• 미생물학회지
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• 제52권3호
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• pp.319-326
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• 2016

병원성 미생물들에 대해 항균활성을 보이는 $W5-1^T$ 균주가 한국의 발효식품인 김치에서 분리되었다. 이 분리주는 그람염색변이성, 절대호기성, 간균, 내생포자형성과 주모성의 편모를 가지고 운동성을 나타내었다. 균주는 $15-40^{\circ}C$, pH 6.0-10.0, 0-4% NaCl 조건에서 생육하였다. 균주는 esculin과 xylan을 가수분해하였고, $\small{D}$-mannose을 동화하였으나 $\small{D}$-mannitol은 동화하지 못하였다. $W5-1^T$ 균주는 Listeria monocytogens, Pseudomonas aeruginosa, Staphylococcus aureus, Salmonella typhi에 항균활성을 보였다. $W5-1^T$ 균주의 DNA의 G+C 함량은 52.6 mol%였다. 주요 호흡성 퀴논은 menaquinone-7 (MK-7)였고, 주요 세포성 지방산은 $C_{16:0}$, antieiso-$C_{15:0}$, $C_{18:0}$, and $C_{12:0}$였다. 균주는 세포벽 펩티도클리칸으로 meso-diaminopimelic acid을 함유하였다. 16S rRNA 유전자서열 분석에 근거하여 $W5-1^T$ 균주는 Paenibacillaceae 과로 분류되었으며 Paenibacillus pinihumi $S23^T$(98.4% similarity), P. tarimensis $SA-7-6^T$(96.4%) 균주와 높은 연관성을 보였다. 분리주와 P. pinihumi $S23^T$는 8.5%의 DNA-DNA 관련성을 보임으로 $W5-1^T$ 균주가 Paenibacillus 속의 한 종임을 보여주었다. 이러한 다각적 연구의 증거로 볼 때 $W5-1^T$ 균주는 Paenibacillus 속의 신종으로 사료되어 Paenibacillus kimchicus로 명명을 제안하며, 표준균주는 $W5-1^T$(=KACC $15046^T$=LMG $25970^T$)이다.

• 대한영양사협회학술지
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• 제24권4호
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• pp.330-343
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• 2018

Recently, there has been a growing demand for natural preservatives because of increased consumer interest in health. In this study, we produced Lactobacillus rhamnosus cell-free supernatant (LCFS) and evaluated and compared its antimicrobial activity with existing natural preservatives against pathogenic microorganisms and in chicken breast meat contaminated with Escherichia coli and Staphylococcus aureus. Lactobacillus rhamnosus cell-free supernatant possessed 30 units of lysozyme activity and contained 18,835 mg/L of lactic acid, 2,051 mg/L of citric acid and 5,060 mg/L of acetic acid. Additionally, LCFS inhibited the growth of fourteen pathogenic bacteria, S. aureus, Bacillus cereus, Listeria monocytogenes, Vibrio parahaemolyticus, Listeria innocua, S. epidermidis, L. ivanovii, E. coli, Pseudomonas aeruginosa, Shigella sonnei, Shi. flexneri, Proteus vulgaris, Pseudomonas fluorescens, and Klebsiella pneumoniae. The antibacterial activity of LCFS was stronger than that of egg white lysozyme (EWL), Durafresh (DF) and grapefruit seed extract (GSE). Additionally, LCFS maintained its antimicrobial activity after heat treatment at $50^{\circ}C{\sim}95^{\circ}C$ and at pH values of 3~9. Moreover, LCFS inhibited the growth of E. coli and S. aureus in chicken breast meat. In conclusion, it is expected that LCFS, which contains both lysozyme and three organic acids, will be useful as a good natural preservative in the food industry.

• Journal of Microbiology and Biotechnology
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• 제28권5호
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• pp.697-706
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• 2018

Lactobacillus pentosus K1-23 was selected from among 25 lactic acid bacterial strains owing to its high inhibitory activity against several pathogenic bacteria, including Escherichia coli, Salmonella typhimurium, S. gallinarum, Staphylococcus aureus, Pseudomonas aeruginosa, Clostridium perfringens, and Listeria monocytogenes. Additionally, among 13 strains of Aureobasidium spp., A. pullulans NRRL 58012 was shown to produce the highest amount of ${\beta}$-glucan ($15.45{\pm}0.07%$) and was selected. Next, the optimal conditions for a solid-phase mixed culture with these two different microorganisms (one bacterium and one yeast) were determined. The optimal inoculum sizes for L. pentosus and A. pullulans were 1% and 5%, respectively. The appropriate inoculation time for L. pentosus K1-23 was 3 days after the inoculation of A. pullulans to initiate fermentation. The addition of 0.5% corn steep powder and 0.1% $FeSO_4$ to the basal medium resulted in the increased production of lactic acid bacterial cells and ${\beta}$-glucan. The following optimal conditions for solid-phase mixed culture were also statistically determined by using the response surface method: $37.84^{\circ}C$, pH 5.25, moisture content of 60.82%, and culture time of 6.08 days for L. pentosus; and $24.11^{\circ}C$, pH 5.65, moisture content of 60.08%, and culture time of 5.71 days for A. pullulans. Using the predicted optimal conditions, the experimental production values of L. pentosus cells and ${\beta}$-glucan were $3.15{\pm}0.10{\times}10^8CFU/g$ and $13.41{\pm}0.04%$, respectively. This mixed culture may function as a highly efficient antibiotic substitute based on the combined action of its anti-pathogenic bacterial and immune-enhancing activities.

• Advances in environmental research
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• 제7권2호
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• pp.73-85
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• 2018

The anaerobically digestion and agricultural application of organic wastes was conducted using food wastes and cow dung. Twenty kilograms each of the feed stocks was added into two 30 liters-capacity batch digesters. The anaerobic digestion was carried out within a temperature range of $25-31^{\circ}C$ for a retention time of 51 days. The results showed a cumulative gas yield of 5.0 bars for food waste and no gas production for cow dung within the retention time. Bacteria such as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Proteus vulgaris and Clostridium sp were isolated. Fungi isolated included Aspergillus niger, Aspergillus nidulan, Trichophyton rubrum and Epidermophyton flocossum. The non-dispersive infrared (NDIR) analysis of the biogas produced confirmed that the gas consisted of $CH_4$, $CO_2$ and $H_2$. Statistical analysis revealed there was no significant correlation between temperature and biogas produced from the organic wastes (r= 0.177, p = 0.483).The organic wastes from the biogas production process stimulated maize growth when compared to control (soil without organic waste) and indicated maximum height. The study therefore reveals that food waste as potential substrates for biogas production has a moderate bio-fertilizer potential for improving plant growth and yield when added to soil.

• Journal of Microbiology and Biotechnology
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• 제23권9호
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• pp.1229-1243
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• 2013

In this paper, an air isolate (NITT6L) has been screened based on hemolytic activity, emulsification activity, drop collapsing test, and oil displacement test, as well as lipase activity. It was found that strain NITT6L was able to reduce the surface tension of the medium from 61.5 to 39.83 mN/m and could form stable emulsions with tested vegetable oils. Morphological, biochemical, 16S rRNA sequencing analyses, and fatty acid methyl ester analysis using gas chromatography confirmed that the air isolate under study was Pseudomonas aeruginosa. Characterization of the biosurfactant using agar double diffusion assay revealed that the biosurfactant was anionic in nature, and CTAB-methylene blue assay and Molisch test revealed its glycolipid nature. The FT-IR spectrum confirmed that the crude biosurfactant was a rhamnolipid. Using unoptimized medium containing sucrose as the carbon source, the isolate was found to produce 0.3 mg/ml of rhamnolipid in batch cultivation (shake flask) at $37^{\circ}C$ and pH 7. Optimization of the medium components was carried out using design of experiments and the yield of rhamnolipid has been enhanced to 4.6 mg/ml in 72 h of fermentation.

• International Journal of Industrial Entomology and Biomaterials
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• 제17권2호
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• pp.223-228
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• 2008

A novel beetle antimicrobial protein from stimulated Copris tripartitus and the corresponding gene were isolated in parallel through differential display-PCR and expression in Escherichia coli. To find cDNA clones responsible for bacteria resistance, the suppression subtractive hybridization and GeneFishing differentially expressed genes system were employed in the dung beetle, Copris tripartitus immunized with lipopolysaccaride. One cDNA clone from eight subtracted clones was selected through dot blot analysis and confirmed by northern blot analysis. The 516-bp, selected cDNA clone was determined by 5' and 3' rapid amplication of cDNA ends and cloned into the GST fusion expression vector pGEX-4T-1 for expression of the protein. The expressed protein was predicted 14.7 kDa and inhibited the growth of gram-negative bacteria such as Escherichia coli and Pseudomonas aeruginosa. These results implied that the expressed protein is related to immune defense mechanism against microorganism.

• The Plant Pathology Journal
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• 제16권5호
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• pp.286-289
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• 2000

Mechanol extracts of three cold-tolerant eucalyptus trees-Eucalyptus darlympleana, E. gunnii and E. unigera were screened for antimicrobial activity against twenty two phyto-pathogenic fungi and six food-borne bacterial pathogens. E. unigera showed the antagonistic activity against all the tested pathogens. Among the tested fungal pathogens, Pythium species were highly sensitive to the leaf extracts. Especially, P. vanterpoolii, a causal agent of leaf blight in creeping bentgrass (Agrostis palustris), was completely inhibited by the extracts. The eucalyptus extracts were also effective in inhibiting the fungal growth of Botrytis cinerea and Phomopsis sp. isolated from the lesions of kiwifruit soft rot during post-harvest storage. Escherichia coli O-157 was less sensitive to the inhibition than the other bacterial pathogens tested. It was likely that Gram positive bacteria-Bacillus subtilis and Streptococcus mutans were more sensitive to the eucalyptus extracts than Gram negative bacteria-Escherichia coli, Salmonella enteritidis and Pseudomonas aeruginosa. Our findings suggest that the cold-tolerant eucalyptus species have antimicrobial properties that can serve the development of novel fungitoxic agents or food preservatives.

• 한국식생활문화학회지
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• 제22권2호
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• pp.266-273
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• 2007

차조기의 30, 50, 70, 95% 에탄올 추출물과 물추출물의 식품 관련 미생물에 대한 항균 활성과 이들 추출물의 분획물에 대한 항균 활성을 살펴보았다. 본 실험에 사용한 차조기의 무기질은 Ca와 Mg 함량이 각각 595.75 mg%와 467.0 mg%으로 가장 많았다. 에탄올 혼합 추출물과 물추출물의 추출 수율은 에탄올 농도가 낮을수록 증가하여 95%에탄올 추출물은 9.3%, 70% 추출물은 16.5%, 50% 추출물은 18.9%, 30% 추출물은 19.4%, 물추출물(0%)에서는 20.8%이었다. 추출용매의 에탄올 농도가 낮아질수록 hexane 층으로 용출되어 나오는 성분은 감소하고 ethyl acetate 층 분획성분은 점차 증가하는 것으로 나타났다. 에탄올 추출물과 물 추출물의 항균력은 95%, 70%와 50% 에탄올 추출물이 Staphylococcus aureus, Bacillus subtilis 및 Pseudomonas areuginosa에 대하여 clear zone을 나타내었다. 추출물을 단계별 계통 분획하여 얻은 분획물의 항균력 실험에서는 ethyl acetate층이 실험 대상 미생물 모두에 대하여 항균 활성을 나타내었으며 에탄올 혼합율이 낮을수록 즉, 30% 에탄올과 물추출물의 ethyl acetate분획물의 저해환이 가장 크게 나타났다. 물 추출물의 ethyl acetate 분획물을 첨가한 액체배양에서 500 ppm의 농도에서는 S. aureus, B. subtilis와 P. aeruginosa에 대하여 대조구의 뚜렷한 증가와 대조적으로 낮은 생균수를 보였으며, 1,000 ppm의 농도에서는 실험 균주 모두에 대하여 배양 24시간 내내 생육이 저해되는 것으로 나타났다. 물 추출과 에탄올 추출의 농도와 항균 활성, 폴리페놀 함량 및 플라보노이드 함량이 비례적인 상관관계에 있는 것으로 나타나지는 않으나 30% 에탄올 추출물과 물 추출물의 ethyl acetate분획물이 폴리페놀 함량이 높고 항균력이 가장 강한 것으로 나타났다.

• 약학회지
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• 제40권4호
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• pp.428-437
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• 1996

The in vitro and in vivo antibacterial activities of a new fluoroquinolone, DWP20364(1-cyclopropyl-5-amino-6,8-difluoro-7-(2,7-diazabicyclo[3.3.0]oto-4-ene-7-yl)-1 ,4-di-hydro-4-oxoquinoline-3-carboxylic acid) were evaluated in comparison with those of ciprofloxacin(CPFX), sparfloxacin(SPFX) and ofloxacin(OFLX). DWP20364 was more potent than CPFX and OFLX against Staphylococcus spp., Streptococcus spp. and Enterococcus faecium MD8b and it was similarly or slightly less active than CPFX against Escherichia spp. and Pseudomonas spp.. For MRSA and OFLX resistant strains (Staphylococcus spp.(14),Enterococcus spp.(4), Acinetobacter spp.(2), Pseudomonas spp.(9), Klebsiella spp.(2) and Serratia spp.(6)),DWP20364(MICs for 90% of strains,0.025 and 12.5${\mu}$g/ml, respectively) was 4 to 32 folds more potent than SPFX and CPFX. The activity of DWP20364 decreased moderately in the presence of 5mM $Mg^{2+}$. However, various pHs and the concentrations of various serum had no effect on the activity of DWP20364. DWP20364 possessed a bacteriocidal effect at the 1MIC against gram positive and gram negative strains. The protective effect of DWP20364 against systemic infections in mice caused by S. aureus Smith or S. aureus L2379 was superior to that of CPFX and SPFX but it was less active than that of CPFX against infection by P. aeruginosa E-2.

• Archives of Pharmacal Research
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• 제21권5호
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• pp.570-575
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• 1998

To develop a cotton derivatives with prolonged antimicrobial activities, homosulfamine (Hs) was coupled to cotton xanthate (CX) via chelate bond in the presence of Cu(II) ion by one- and two-bath processes. In one-bath process, CX was treated with Cu(II)-Hs solution. In two-bath process, CX was treated with Cu(II) ion solution to produce CX-Cu(II) complex, which was isolated and treated in turn with Hs solution. Effects of concentration, Cu(II)/Hs ratio, and pH on the binding of Hs were investigated at $10{\circ}C$ . In one-bath process, binding of hs took place readily with optimum pH around 5-6. the amount of binding increased to give a maximum within 5 min and decreased slowly to establish an equilibrium withhin an hour. In two-bath process, binding of Hs was much lower than that of one-bath process. Release of Hs from CX-Cu(II)-Hs was investigated by batch and flow method. antimicrobial activiteis of CX-Cu(II)-Hs was investigated by batch and flow method. Antimicrobial activities of CX-Cu(II)-Hs were tested against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa and Escherichia coli and it showed prolonged activity compared to that of free Hs.