was determined in the group of normal healthy pigs. The group of pigs over 120 days showed the highest positive rates (26.8%, 15 of 56 samples). In the comparison of the sequences of 210bp for species specific fragments and 301bp for outer membrane protein, the isolates (L1. L2) showed almost 100% identity with the reference L. intracellularis (L08049, USA). For the sequences of partial 16s rDNA, the homologies among the 5 isolates (L1-L5) were 97.4% to 99.3%, and those of 5 sequences (L1-L5) versus 5 overseas reference strains of L. intracellularis ranged from 98.6% to 99.8%. In the comparison of the nucleotide sequences among 5 isolates and other species in Desulfovibrionales showed 82.4 to 99.5% identities. The 5 isolates shared relatively low identities (76.9% to 84.4%) with the species of alpha-proteobacteria. In phylogenetic analysis based on the 16s rDNA sequences, all of the 5 isolates (L1-L5) were located in the same branch with the strains of L. intracellularis that were previously isolated from the pigs in USA and China. Seven strains of Desulfovibrio sp. were clustered in the neighboring branches, whereas alpha and gamma Proteobacteria showed distant relationship with L. intracellularis strains. The present findings suggest that L. intracellularis infection is endemic in the swine farms in the regions, and that the domestic isolates maintained very limited genetic variation.

• 한국자원식물학회지
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• 제30권6호
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• pp.654-661
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• 2017

Dual-color fluorescence in situ hybridization karyotype analysis was created using repetitive sequences including two types of rDNA repeats (45S and 5S rDNAs) and Arabidopsis-type telomere sequence repeats. The somatic metaphase cells of Carthamus tinctorius were observed as diploids (2n=2x=24). A symmetrical or slightly asymmetrical karyotype with seven pairs of metacentric and five pairs of submetacentric chromosomes was observed. The lengths of the somatic metaphase chromosomes ranged from 4.18 to $6.53{\mu}m$, with a total length of $60.71{\mu}m$. One locus of 45S rDNA was located on the pericentromeric regions of three pairs of chromosomes and the other pair was situated on the terminal regions of the short arms of a single pair of chromosomes. One locus of 5S rDNA was detected on the interstitial regions of the short arms of two pairs of chromosomes. Arabidopsis-type telomeric repeats were detected on the terminal regions of all pairs of chromosomes. Co-localization of loci between telomeric repeats and 45S rDNA was observed in a single pair of chromosomes. The results provide additional information for the existing physical mapping project of C. tinctorius and will also serve as a benchmark to a more intricate cytogenetic investigation of C. tinctorius and its related species.

• Journal of Microbiology
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• 제42권1호
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• pp.9-13
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• 2004

Culture-independent approaches, based on 16S rDNA sequences, are extensively used in modern microbial ecology. Sequencing of the clone library generated from environmental DNA has advantages over fingerprint-based methods, such as denaturing gradient gel electrophoresis, as it provides precise identification and quantification of the phylotypes present in samples. However, to date, no method exists for comparing multiple bacterial community structures using clone library sequences. In this study, an automated method to achieve this has been developed, by applying pair wise alignment, hierarchical clustering and principle component analysis. The method has been demonstrated to be successful in comparing samples from various environments. The program, named CommCluster, was written in JAVA, and is now freely available, at http://chunlab.snu.ac.kr/commcluster/.

• 한국미생물·생명공학회지
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• 제37권4호
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• pp.350-354
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• 2009

해운대 연안에서 그람 음성균이면서 알긴산 분해효소를 생산하는 세균을 분리하였다. 분리된 N7151-6 균주의 성장을 위한 최적 온도는 $30^{\circ}C$, 최적 pH는 8.0으로 조사되었다. 또한 0-7%(w/v) NaCl 농도에서도 성장 가능하다. 16S rDNA 염기 서열 분석과 생화학적 분석에 의해 이 균주는 Pseudomonas 속으로 동정되어 Pseudomonas sp. N7151-6으로 명명하였다. Pseudomonas sp. N7151-6에서 생산하는 알긴산 분해효소를 한외여과(ultrafilteration; MWCO=30 kDa) 방법에 의해 부분정제하였다. 분리된 효소의 최적 pH는 7.0으로 최적 온도는 $30^{\circ}C$로 조사 되었다. pH 5.0에서 9.0까지 이 효소는 안정하였으며, $23^{\circ}C$에서 $37^{\circ}C$까지의 범위에서도 안정성을 보여주었다. 알긴산 분해효소의 전체 활성은 110 unit/L이었다.

• 한국육종학회지
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• 제43권4호
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• pp.252-259
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• 2011

Conventional staining and fluorescence in situ hybridization (FISH) karyotypes of the non-genetically modified (GM) parental rice line, 'Nakdong' (Oryza sativa L. japonica), and its four GM rice lines, LS28 (event LS30-32-20-1), Cry1Ac1 (event C7-1-9-1), and LS28 ${\times}$ Cry1Ac1 (events L/C1-1-3-1 and L/C1-3-1-1) were analyzed using 5S and 45S rDNAs as probes. Both parental and transgenic lines were diploids (2n=24) with one satellite chromosome pair. The lengths of the prometaphase chromosomes ranged from 1.50 to $6.30{\mu}m$. Four submetacentric and eight metacentric pairs comprised the karyotype of 'Nakdong' and its four GM lines. One pair of 5S rDNA signals was detected near the centromeric region of chromosome g in both the parental and transgenic lines. The 45S rDNA signals were detected on the secondary constrictions of the satellite chromosome pair in both the parental and transgenic lines. There was no significant difference in chromosome size, length, and composition between 'Nakdong' and its four GM lines. This research was conducted as a preliminary study for chromosomal detection of transgenes in GM rice lines and would be useful for their breeding programs.

• The Korean Journal of Ecology
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• 제27권5호
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• pp.283-289
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• 2004

2002년 1월부터 12월까지 매월 전북 군산시 인근에 위치한 금강호를 대상으로 항생제 내성균의 월별분포변화와 조사기간 중 분리된 균주를 동정하였다. 종속영양세균의 연중 분포는 4.1±1.0 × 10²- 6.7±1.1×10³ cfu mL/sup -1/의 범주에서 변화하였다. 항생제 내성균의 년중 분포는 ampicillin 내성균의 경우, 1.5±0.7×10-4.3±0.3×10³ cfu mL/sup -l/, chloramphenicol 내성균의 경우, 0-6.4 ±0.4 ×10² cfu mL/sup -1/, gentamicin내성균의 경우, 0-2.8±0.3×10³ cfu mL/sup -1/, kanamycin내성균의 경우, 0-4.5±1.0×10³ cfu mL/sup -1/, 그리고 streptomycin 내성균은 1.0±0.4×10-2.3±0.5×10³ cfu mL/sup -1/의 범주에서 변화하였다. 조사된 항생제 내성균들 중 ampicllin 내성균이 모든 정점에서 가장 높은 균체수를 나타냈다 조사기간 중 60균주의 항생제 내성균이 분리되었으며, 그 중 그람양성 세균은 6균주, 그람음성세균은 54균주를 차지하였다. 항생제 내성균으로 분리된 균주는 Pseudomonas 속, Aeromonas 속, 그리고 Bacillus 속과 Stenotrophomonas 속 등이 우점으로 나타났으며, 이외에도 Enterobacter 속, Sphingobium 속, Variovorax 속, 그리고 Serratia 속, Acinetobacter 속, Mycoplana 속, Psychrobacter 속과 , Xanthomonas 속 등이 포함되었다. 동정된 균들은 ampicillin, kanamycin, chloramphenicol, streptomycin, gentamicin 순으로 높은 내성을 나타났다.