• Mycobiology
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• 제44권4호
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• pp.338-342
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• 2016

The culture filtrate of Lentinula edodes shows potent antimicrobial activity against the plant pathogenic bacteria Ralstonia solanacearum. Bioassay-guided fractionation was conducted using Diaion HP-20 column chromatography, and the insoluble active compound was not adsorbed on the resin. Further fractionation by high-performance liquid chromatography (HPLC) suggested that the active compounds were organic acids. Nine organic acids were detected in the culture filtrate of L. edodes; oxalic acid was the major component and exhibited antibacterial activity against nine different phytopathogenic bacteria. Quantitative analysis by HPLC revealed that the content of oxalic acid was higher in the water extract from spent mushroom substrate than in liquid culture. This suggests that the water extract of spent L. edodes substrate is an eco-friendly control agent for plant diseases.

• Journal of Microbiology and Biotechnology
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• 제24권2호
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• pp.160-167
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• 2014

Oligopeptidase B (OpdB) is a serine peptidase widespread among bacteria and protozoa that has emerged as a virulence factor despite its function has not yet been precisely established. By using an OpdB-overexpressing Escherichia coli strain, we found that the overexpressed peptidase makes the bacterial cells specifically less susceptible to several proline-rich antimicrobial peptides known to penetrate into the bacterial cytosol, and that its level of activity directly correlates with the degree of resistance. We established that E. coli OpdB can efficiently hydrolyze in vitro cationic antimicrobial peptides up to 30 residues in length, even though they contained several prolines, shortening them to inactive fragments. Two consecutive basic residues are a preferred cleavage site for the peptidase. In the case of a single basic residue, there is no cleavage if proline residues are present in the $P_1$ and $P_2$ positions. These results also indicate that cytosolic peptidases may cause resistance to antimicrobial peptides that have an intracellular mechanism of action, such as the proline-rich peptides, and may contribute to define the substrate specificity of the E. coli OpdB.

• Journal of Pharmaceutical Investigation
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• 제12권1호
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• pp.1-11
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• 1982

Silver sulfadiazine has been introduced to replace silver nitrate in the topical treatment of extensive burns and this drug exerts a prominent antibacterial action against Pseudomonas aeruginosa. The compound is painless upon application and insufficient sulfadiazine is absorbed to cause crystalluria. The primary purpose of the study was to clarify the antimicrobial action of zinc sulfadiazine ointment in comparison with silver sulfadiazine ointment as well as the pharmaceutical properties of the zinc sulfadiazine preparations. The results are summerized as followings: 1) The optimum ratio of two substrate compounds for the synthesis of zinc sulfadiazine are 2 moles of sulfadiazine and 1 mole of zinc sulfate at pH 6.0. 2) The stability of zinc sulfadiazine ointment preparation by using polyethylene glycol base, Beeler's base or polyoxyl 40 stearate base was more stable than that of silver sulfadiazine preparations. 3) The antimicrobial action of zinc sulfadiazine exhibits a stronger antimicrobial activity than that of sulfadiazine against Staphylococcus aureus but the opposite is true against Pseudomonas aeruginosa.

• 한국식품영양과학회지
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• 제30권5호
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• pp.964-968
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• 2001

향균력이 있는 한약제들 중에서 추출수율과 항균력이 우수한 항금을 대상으로 식중독균에 대한 천연항균제의 적용 가능성을 검토하였다. 황금추출물의 항균작용을 알아보기 위하여 공시균주 Bacillus cereus, Listeria monocytogenes, Escherichia coli, and Vivro parahaemolyticus에 대하여 disk method에 의한 항균력 검사에서 생육어제로 인한 clear zone 이 선명하게 관찰되어 황금추출물의 항균력을 알 수 있었고, 황금추출물의 열 및 PH 안정성을 검토한 결과 다양한 범위의 온도 및 pH에 대해서 매우 안정하다는것을 확인하였으며, 공시균주들에 대한 유효저해농도를 측정한 결과 황금추출물의 농도 500 ppm 이상에서 생육이 억제되었다. 주사형전자현미경(SEM) 상에서는 처리구에서 공시균주들의 세포형태 변화를 볼수 있었고, 투과형전자현미경(TEM)상에서는 처리구에 있어서 공시균주들의 세포막 파괴로 인하여 세포내용물이 용출된 것을 볼 수 있었다. 황금추출물 처리로 인한 세포막 손상정도를 확인하기 위하여 균체내 효소인 $\beta$-gal-actosidase 활성을 정량한 결과 chlorogorm 보다 세포막을 더 손상시키는 것을 확인되었다.

• 한국진공학회지
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• 제6권S1호
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• pp.27-33
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• 1997

Recently ion beam assistant deposition (IBAD) was successfully used to produce a dense ultra-adherent and pinhole-free hydroxyapatite (HAp) layer on alumina substrate. After that the HAp-coated alumina was immersed in 20ppm and 100ppm $AgNO_3$ solution at room temperature for 48 hours to carry out the ions exchange between $Ag^+\;and\;Ca^+$ in HAp. The obvious antimicrobial effect against E.Coli, P. Aeruginosa and S. Epidermidis was observed in the samples treated with 20ppm $AgNO_3$ Solution, In contrast to this the untreated samples did not show any bactericidal effect. Scanning electron microscope(SEM) study showed that Ag homogeneously distributed on the surface. X-ray diffraction (XRD) demonstrated that the surface structure in the samples without Ag was HAp whereas with Ag is HAp and AgCaP. It appears that silver ions exchange with calcium ions in HAp does not cause significant changes in the structure of HAp coatings.

• Mycobiology
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• 제43권3호
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• pp.311-318
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• 2015

Culture filtrates of six different edible mushroom species were screened for antimicrobial activity against tomato wilt bacteria Ralstonia solanacearum B3. Hericium erinaceus, Lentinula edodes (Sanjo 701), Grifola frondosa, and Hypsizygus marmoreus showed antibacterial activity against the bacteria. Water, n-butanol, and ethyl acetate extracts of spent mushroom substrate (SMS) of H. erinaceus exhibited high antibacterial activity against different phytopathogenic bacteria: Pectobacterium carotovorum subsp. carotovorum, Agrobacterium tumefaciens, R. solanacearum, Xanthomonas oryzae pv. oryzae, X. campestris pv. campestris, X. axonopodis pv. vesicatoria, X. axonopodis pv. citiri, and X. axonopodis pv. glycine. Quantitative real-time PCR revealed that water extracts of SMS (WESMS) of H. erinaceus induced expressions of plant defense genes encoding ${\beta}$-1,3-glucanase (GluA) and pathogenesis-related protein-1a (PR-1a), associated with systemic acquired resistance. Furthermore, WESMS also suppressed tomato wilt disease caused by R. solanacearum by 85% in seedlings and promoted growth (height, leaf number, and fresh weight of the root and shoot) of tomato plants. These findings suggest the WESMS of H. erinaceus has the potential to suppress bacterial wilt disease of tomato through multiple effects including antibacterial activity, plant growth promotion, and defense gene induction.

• 한국식품영양과학회지
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• 제43권4호
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• pp.577-583
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• 2014

누룩군과 입국군을 달리 첨가하여 제조한 막걸리의 발효 중의 이화학적 특성과 항균활성을 조사하였고 발효 과정 중 항균활성이 있는 미생물을 동정하였다. 발효 3일째 pH 결과는 누룩군이 입국군에 비해서 낮았다. 그러나 산도와 알코올의 함량은 발효 15일째에서 누룩군이 입국군에 비해서 유의적으로 높았다. 총당과 총균수는 입국으로 만든 막걸리가 누룩으로 만든 막걸리보다 더 높게 나타났다. 관능검사 평가 결과, 색, 단맛, 향, 목넘김, 전반적 기호도는 입국군(DKB)이 가장 우수하게 나타났다. 항균활성 결과 누룩 샘플 GND, ANF에서 Salmonella enterica, Bacillus subtilis, Escherichia coli, Bacillus cereus에서 항균력이 나타난 미생물을 동정하였다. 균주 ST-1은 GND에서 분리하여 16S rRNA 염기서열에 기초하여 동정한 결과 Paenibacillus polymyxa strain RCP6과 99%의 상동성을 보였다. 따라서 P. polymyxa ST-1은 항진균활성과 항세균활성을 가진 bacteriocin-like substances를 생산함을 알 수 있고 이와 같은 새로운 항미생물 물질은 천연식품보존제 및 사료보존제뿐만 아니라 항생제 대체 의약품으로도 활용이 기대되며, 이를 위하여 향후 이 물질들의 보다 정확한 구조 및 특성을 규명하는 연구가 필요하다.

• Applied Biological Chemistry
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• 제37권6호
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• pp.456-462
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• 1994

라이소자임-덱스트란 hybrids는 상대 습도 80%와 $60^{\circ}C$에서 16일간 유지시켜 만들었다. 라이소자임-덱스트란 hybrids의 유화성은 라이소자임보다 약 14배 정도, 시판유화제보다는 약3배 정도 높았다. 그 hybrids의 효소 활성도는 기질로 Micrococcus lysodeiticus 세포벽을 사용한 결과 라이소자임의 약 83% 정도였다. 그 hybrids의 뛰어난 유화성은 pH 3에서도 유지되었고 pH 10에서는 더욱 개선되었다. $100^{\circ}C$로 가열 처리함으로써 유화성은 크게 향상되었다. 또한 라이소자임-덱스트란 hybrids 이 그람음성세균에 대하여 항균효과를 나타냈다. 이 결과들은 라이소자임-덱스트란 hybrids가 식품에서 보존료와 유화제로 사용될 수 있다고 사료된다.

• Journal of Electrochemical Science and Technology
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• 제14권1호
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• pp.15-20
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• 2023

Ionic liquids are considered as a promising, alternative solvent for the electrochemical synthesis of metals because of their high thermal and chemical stability, relatively high ionic conductivity, and wide electrochemical window. In particular, their wide electrochemical window enables the electrodeposition of metals without any side reaction of electrolytes such as hydrogen evolution. The electrodeposition of silver is conducted in 1-n-butyl-3-methylimidazolium chloride ([C4mim]Cl) ionic liquid system with a silver source of AgCl. This study is the first attempt to electrodeposit silver nanoparticles without using co-solvents other than [C4mim]Cl. Pulse electrolysis is employed for the synthesis of silver nanoparticles by varying applied potentials from -3.0 V to -4.5 V (vs. Pt-quasi reference electrode) and pulse duration from 0.1 s to 0.7 s. Accordingly, the silver nanoparticles whose size ranges from 15 nm to ~100 nm are obtained. The successful preparation of silver nanoparticles is demonstrated regardless of the kinds of substrate including aluminum, stainless steel, and carbon paper in the pulse electrolysis. Finally, the antimicrobial property of electrodeposited silver nanoparticles is confirmed by an antimicrobial test using Staphylococcus aureus.

• 생명과학회지
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• 제12권6호
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• pp.803-811
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• 2002

초석잠 헥산 추출물이 식중독균에 대한 천연 항균 활성 가능성을 검토하였다. 초석잠 헥산 추출물의 항균 작용을 알아보기 위하여 공시 균주인 Bacillus cereus, Staphylococcus aureus, E, coli 및 Listeria monocytogenes등에 대하여 disc법으로 실험한 결과 그람음성 및 그람 양성균에 대하여 15~20 mm의 clear zone이 나타났다. 초석잠 헥산 추출물의 MIC는 Bacillus cereus에 대해 250${\mu}g$/$m\ell$ Listeria monocytogenes에 대해 250~500/$m\ell$그리고 Staphylococcus aureua와 Pseudomonoas aeruginosa에 대해 각각 500${\mu}g$/$m\ell$ 나타내었다. 초석잠 추출물을 처리한 전자현미경(TEM)상에서는 처리균주들의 세포막이 파괴되어 세포내용물이 용출된 것을 볼 수 있었다. 초석잠 추출물을 처리한 균주의 세포막 손상의 정도를 알아보기 위하여 균체내 효소인 $\beta$-galactosidase 활성을 측정한 결과 클로로포름보다 세포막을 더 손상시키는 것이 확인되었다. 그리고 초석잠 추출물의 pH 및 열 안정성을 실험한 결과 매우 안정하였다.