• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.12-12
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• 2017

Genetic improvement in potato can be carried out through several approaches, as sexual crosses, somatic hybridization, mutation and genetic engineering. Although the approach is different, but the goal is the same, to get a superior cultivar. Mutation and genetic engineering are very interesting methods for genetic improvement of potato plants. Mutation by gamma-ray irradiation have been performed to get some new potato cultivars which are more resistant to disease and have higher productivity. We have carried out a mutation of some potato cultivars and obtained some excellent clones to be potentially released as new superior cultivars. By the mutation method, we have released one potato cultivar for the French fries industry, and we registered one cultivar of potato for chips, and two cultivar for vegetable potatoes. Actually we are doing multi-location trial for three clones to be released as new cultivars. Through genetic engineering, several genes have been introduced into the potato plant, and we obtained several clones of transgenic potato plants. Transgenic potato plants containing FBPase gene encoding for fructose bisphosphatase, have a higher rate of photosynthesis and higher tuber productivity than non-transgenic plants. This result suggests that FBPase plays an important role in increasing the rate of photosynthesis and potato tuber productivity. Some transgenic potatoes containing the Hd3a gene are currently being evaluated for their productivity. Over expression of the Hd3a gene is expected to increase tuber productivity and induce flowering in potatoes. Transgenic potato plants containing MmPMA gene encoding for plasma membrane ATPse are more tolerant to low pH than non-transgenic plants, indicating that plasma membrane ATPase plays an important role in the potato plant tolerance to low pH stress. Transgenic potato plants containing c-lysozyme genes, are highly tolerant of bacterial wilt diseases caused by Ralstonia solanacearum and bacterial soft rot disease caused by Pectobacterium carotovorum. Expression of c-lyzozyme gene plays an important role in increasing the resistance of potato plants to bacterial diseases.

• 약학회지
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• 제53권4호
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• pp.194-200
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• 2009

Community-acquired antimicrobial resistant bacteria are an emerging problem whole world-wide. Generally, Hands are main mediator of pathogen transmission as compared with other body parts. So, the purpose of this research was to investigate the microbiological quality and antimicrobial susceptibilities of samples which were collected from the door knob and surface in public- and home-facilities, and also hand. Of total 191 samples, 71 samples (37%) were shown to be of high-level total bacterial count (>$10^8\;CFU/cm^2$). And presence of Staphylococcus and Enteric bacilli was observed in 61 samples (32%) and 76 samples (40%), respectively. Antimicrobial susceptibilities of staphylococcal isolates from the samples were tested for six different antimicrobial agents, which are in wide spread clinical use in Korea, as well as four new antimicrobials, daptomycin, linezolid, quinupristin/dalfopristin and tigecycline. Among staphylococcal isolates, antimicrobial resistance were observed in oxacillin (n=6), mupirocin (n=7), vancomycin (n=1), quinupristin/dalfopristin (n=2) and gentamicin (n=5). Fortunately, all the isolates were susceptible to new antimicrobial such as daptomycin, linezolid and tigecycline. Furthermore 4 Enterococcus faecalis were isolated from four hand samples, and all these isolates exhibited multidrug resistance to four different antimicrobial (oxacillin, quinupristin/dalfopristin, mupirocin, gentamicin). Also, 5 Escherichia coli were isolated from surface in home (n=3), door knob in public facilities (n=1) and hand (n=1). Escherichia coli isolated from hand was high-level resistant to tigecycline ($128{\mu}g$/ml) and gentamicin ($64{\mu}g$/ml).

• Journal of Species Research
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• 제7권3호
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• pp.202-209
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• 2018

Eight bacterial strains, 18JY8-13, 18JY13-16, 18JY43-7, 18JY12-7, 18JY1-1, 18JY1-7, 18JY15-3, and 18JY7-2 assigned to the phylum Firmicutes were isolated from a variety of soil samples collected in the Jeju Island, Korea. Cells of the eight strains were Gram-positive, aerobic and showed resistant to UV-radiation. Phylogenetic analysis based on 16S rRNA gene sequence revealed that strains 18JY8-13, 18JY13-16, 18JY43-7, 18JY12-7, 18JY1-1, 18JY1-7, 18JY15-3, and 18JY7-2 were most closely related to Bacillus paranthracis(99.9%), Bacillus paramycoides(99.6%), Bacillus australimaris(99.9%), Bacillus wiedmannii (100%), Bacillus halosaccharovorans(99.6%), Bacillus deserti(98.7%), Bacillus cereus (99.8%), and Bacillus albus(100%), respectively. This is the first report of these eight species in Korea.

• 식물병연구
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• 제9권1호
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• pp.39-41
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• 2003

Erwinia carotovora subsp. carotovora에 의한 배추 무름병은 배추에서 가장 큰 문제가 되고 있는 병중 하나이다. 본 연구는 배추 품종별 무름병 저항성을 조기에 검정하고자 실시하였다. 선발된 균주를 이용하여 세균현탁액과 mineral oil을 4:1로 혼합하여 배추의 중앙 기부에 10m1 관주 접종하는 mineral oil 접종법으로 접종하였다. 국내의 3개 종묘회사와 대학으로부터 분양 받은 43개의 배추품종 및 계통의 저항성 정도를 조사하였다. 그 결과 C3-26, C3-28, C3-29, C29-51-51-52는 저항성, 강타배추, 금촌얼갈이, 미니배추, 금빛, DB50, 지부, 평층, 산촌배추는 감수성인 것으로 나타났으며, 나머지는 중간정도의 저항성을 나타냈다.

• 방사선산업학회지
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• 제4권3호
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• pp.209-213
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• 2010

Bacterial blight is one of the most serious diseases of rice (Oryza sativa L.), and it has been known that Xanthomonas oryzae pv. oryzae (Xoo) causes this disease symptom. To develop resistance rice cultivars against Xoo, 3,000 lines of $M_3$ mutants, which were irradiated with gamma ray, were tested by 'scissor-dip method' primarily, and 191 putative resistant lines were selected. In $M_4$ generation, these lines were screened again with various ways such as measuring of symptom of bacterial blight in leaf, number of tiller, fresh weight, and phenotypic segregation ratio in next generation. Finally, six resistance lines were selected. RT-PCR analysis revealed that these lines displayed high level of R-genes such as Xa21, Pi36, and Pi-ta. These results indicate that mutations by gamma ray cause disruptions of regulatory signal transduction systems of these R-genes. Furthermore, these selected mutants could be useful for the development of rice cultivar resistant to Xoo.

• 한국환경농학회지
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• 제38권3호
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• pp.185-196
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• 2019

BACKGROUND: This study investigated the effects of rice genetically modified to be resistant against rice blast and rice bacterial blight on the soil microbial community. A comparative analysis of the effects of rice genetically modified rice choline kinase (OsCK1) gene for disease resistance (GM rice) and the Nakdong parental cultivar (non-GM rice) on the soil microbial community at each stage was conducted using rhizosphere soil of the OsCK1 and Nakdong rice. METHODS AND RESULTS: The soil chemistry at each growth stage and the bacterial and fungal population densities were analyzed. Soil DNA was extracted from the samples, and the microbial community structures of the two soils were analyzed by pyrosequencing. No significant differences were observed in the soil chemistry and microbial population density between the two soils. The taxonomic analysis showed that Chloroflexi, Proteobacteria, Firmicutes, Actinobacteria, and Acidobacteria were present in all soils as the major phyla. Although the source tracking analysis per phylogenetic rank revealed that there were differences in the bacteria between the GM and non-GM soil as well as among the cultivation stages, the GM and non-GM soil were grouped according to the growth stages in the UPGMA dendrogram analysis. CONCLUSION: The difference in bacterial distributions between Nakdong and OsCK1 rice soils at each phylogenetic level detected in microbial community analysis by pyrosequencing may be due to the genetic modification done on GM rice or due to heterogeneity of the soil environment. In order to clarify this, it is necessary to analyze changes in root exudates along with the expression of transgene. A more detailed study involving additional multilateral soil analyses is required.

• 한국미생물·생명공학회지
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• 제49권4호
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• pp.587-593
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• 2021

Infertility is a key issue affecting mood and behavior in men. Microorganisms are one of the primary etiological agents that may be associated with infertility. The objective of the present study was to identify bacterial causative agents from the semen of infertile subjects and determine the effect of bacterial infection on sperm quality, as well as determine the susceptibility of these bacteria to drugs. Forty semen samples from 30 infertile patients and 10 fertile individuals were collected. The pH, volume, motility, and concentration of semen were analyzed. The samples were processed and identified by biochemical testing using API identification kits. The antibiotic susceptibility pattern was determined using the disc diffusion method. Abnormal sperm quality was observed. The mean age of the individual and their sperm morphology, concentration, progressive motility, pH level, and pus cell content were 31.9 years, 2.7%, 10.4 million/ml, 27.3%, 8.3, and 5.7, respectively. Among the tested samples, oligoasthenozoospermia was found to show the highest occurrence, at 27/30 samples, followed by teratozoospermia, at 25/30 samples, and asthenozoospermia, at 22/30 samples. Of the tested infertile patients' sperm, 19, 6, and 5 isolates were identified as Escherichia coli, Klebsiella pneumonia, and Staphylococcus epidermidis, respectively. The results also revealed multi-drug resistance in the bacteria. Compared to that shown by the other tested antibiotics, amikacin showed higher activity against all isolated bacteria. However, the bacteria exhibited maximum resistance against gentamicin, cefotaxime, levofloxacin, and ampicillin. In conclusion, leukocytospermia and bacterial infections are possibly responsible for sperm abnormalities. Multi-drug resistant bacteria were detected. Gentamicin, cefotaxime, levofloxacin and ampicillin were shown the highest resistance, while amikacin was the most effective antimicrobial agent against the isolated bacteria.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2023년도 춘계학술대회
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• pp.32-32
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• 2023

Cadmium and salt exposure to crops is considered vulnerable for production as well as consumption. To address these challenges, the current study aimed to mitigate the toxicity induced by salt and cadmium in soybean plants through the application of bacterial strain Bacillus safensis KJW143 isolated from the rhizosphere of oriental melon..The bioassay analysis revealed that KJW143 is a highly salt-tolerant and cadmium-resistant (Cd) strain with an innate ability to produce melatonin, gibberellin (GA3), Indole-3-Acetic Acid (IAA), and organic acids (i.e., acetic, succinic, lactic, and propionic acids). Soybean plants at 20 days old were treated with KJW143 in a different form (pellet, broth, and together) and their effect on plant performance was investigated. Inoculation with KJW143enhanced plant biomass and growth attributes in soybean plants compared to the control (non-treated). In particular, we observed that only pellet-treated showed 65%, 27.5%, and 28.7% increase in growth (shoot fresh weight) compared to broth, broth with pellet, and control. In addition, bacterial strain KJW143 treatment (only pellet) modulated the physiochemical apparatus of soybean plants by increasing glucose (390%), arabinose (166%), citric acid (22.98%) and reducing hydrogen peroxide (29.7%), catalase (32.1%), salicylic acid (25.6%) compared to plants with combined stressed plants (cd and salinity). These findings suggest that bacterial strain KJW143 could be usedas a biofertilizer to minimize the probable risk of heavy metal and salinity stress on crops.

• The Journal of Advanced Prosthodontics
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• 제12권4호
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• pp.233-238
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• 2020

PURPOSE. This study aims to compare the marginal fitness of two types of implant-supported fixed dental prosthesis, i.e., cementless fixation (CL.F) system and cement-retained type. MATERIALS AND METHODS. In each group, ten specimens were assessed. Each specimen comprised implant lab analog, titanium abutment fabricated with a 2-degree tapered axial wall, and zirconia crown. The crown of the CL.F system was retained by frictional force between abutment and relined composite resin. In the cement-retained type, zinc oxide eugenol cement was used to set crown and abutment. All specimens were sterilized with ethylene oxide, immersed in Prevotella intermedia culture in a 50 mL tube, and incubated with rotation. After 48 h, the specimens were washed thoroughly before separating the crown and abutment. The bacteria that penetrated into the crown-abutment interface were collected by washing with 500 µL of sterile saline. The bacterial cell number was quantified using the agar plate count technique. The BacTiter-Glo Microbial Cell Viability Assay Kit was used to measure bacterial adenosine triphosphate (ATP)-bioluminescence, which reflects the bacterial viability. The t-test was performed, and the significance level was set at 5%. RESULTS. The number of penetrating bacterial cells assessed by colony-forming units was approximately 33% lower in the CL.F system than in the cement-retained type (P<.05). ATP-bioluminescence was approximately 41% lower in the CL.F system than in the cement-retained type (P<.05). CONCLUSION. The CL.F system is more resistant to bacterial penetration into the abutment-crown interface than the cement-retained type, thereby indicating a precise marginal fit.

• 한국육종학회지
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• 제41권3호
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• pp.244-251
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• 2009

벼흰잎마름병 저항성 유전자 Xa3을 침해하는 K3a 균계를 포함하여 24개의 균주에 대한 단일저항성 유전자와 2개 이상의 주동저항성 유전자가 결합된 계통에 대한 결과를 요약하면 다음과 같다. 1. 벼흰잎마름병 저항성 유전자 Xa3, Xa4, xa5 및 Xa7은 K1, K2, K3 균계에 저항성 반응을 보이며 K3a 균계에 대하여 Xa4는 중도저항성, xa5 및 Xa21은 저항성반응을 보였다. 2. 벼흰잎마름병 저항성 유전자 Xa3을 침해하는 24개 균주들에 대해 이병성을 보인 유전자는 Xa1, Xa2, xa8, Xa10, Xa11 및 xa13이었고, 저항성을 보인 유전자는 Xa4, xa5 및 Xa21이었다. Xa7 유전자는 반복친의 유전적 배경에 따라서 저항성 반응이 달랐다. 3. Xa4+xa5, Xa4+xa13, Xa4+Xa21, xa5+xa13, xa5+Xa21, xa13+Xa21, Xa4+xa5+xa13, Xa4+xa5+Xa21, Xa4+xa13+Xa21, xa5+xa13+Xa21, Xa4+xa5+xa13+Xa21 및 Xa3+xa5 등 2개 이상의 단일 주동 저항성 유전자가 결합되었을 때 K1, K2, K3 균계 및 Xa3 유전자를 침해하는 24개의 균주들에 강한 저항성 반응을 보였다. 4. Xa3 및 xa13 유전자는 24개의 균주들에 이병성을 보이지만 xa5, Xa4, Xa21 유전자와 결합되었을 때 단일저항성이 증가되었고, 중도저항성 반응을 보이는 Xa4 유전자는 xa5, Xa21 유전자와 결합되었을 때 고도의 저항성 반응을 보였다.