• Journal of Ecology and Environment
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• 제48권1호
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• pp.17-23
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• 2024

Background: Honey bees play a crucial role in pollination and ecological balance. Apis mellifera L. colonies, especially those located in specific geographic regions, such as the palm garden in Eastern Thailand, are susceptible to potential threats from microbial contaminants. Understanding and detecting microbial organisms in these beehives is essential for the preservation of bee health, honey production, and the broader ecosystem. However, the problem of microbial infection and antibiotic-resistant bacteria is more severe and continuously increasing, resulting in a health, economic, and social crisis. The purpose of this study is to determine the prevalence of microorganisms in A. mellifera beehives in palm gardens in Rayong province, Eastern Thailand. Results: Ten swabs in transport media were swabbed and obtained from different parts of each beehive (1 swab per beehive), for a total of 10 hives. Traditional microbial culture-based methods, biochemical tests, and antimicrobial susceptibility (disc-diffusion) tests were used to detect microbial organisms and antibiotic resistance in bacteria. The swab tests from nine beehives resulted in the detection of Gram-positive bacteria (63.64%), Gram-negative bacteria (27.27%), and fungi/yeast (9.09%). These microorganisms are classified as a group of coagulase-negative Staphylococcus spp. and made up 40.91% of the bacteria discovered. Other bacteria found were Coryneform bacteria (13.64%), Pantoea spp. (13.64%), Bacillus spp. (9.09%), yeast (9.09%), glucose non-fermentative Gram-negative bacilli (9.09%), and Pseudomonas spp. (4.55%). However, due to the traditional culture-based and 0biochemical tests usually used to identify the microbial organisms in clinical specimens and the limitation of identifying some environmental microbial species, the results of the antimicrobial susceptibility test cannot reveal if the organism is resistant or susceptible to the drug. Nevertheless, drug-sensitive inhibition zones were formed with each antibiotic agent. Conclusions: Overall, the study supports prevention, healthcare, and public health systems. The contamination of microorganisms in the beehives may affect the quality of honey and other bee products or even the health of the beekeeper. To avoid this kind of contamination, it is therefore necessary to wear personal protective equipment while harvesting honey and other bee products.

• 생명과학회지
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• 제23권10호
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• pp.1295-1303
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• 2013

현재까지 밝혀진 사실에 의하면 지구상에는 55개 phylum의 bacteria와 13개 phylum의 archaea가 존재하여 총 68개 phylum 있으며, 대장에는 9개 phylum의 미생물이 존재하여 일반 토양환경이나 해양환경에 비하여 상대적으로 낮은 미생물 다양성을 가지고 있다. 장내 미생물의 다양성은 Host의 고유특성(genetic background, sex, age, immune system, gut motility)과 식이(nondigestible carbohydrates fat, prebiotics or probiotics), 항생제 섭취 등으로 인하여 영향 받으며, 이러한 영향이 에너지 저장 과정과 유전자 발현을 영향을 주고 나아가 비만과 같은 대사질환에 영향을 미친다. Probiotics는 숙주의 장내 균총을 개선하여 건강에 유익함을 줄 수 있는 살아있는 미생물을 말하며, 주로 lactic acid bacteria들이 이용되어 왔다. 최근 probiotics를 이용한 설사나 과민성대장증후군 등과 같은 질병 치료를 위하여 bacteriotherapy가 활용되고 있다. Prebiotics는 장내 미생물을 선택적으로 조절할 수 있는 식품 성분으로 inulin, fructo-oligosaccharides, galacto-oligosaccharides, lactulose 등이 이용되고 있으며, 최근에는 비만, 항암과 관련하여 대장 내 식이섬유소의 이용과 단쇄지방산(short-chain fatty acids) 생산에 대한 관심이 집중되고 있다. 다양한 nondigestible carbohydrates와 prebiotics, probiotics에 의해서 조절되는 대장 내 특정 미생물 종을 규명하고, 이들 미생물 종이 생산하는 단쇄지방산과 같은 대사산물들과 질병과의 연관성 규명하는 대장 미생물 연구가 더욱 필요하다.

• KSBB Journal
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• 제21권4호
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• pp.273-278
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• 2006

박테리아 패터닝을 위한 혼성 아가로즈젤 마이크로 스탬프는 PDMS 몰드를 이용한 replica moding 공정을 이용하여 제작하였다. 완성된 스탬프를 박테리아를 잉크로 사용한 후, $50{\mu}m$ 원 모양을 가지는 2차원 박테리아 어레이를 구현할 수 있었다. 또한, 상기 방법을 통하여 실험 목적에 적합한 다양한 모양을 가지는 패턴을 쉽게 만들 수 있다. 패터닝된 박테리아의 형광 세기는 스팟과 주변간에 매우 높은 대조비를 이루며, 각각의 스팟 및 스팟간의 형광 세기가 매우 균일함을 보여 프린팅 시 매우 균일한 패턴을 얻을 수 있었다. 박테리아 패터닝을 할 경우 큰 문제점인 낮은 젖음성과 미끄럽고 작은 아가로즈젤 마이크로 스탬프를 취급의 어려움을 본 연구에서 제안한 혼성 아가로즈젤 마이크로 스탬프를 이용하여 해결할 수 있었다. 상기 방법의 가장 큰 장점은 세포를 이용한 패터닝의 경우 세포의 활성을 유지시키는 것인데 다량의 수분을 포함하는 아가로즈젤을 사용할 경우 세포의 활성을 유지시키면서 패턴을 구현할 수 있으므로 매우 중요한 기술로 생각된다. 본 연구에서 제안된 방법은 매우 재현성이 높으며, 편리하고, 빠르게 구현할 수 있어서 미생물 생태학, 세포와 표면간의 상호작용 그리고 세포를 바탕으로 하는 스크리닝 시스템에 활용 되어 질것으로 기대된다.

• 한국환경농학회지
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• 제40권1호
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• pp.67-72
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• 2021

BACKGROUND: Biological iron redox transformation alters iron minerals, which may act as effective adsorbents for arsenate [As(V)] in the environments. In the viewpoint of alleviating arsenate, microbial Fe(III) reduction was sought under high concentration of As(V). In this study, Fe(III)-reducing bacteria were isolated from the wild plant rhizosphere soils collected at abandoned mine areas, which showed tolerance to high concentration of As(V), in pursuit of potential agents for As(V) bioremediation. METHODS AND RESULTS: Bacterial isolation was performed by a series of enrichment, transfer, and dilutions. Among the isolated strains, two strains (JSAR-1 and JSAR-3) with abilities of tolerance to 10 mM As(V) and Fe(III) reduction were selected. Phylogenetic analysis using 16S rRNA genesequences indicated the closest members of Pseudomonas stutzeri DSM 5190 and Paenibacillus selenii W126, respectively for JSAR-1 and JSAR-3. Ferric and ferrous iron concentrations were measured by ferrozine assay, and arsenic concentration was analyzed by ICP-AES, suggesting inability of As(V) reduction whereas ability of Fe(III) reduction. CONCLUSION: Fe(III)-reducing bacteria isolated from the enrichments with arsenate and ferric iron were found to be resistant to a high concentration of As(III) at 10 mM. We suppose that those kinds of microorganisms may suggest good application potentials for As(V) bioremediation, since the bacteria can transform Fe while surviving under As-contaminated environments. The isolated Fe(III)-reducing bacterial strains could contribute to transformations of iron minerals which may act as effective adsorbents for arsenate, and therefore contribute to As(V) immobilization

• 치위생과학회지
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• 제24권2호
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• pp.97-106
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• 2024

Background: Periodontitis and peri-implantitis are diseases caused by pathogenic microorganisms that cause tissue damage and alveolar bone destruction resulting in the loss of teeth and implants. Due to the biological differences in the tissues surrounding the implants, peri-implantitis progresses more rapidly and intensely than periodontitis, underscoring the importance of understanding the characteristics and interactions of pathogenic bacteria. This study aimed to quantitatively analyze the pathogenic microorganisms associated with periodontitis and peri-implantitis in Korean patients and evaluate the correlation between these bacteria. Methods: A total of 98 (52 males and 46 females) were randomly selected and classified into three groups (healthy group [HG]=25; periodontitis group [PG]=31; and peri-implantitis group [PIG]=42). The relative expression levels of 11 pathogenic microorganisms collected from the gingival sulcus fluid were determined using multiplex real-time polymerase chain reaction. Results: Eikenella corrodens, Fusobacterium nucleatum, and Prevotella nigrescens were highly prevalent in the HG, PG, and PIG patients. The results of the relative quantitative analysis of microorganisms showed that all bacteria belonging to the green, orange, and red complexes were significantly more abundant in the PG and PIG than in the HG (p<0.05). Porphyromonas gingivalis in the red complex showed a positive correlation with all microorganisms in the orange complex (p<0.05). Campylobacter rectus in the orange complex showed a significant positive correlation with all microorganisms in the red complex, and with F. nucleatum, P. nigrescens, Prevotella intermedia, and Eubacterium nodatum (p<0.05). Conclusion: P. gingivalis, C. rectus, and F. nucleatum exhibit strong interactions. Removing these bacteria can block complex formation and enhance the prevention and treatment of periodontitis and peri-implantitis.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집B
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• pp.670-675
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• 2001

This paper is to propose image segmentation method based on chamfer algorithm. First, we get original image from CCD camera and transform it into gray image. Second, we extract maximum gray value of background and reconstruct and eliminate the background using surface fitting method and bilinear interpolation. Third, we subtract the reconstructed background from gray image to remove noises in gray image. Fourth, we transform the subtracted image into binary image using Otsu's optimal thresholding method. Fifth, we use morphological filters such as areaopen, opening, filling filter etc. to remove noises and isolated points. Sixth, we use chamfer distance or Euclidean distance to this filtered image. Finally, we use watershed algorithm and count microorganisms in image by labeling. To prove the effectiveness, we apply the proposed algorithm to one of Ammonia-oxidizing bacteria, Acinetobacter sp. It is shown that both Euclidean algorithm and chamfer algorithm show over-segmentation. But Chamfer algorithm shows less over-segmentation than Euclidean algorithm.

• Journal of Animal Science and Technology
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• 제59권11호
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• pp.27.1-27.7
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• 2017

Background: Cashew nut shell liquid (CNSL) is an agricultural byproduct containing alkylphenols that has been shown to favorably change the rumen fermentation pattern only under experimentally fixed feeding conditions. Investigation of CNSL potency in rumen modulation under a variety of feeding regimens, and evidence leading to the understanding of CNSL action are obviously necessary for further CNSL applications. The objective of this study was to evaluate the potency of CNSL for rumen modulation under different dietary conditions, and to visually demonstrate its surfactant action against selected rumen bacteria. Methods: Batch culture studies were carried out using various diets with 5 different forage to concentrate (F:C) ratios (9:1, 7:3, 5:5. 3:7 and 1:9). Strained rumen fluid was diluted with a buffer and incubated with each diet. Gas and short chain fatty acid (SCFA) profiles were characterized after 18 h incubation at $39^{\circ}C$. Monensin was also evaluated as a reference additive under the same conditions. Four species of rumen bacteria were grown in pure culture and exposed to CNSL to determine their morphological sensitivity to the surfactant action of CNSL. Results: CNSL supplementation decreased total gas production in diets with 5:5 and 3:7 F:C ratios, whereas the F:C ratio alone did not affect any gas production. Methane decrease by CNSL addition was more apparent in diets with 5:5, 3:7, and 1:9 F:C ratios. An interactive effect of CNSL and the F:C ratio was also observed for methane production. CNSL supplementation enhanced propionate production, while total SCFA production was not affected. Monensin decreased methane production but only in a diet with a 1:9 F:C ratio with increased propionate. Studies of pure cultures indicated that CNSL damaged the cell surface of hydrogen- and formate-producing bacteria, but did not change that of propionate-producing bacteria. Conclusion: CNSL can selectively inhibit rumen bacteria through its surfactant action to lead fermentation toward less methane and more propionate production. As CNSL is effective over a wider range of dietary conditions for such modulation of rumen fermentation in comparison with monensin, this new additive candidate might be applied to ruminant animals for various production purposes and at various stages.

• 미생물학회지
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• 제37권1호
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• pp.61-65
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• 2001

식물잎권의 잎표면세균에 대한 직접관찰과 이들을 분리시킨 용액 내 세균에 대한 간접관찰을 위하여 형광염료인 4', 6-diamidino-2-phenylindole(DAPI)와 acridine orange(AO)로 염색한 후 형광현미경을 사용하였다. AO로 염색한 잎표면은 배경형광이 진한 주홍색 이나 적색을 띠어 잎표면세균의 관잘 및 계수가 극히 힘들었으나 DAPI로 염색된 잎권세균은 뚜렷한 형광 영상을 나타내었다. 반면 잎표면세균 분리용액의 여과지에 대한 형광염색 결과는 DAPI와 AO 모두가 관찰이 가능하였다. 다만 DAPI가 AO에 비하여 형광 영상이 좀 더 뚜렷하였고 AO 염색과정에서는 염색된 여과지에 대한 세척과정이 필수적이었다. 최적의 DAPI 염색법은 잎과 여과지 모두가 5 $\mu$g/ml의 농도에서 5분 동안 염색하는 것이었다. 잎권의 형광현미경 관찰에 있어서 핵심적인 요소는 잎에서 나오는 수분을 최소화하는 것으로서 염색된 잎 시료를 거름종이 위에 올려놓고 공기 중에서 말리는 대신 $70^{\circ}C$를 유지한 건조기에서 2분 동안 말린 다음 바로 현미경으로 관찰하는 것이 가장 종은 방법인 것으로 확인되었다. 이렇게 확립된 형광현미경 관찰법을 떡갈나무의 잎권세균을 성공적으로 관찰하고 계수할 수 있었다.

• 대한환경공학회지
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• 제31권3호
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• pp.232-239
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• 2009

본 연구는 도시 하수처리장의 미생물 군집 내 항생제 내성 세균의 특징과 하천으로의 항생제 내성 세균 노출의 계절적 변화의 특성을 평가하였다. 일반 종속영양세균 배양을 위한 R2A agar (R2A)와 대장균군을 선택하여 배양하는 MacConkey sorbitol agar (MSA)에 항생제를 첨가 하여 제작한 배지에 하수처리장 시료를 도말하여 배양한 결과 모든 시료에서 다제 항생제 내성 세균을 검출 해 낼 수 있었다. Ampicillin과 sulfathiazole의 내성률이 다른 나라에 비해 높게 측정 되었으며 시료내 유기물의 정도, 사용된 배지에 따라 내성률이 다름을 볼 수 있었다. R2A 배지에서 분리된 다제 항생제 내성 세균은 모두 기존에 알려진 병원성 세균과 그 염기서열이 유사한 것으로 볼 때 병원성 세균의 항생제 내성 정도가 일반 세균보다 높음을 본 연구 결과로 보일 수 있었다. 또한 본 연구에서는 하수처리장이 하천에 미치는 유해성을 계절별로 관찰하여 전체 미생물중 항생제 내성 세균의 비율은 수온과 비례한다는 결과를 얻었다. 이 결과는 지구 온난화가 미생물 유해성을 증가시킬 가능성을 시사한다.

• 한국환경농학회지
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• 제40권4호
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• pp.248-259
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• 2021

BACKGROUND: Contaminated water was a major source of food-borne pathogens in various recent fresh produce-related outbreaks. This study was conducted to investigate the microbial contamination level and correlations between the level of sanitary indicator bacteria and the detection ratio of pathogens in agricultural water by logistic regression analysis. METHODS AND RESULTS: Agricultural water was collected from 457 sites including surface water (n=300 sites) and groundwater (n=157 sites) in South Korea from 2018 to 2020. Sanitary indicator bacteria (total coliform, fecal coliform, and Escherichia coli) and food-borne pathogens (pathogenic E. coli, E. coli O157:H7, Salmonella spp., and Listeria monocytogenes) were analyzed. In surface water, the coliform, fecal coliform, and E. coli were 3.27±0.89 log CFU/100 mL, 1.90±1.19 log CFU/100 mL, and 1.39±1.26 log CFU/100 mL, respectively. For groundwater, three kinds of sanitary indicators ranged in the level from 0.09 - 0.57 log CFU/100 mL. Pathogenic E. coli, Salmonella and Listeria monocytogenes were detected from 3%-site, 1.5%- site, and 0.6%-site water samples, respectively. According to the results of correlations between the level of sanitary indicator bacteria and the detection ratio of pathogens by logistic regression analysis, the probability of pathogen detection increased individually by 1.45 and 1.34 times as each total coliform and E. coli concentration increased by 1 log CFU/100mL. The accuracy of the model was 70.4%, and sensitivity and specificity were 81.5% and 51.7%, respectively. CONCLUSION(S): The results indicate the need to manage the microbial risk of agricultural water to enhance the safety of fresh produce. In addition, logistic regression analysis is useful to analyze the correlation between the level of sanitary indicator bacteria and the detection ratio of pathogens in agricultural water.