• Carbon letters
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• 제8권3호
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• pp.184-190
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• 2007

Carbon Nano Tubes could be either metallic or semi-conducting in nature, depending on their diameter. Its photocatalytic behavior has given an impetus to use it as an anti-microbial agent. More than 95% Escherichia coli and Staphylococcus aureus bacteria got killed when exposed to Carbon Nano Tubes for 30 minutes in presence of sunlight. Carbon Nano Tubes are supposed to have smooth surface on to which it accumulates positive charges when exposed to light. The surface that is non illuminated has negative charge. At the cellular level microorganisms produce negative charges on the cell membrane, Therefore damaging effect of multi walled carbon nano tubes (exposed to light) on the microorganisms is possible. In this paper, photo catalytic killing of microbes by multi walled carbon nano tubes is reported. Killing was due to damage in the cell membrane, as seen in SEM micrographs. Moreover biochemical analysis of membrane as well as total cellular proteins by SDS PAGE showed that there was denaturation of membrane proteins as well as total proteins of both the microbes studied. The killed microbes that showed a decrease in number of protein bands (i.e. due to breaking down of proteins) also showed an increase in level of free amino acids in microbes. This further confirmed that proteins got denatured or broken down into shorter units of amino acids. Increased level of free amino acids was recorded in both the microbes treated with multi walled carbon nano tubes and sunlight.

• International Journal of Industrial Entomology and Biomaterials
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• 제14권2호
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• pp.147-150
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• 2007

Abaecin is a largest member of the proline-rich anti-microbial peptide family found only in the hymenopterans. A cDNA of abaecin was previously isolated and cloned from Bombus ignitus: the mature peptide of Bombus ignitus abaecin was composed of 39 amino acid residues. In the present study, we determined the antibacterial effect of B. ignitus abaecin synthesized at several lengths against several bacteria by radial diffusion assay. The 37-mer peptide (Ab37) inhibited the growth of Gram-negative bacteria Escherichia coli ML-35, Pseudomonas aeruginosa and Salmonela typhimurium, but showed limited inhibitory activity toward Gram-positive bacteria, except for Micrococcus luteus. The truncated 26-mer peptide (Ab26), which was synthesized after truncating some amino acid residues at both N-terminus and C-terminus from the Ab37 peptide, still showed equivalent antibacterial activity to the Ab37. On the other hand, several further truncated peptides exhibited lower activity then did Ab37 peptide.

• Journal of Plant Biotechnology
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• 제47권1호
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• pp.100-106
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• 2020

Coix lacryma-jobi (Hanjeli) is known to posses anti-microbial properties. Therefore, phytochemical compounds of C. lacryma-jobi have been studied to produce novel antimicrobial agents as treatments against antibiotic-resistant bacteria.The objective of this study was to determine the phytochemical composition and antibacterial activity of the C. lacryma-jobi oil against Escherichia coli, Staphylococcus aureus, and Bacillus subtilis. The phytochemical composition of the oil was determined via gas chromatography mass spectrophotometry (GC-MS). Moreover, agar disk and agar well diffusion were employed to screen the antibacterial activity of the oil. An agar well diffusion test was implemented to determinate MIC's (minimum inhibitory concentrations). Dodecanoic acid, tetradecanoic acid, 2,3-dihydroxypropylester, 1,3-dioctanoin, N-methoxy-N-methyl-3,4-dihydro-2H-thiopyran6-carboxamide, propanamide, 5-Amino-1-(quinolin-8-yl)-1,2,3-triazole-4-carboxamide, and pyridine were identified in the C. lacryma-jobi oil. The MIC value of the oil was 0.031 g/L and the MBC of the oil was 0.125 g/L effective in all test bacteria. Dodecanoic acid displayed inhibitory activity against gram-positive and gram-negative bacteria. Therefore, our research demonstrated C. lacryma-jobi (Hanjeli) oil exhibited antibacterial activity against E. coli, S. aureus, and B. subtilis. These research suggest that C. lacryma-jobi root oil could be used for medicinal purposes; however clinical and in vivo tests must be performed to evaluate its potential as an antibacterial agent.

• 한국식품조리과학회지
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• 제15권4호
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• pp.410-417
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• 1999

우리나라 야산에서 쉽게 구할 수 있는 구황 식물인 질경이를 메탄올과 여러 용매로 추출하여 식품 부패 미생물에 대한 항균력을 실험하고 그 항균활성 물질을 분석하여 다음과 같은 결과를 얻었다. 질경이의 메탄올 추출물은 2000$\mu\textrm{g}$/ml 농도에서 B. subtilis 및 V. parahaemolyticus의 증식을 100% 억제하였다. 그리고 질경이의 ethylacetate 분획물은 1000$\mu\textrm{g}$/disc 농도에서 5종의 모든 실험 균주에 대하여 8.5~11mm 크기의 clear zone을 형성하여 가장 높은 항균력을 보였다. 질경이의 ethylacetate 분획물을 silica gel column chromatography와 TLC로 분리하여 얻은 fraction을 5가지 실험 균주에 대하여 항균 실험을 한 결과 3rd 분획물 중 4번째 분획물이 250$\mu\textrm{g}$/disc 농도에서 모든 균주에 대하여 10 mm 이상의 clear zone을 나타내었다. 항균력을 보인 질경이의 ethylacetate 3rd fraction No. 4를 HPLC로 단일 분리하여 얻은 peak IV로 부터 $^1$H-NMR 및 GC-MSD로 동정한 결과 hexadecanoic acid로 동정되었다.

• 한국식품과학회지
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• 제34권3호
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• pp.466-471
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• 2002

고추장의 저장성 향상을 목적으로 숙성이 완료된 고추장에 마늘이나 알콜, 키토산, K-sorbate, 겨자를 첨가하거나 저온살균 처리를 하여 포장하고 $30^{\circ}C$에서 24주간 저장하면서 화학성분의 변화를 비교하였다. 고추장의 pH는 저장 중에 저하하였고 적정산도는 저장 8주 이후에 감소하나 겨자와 마늘 첨가구에서 높았다. 환원당은 저장 $16{\sim}20$주에 증가하여 K-sorbate와 알콜 첨가구에서 높았고, 알콜의 증가는 대조구와 키토산 첨가구에서 심하였다. 아미노태 질소 함량은 알콜이나 마늘, K-sorbate, 겨자 첨가구에서 낮았다. 유리 아미노산은 저장 중에 증가하였고 저온 살균구와 마늘, 알콜 첨가구에서 많았다. $30^{\circ}C$에서 24주 저장한 고추장의 관능치는 유의성은 없으나 맛은 K-sorbate와 마늘, 겨자 첨가구, 색은 저온 살균구와 K-sorbate, 알콜 첨가구, 향기는 마늘과 키토산 첨가 고추장이 우수하여 종합적인 기호도에서 K-sorbate와 마늘, 알콜 첨가 고추장이 좋았다.

• Restorative Dentistry and Endodontics
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• 제44권1호
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• pp.8.1-8.7
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• 2019

Objectives: Irrigants are imperative in endodontic therapy for the elimination of pathogens from the infected root canal. The present study compared the antimicrobial efficacy of octenidine dihydrochloride (OCT) with chlorhexidine (CHX) and sodium hypochlorite (NaOCl) against Staphylococcus epidermidis (S. epidermidis) for root canal disinfection. Materials and Methods: The minimum inhibitory concentration (MIC) was obtained using serial dilution method. The agar diffusion method was then used to determine the zones of inhibition for each irrigant. Lastly, forty 6-mm dentin blocks were prepared from human mandibular premolars and inoculated with S. epidermidis. Samples were randomly divided into 4 groups of 10 blocks and irrigated for 3 minutes with saline (control), 2% CHX, 3% NaOCl, or 0.1% OCT. Dentin samples were then collected immediately for microbial analysis, including an analysis of colony-forming units (CFUs). Results: The MICs of each tested irrigant were 0.05% for CHX, 0.25% for NaOCl, and 0.0125% for OCT. All tested irrigants showed concentration-dependent increase in zones of inhibition, and 3% NaOCl showed the largest zone of inhibition amongst all tested irrigants (p < 0.05). There were no significant differences among the CFU measurements of 2% CHX, 3% NaOCl, and 0.1% OCT showing complete elimination of S. epidermidis in all samples. Conclusions: This study showed that OCT was comparable to or even more effective than CHX and NaOCl, demonstrating antimicrobial activity at low concentrations against S. epidermidis.

• 한국콘텐츠학회논문지
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• 제20권12호
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• pp.454-459
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• 2020

구강질환의 주된 원인은 치면세균막 형성이며, 억제하는 방법의 하나로 화학제재로 된 구강세정제를 사용한다. 하지만 화학제재는 부작용이 발생할 염려가 있어 본 연구에서 천연물질인 대나무 추출물의 구강미생물에 대한 항균효과를 검증하고자 하였다. 대상자는 대구에 소재한 대학교 학생으로 대조군, 실험군 각 15명씩을 선정 후 대조군은 증류수 양치액, 실험군은 대나무 추출물의 사용 전, 후의 구강병원성 미생물의 변화를 비교하였다. 수집된 자료는 SPSS Windows ver. 20.0을 이용하여 분석하고, 통계적 유의수준은 p<0.05로 하였다. 그룹간의 양치액 사용 후 병원성 미생물의 변화차이를 알아보기 위해 Mann-Whitney test를 실시하였으며, 총 병원미생물수가 실험군은 -1.27±1.26, 대조군이 0.26±1.21로 높은 것으로 나타났고 이는 통계적으로 유의한 것으로 나타나 결과적으로 부작용이 적으면서 우수한 구강양치액의 개발에 기초자료를 제공할 것으로 기대된다.

• 한방재활의학과학회지
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• 제31권1호
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• pp.47-57
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• 2021

Objectives This study was conducted to confirm the possibility of Clostridium difficile infection (CDI) treatment through natural herbal medicines. Methods After screening a total of 77 herbal medicines through the paper disc agar diffusion method, we selected the herbal medicines that showed a effectiveness compared to the positive control vancomycin. Afterwards, drugs that showed inhibitory effects compared to C. difficile without inhibition of Bifidobacterium bifidum and Lactobacillus plantarum, known as beneficial bacteria, were selected and minimal inhibitory concentration (MIC) was confirmed by applying the Broth microdilution method. Results The Coptidis Rhizoma, well known for its antimicrobial effect, was found to have antimicrobial effects on C. difficile, but also had inhibitory effects on the beneficial bacterium B. bifidum. 30% ethanol extraction Crataegi fructus, Corni fructus and Mume fructus had antimicrobial effects on C. difficile without inhibiting the beneficial bacteria B. bifidum and L. plantarum. The MIC values of 30% ethanol extraction Crataegi fructus, Corni fructus and Mume fructus were found to be 10 mg/mL, 20 mg/mL and 5 mg/mL, respectively. Conclusions Crataegi fructus, Corni fructus and Mume fructus were identified as candidate medicines for C. difficile. Further researchs will need to be done in vivo, and to find an optimal extraction method accompanied by economic evaluation.

• Journal of Microbiology and Biotechnology
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• 제31권12호
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• pp.1624-1631
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• 2021

Prodigiosin as a high-valued compound, which is a microbial secondary metabolite, has the potential for antioxidant and anticancer effects. However, the large-scale production of functionally active Hahella chejuensis-derived prodigiosin by fermentation in a cost-effective manner has yet to be achieved. In the present study, we established carbon source-optimized medium conditions, as well as a procedure for producing prodigiosin by fermentation by culturing H. chejuensis using 10 L and 200 L bioreactors. Our results showed that prodigiosin productivity using 250 ml flasks was higher in the presence of glucose than other carbon sources, including mannose, sucrose, galactose, and fructose, and could be scaled up to 10 L and 200 L batches. Productivity in the glucose (2.5 g/l) culture while maintaining the medium at pH 6.89 during 10 days of cultivation in the 200 L bioreactor was measured and increased more than productivity in the basal culture medium in the absence of glucose. Prodigiosin production from 10 L and 200 L fermentation cultures of H. chejuensis was confirmed by high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) analyses for more accurate identification. Finally, the anticancer activity of crude extracted prodigiosin against human cancerous leukemia THP-1 cells was evaluated and confirmed at various concentrations. Conclusively, we demonstrate that culture conditions for H. chejuensis using a bioreactor with various parameters and ethanol-based extraction procedures were optimized to mass-produce the marine bacterium-derived high purity prodigiosin associated with anti-cancer activity.

• Journal of Microbiology and Biotechnology
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• 제32권7호
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• pp.877-884
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• 2022

Probiotics are microorganisms that can benefit host health when ingested in a live state, and lactic acid bacteria are the most common type. Among fungi, Saccharomyces boulardii (SB) is the only strain known to have a probiotic function with beneficial effects on colitis; however, information on other probiotic yeast strains is limited. Therefore, this study aimed to discover yeast strains expressing intestinal anti-inflammatory activities by exhibiting probiotic properties in dextran sodium sulfate (DSS)-induced colitis mice model. Nuruk (Korean traditional fermentation starter) containing various microbial strains was used as a source for yeast strains, and S. cerevisiae 28-7 (SC28-7) strain was selected with in vitro and in vivo characteristics to enable survival in the intestines. After 14 days of pretreatment with the yeast strains, DSS was co-administered for six days to induce colitis in mice. The results revealed that the disease activity index score was lowered by SC28-7 treatment compared to the DSS group, and the colon length and weight/length ratio were recovered in a pattern similar to that of the normal group. SC28-7 administration significantly reduced the secretion of pro-inflammatory cytokines in the serum and modified the mRNA expression of inflammatory cytokines (interleukin-1β, transforming growth factor-β, and interferon-γ) and proteins involved in gut barrier functions (mucin 2, mucin 3, zonula occludens-1, and occludin) in colon tissues. These results indicate that SC28-7 attenuates DSS-induced colon damage and inflammation, supporting its future use as a probiotic yeast for treating and preventing intestinal inflammatory diseases such as inflammatory bowel disease.