• 대한약침학회지
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• 제20권1호
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• pp.18-22
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• 2017

Objectives: The current investigation was carried out to determine the cytotoxic and the antimicrobial activities of methanolic extracts of Plumbago zeylanica. Methods: The stems, leaves, and whole plants were air dried and extracted with methanol by using a Soxhlet extractor for 72 hours at $55-60^{\circ}C$. The antimicrobial activities were determined from the zones of inhibition, which were measured by using the agar well diffusion method, and the cytotoxicity assays were performed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay method. Results: The methanolic extracts of the stem and the leaves of Plumbago zeylanica were tested against six bacterial species and nine fungal species, and both extracts showed antimicrobial activity in a dose-dependent manner. The leaf extract of Plumbago zeylanica showed maximum antimicrobial activity against both Staphylococcus aureus sub sp aureus and Fusarium oxysporum. The stem extract was found to be more antimicrobial against the Pseudomonas aeruginosa and the Penicillium expansum species. MTT assays were used to test the cytotoxicity of the whole plant extract in the HCT-116 and the K-562 cell lines, and that extract was shown to have weak cytotoxicity in both cell lines. Conclusion: In the present study, the methanolic stem extracts of Plumbago zeylanica were found to possess remarkable antibacterial activities against many human and agricultural pathogens. The extracts were also found to possess significant antifungal activities, but the antifungal activities were less than the antibacterial activities. Finally, the extracts were found to have weak cytotoxicities in the HCT-116 and the K-562 cell lines.

• Journal of Microbiology and Biotechnology
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• 제23권2호
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• pp.167-176
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• 2013

A novel bioactive molecule produced by Bacillus thuringiensis subsp. kurstaki Bn1 (Bt-Bn1), isolated from a common pest of hazelnut, Balaninus nucum L. (Coleoptera: Curculionidae), was determined, purified, and characterized in this study. The Bt-Bn1 strain was investigated for antibacterial activity with an agar spot assay and well diffusion assay against B. cereus, B. weinhenstephenensis, L. monocytogenes, P. savastanoi, P. syringae, P. lemoignei, and many other B. thuringiensis strains. The production of bioactive molecule was determined at the early logarithmic phase in the growth cycle of strain Bt-Bn1 and its production continued until the beginning of the stationary phase. The mode of action of this molecule displayed bacteriocidal or bacteriolytic effect depending on the concentration. The bioactive molecule was purified 78-fold from the bacteria supernatant with ammonium sulfate precipitation, dialysis, ultrafiltration, gel filtration chromatography, and HPLC, respectively. The molecular mass of this molecule was estimated via SDS-PAGE and confirmed by the ESI-TOFMS as 3,139 Da. The bioactive molecule was also determined to be a heat-stable, pH-stable (range 6-8), and proteinase K sensitive antibacterial peptide, similar to bacteriocins. Based on all characteristics determined in this study, the purified bacteriocin was named as thuricin Bn1 because of the similarities to the previously identified thuricin-like bacteriocin produced by the various B. thuringiensis strains. Plasmid elution studies showed that gene responsible for the production of thuricin Bn1 is located on the chromosome of Bt-Bn1. Therefore, it is a novel bacteriocin and the first recorded one produced by an insect originated bacterium. It has potential usage for the control of many different pathogenic and spoilage bacteria in the food industry, agriculture, and various other areas.

• Advances in Traditional Medicine
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• 제9권2호
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• pp.174-181
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• 2009

Pterocarpus marsupium, Clitoria ternatea, and Sanseveiria cylindrica are some of the important and endangered medicinal plant species of India. Despite of medicinal properties, antibacterial potential of the plants have not yet been explored. The present study was designed to optimize the in vitro technique for micropropagation and to screen the extracts from leaves and in vitro raised calli for antibacterial properties. Excised leaf-explants from the parent plants were surface sterilized and cultivated on Murashige & Skoog's (MS) medium containing $N^6$-benzyladenine (BA) in concentrations of 1, 2, 5, and $10{\mu}M$. Optimal growth of calli was noticed at a concentration of $5{\mu}M$, therefore the extracts from calli grown at this concentration were further studied for antibacterial activity. Both alcoholic and aqueous extracts from leaves of respective plants, and their in vitro raised calli were tested for antibacterial activity by agar well diffusion method against a range of Gram-positive and Gram-negative bacteria. Aqueous extracts showed antibacterial activity against limited number of bacterial species; notably the extracts of C. ternatea which showed antibacterial activity against Streptococcus pyogenes, Bacillus subtilis and Bacillus cereus. Alcoholic extracts of all three plants showed antibacterial activity against a wider range of bacteria. Among the Gram-positive bacteria, extracts from C. ternatea showed strong antibacterial activity against Bacillus spp., whereas the extracts of S. cylindrica showed good antibacterial potential for Staphylococcus aureus, S. epidermidis and S. pyogenes. The extracts from all three plants showed antibacterial activity against Gram-negative bacteria, including, Salmonella spp. and Shigella dysenteriae; organisms causing enteric fever and dysentery. In most of the cases, the extracts from respective calli showed comparable, and in some cases better, result in comparison to the extracts from parent leaves. To the best of our knowledge this is the first preliminary report on antibacterial potential, especially through calli extracts, of these plants; and in vitro cultivation of the explants may be used to obtain phytotherapeutic compounds.

• 대한약침학회지
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• 제19권3호
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• pp.246-252
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• 2016

Objectives: The purpose of this study was to obtain a natural antibiotic from Phenol-rich compounds; for the dressing and the treatment of chronic wounds. Methods: The Phenol-rich compound sweet gel was prepared by blending four natural herbal extracts, Acacia catechu (L.F.), Momia (Shilajit), Castanea sativa, and Ephedra sinica stapf, with combination of a sweet gel medium, including honey, maple saps, Phoenix dactylifera L. (date), pomegranate extract and Azadirachta indica gum as a stabilizer. The combinations were screened by using a well-diffusion assay with cloxacillin as a control. Pseudomonas spp. was tested with our novel antimicrobial compound. The zones of inhibition in agar culture were measured for each individual component and for the compound, and the results were compared with those of the control group which had been treated with cloxacillin. Data were expressed as means ${\pm}$ standard deviations. Quantitative analyses were performed using the paired t-test. Results: The antibiotic effect of the Phenol-rich compound sweet gel was statistically shown to be more significant than that of cloxacillin against Pseudomonas aeruginosa (P < 0.05). Conclusion: Our novel approach to fighting the antibiotic resistance of Pseudomonas proved to be successful. The Phenol-rich compound sweet gel was found to be suitable for use as an alternative medicine and bioactive dressing material, for the treatment of patients with various types of wounds, including burns, venous leg ulcers, ulcers of various etiologies, leg ulcers on the feet of diabetic, unhealed graft sampling sites, abscesses, boils, surgical wounds, necrotic process, post-operative and neonatal wound infection, and should be considered as an alternative to the usual methods of cure.

• Mycobiology
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• 제44권4호
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• pp.302-309
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• 2016

The role of lactic acid bacteria (LAB) in honey as antifungal activity has received little attention and their mechanism of inhibitory of fungi is not fully understood. In this study, LAB were isolated from honey samples from Malaysia, Libya, Saudi Arabia, and Yemen. Twenty-five isolates were confirmed LAB by catalase test and Gram staining, and were screened for antifungal activity. Four LAB showed inhibitory activity against Candida spp. using the dual agar overlay method. And they were identified as Lactobacillus plantarum HS isolated from Al-Seder honey, Lactobacillus curvatus HH isolated from Al-Hanon honey, Pediococcus acidilactici HC isolated from Tualang honey and Pediococcus pentosaceus HM isolated from Al-Maray honey by the 16S rDNA sequence. The growth of Candida glabrata ATCC 2001 was strongly inhibited (>15.0 mm) and (10~15 mm) by the isolates of L. curvatus HH and P. pentosaceus HM, respectively. The antifungal activity of the crude supernatant (cell free supernatant, CFS) was evaluated using well diffusion method. The CFS showed high antifungal activity against Candida spp. especially The CFS of L. curvatus HH was significantly (p < 0.05) inhibited growth of C. glabrata ATCC 2001, C. parapsilosis ATCC 2201, and C. tropicalis ATCC 750 with inhibitory zone 22.0, 15.6, and 14.7 mm, respectively. While CFS of P. pentosaceus HM was significantly (p < 0.05) effective against C. krusei, C. glabrata, and C. albicans with inhibition zone 17.2, 16.0, and 13.3 mm, respectively. The results indicated that LAB isolated from honey produced compounds which can be used to inhibit the growth of the pathogenic Candida species.

• 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.

• 한국식품과학회지
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• 제45권5호
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• pp.583-589
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• 2013

본 연구에서는 L. plantarum에 대한 항균성을 보이는 식물추출물들을 탐색한 후, 선별된 식물추출물들의 항균력을 실험실배지(MRSB)에서 규명하였다. 이후, 우수한 항균력을 보인 식물추출물들을 김치에 직접 적용하면서 김치의 발효지연 효과를 확인하였다. 식물추출물 2,117종을 대상으로 agar well diffusion assay를 수행한 결과, L. plantarum에 대한 항균성을 보이는 15종의 식물추출물들이 선별되었다. 선별된 15종의 식물추출물의 L. plantarum에 대한 최소저해농도를 확인한 결과, 자몽종자 추출물(0.0313 mg/mL), 소목열수추출물(0.2500 mg/mL), 오레가노 에센셜 오일(1.0 mg/mL)이 L. plantarum에 가장 우수한 항균력을 나타냈다. 이들 식물추출물들의 김치 발효조절 능력을 확인하기 위하여 자몽종자 추출물(0.1, 0.3, 그리고 0.5%), 소목추출물(0.1, 0.5, 그리고 1.0%), 오레가노 에센셜 오일(0.1, 0.5, 그리고 1.0%)을 개별적으로 김치에 첨가하여 $10^{\circ}C$에 20일간 저장하면서 김치의 pH 변화와 총균 및 젖산균의 개체수 변화를 확인하였다. 대조구의 pH는 저장 5일만에 적숙기에 도달한 반면, 자몽종자 추출물(0.1, 0.3, 그리고 0.5%), 소목추출물(0.1, 0.5, 그리고 1.0%), 그리고 오레가노 에센셜 오일(0.5와 1.0%)을 첨가한 김치는 적숙기에 도달하지 않았다. 이러한 현상은 총균과 젖산균의 개체수의 변화에서도 관찰되었다. 즉, 자몽종자 추출물(0.1, 0.3, 그리고 0.5%), 소목추출물(0.1, 0.5, 그리고 1.0%), 그리고 오레가노 에센셜 오일(0.5와 1.0%)을 첨가한 김치는 총균과 젖산균의 개체수가 식물추출물을 첨가하지 않은 김치와 비교하여 저장기간 동안 유의적으로 적었다. 본 연구의 결과는 L. plantarum에 대한 항균성을 보이는 식물추출물들에 대한 기본 정보를 제공하고, 자몽종자 추출물, 소목추출물, 오레가노 에센셜 오일을 김치에 직접 첨가함으로써 김치의 발효 속도를 지연시킬 수 있다는 것을 보여준다.

• 한국임상수의학회지
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• 제29권2호
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• pp.141-147
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• 2012

이 연구는 개의 귀 속에서 분리한 $Malassezia$ $pachydermatis$의 특성과 이들 효모에 대한 essential oil들의 항진균효과를 측정한 결과로서 일반적인 $M.$ $pachydermatis$를 분리하기위한 Sabouraud dextrose agar (SDA), olive oil이 첨가된 SDA (SDAO) 배지 및 지방 친화성 효모를 검출하기 위한 Leeming's medium (LM)으로 구성된 세종류의 분리배지가 사용되었다. $Malassezia$ spp는 77.8%의 개로부터 분리되었으며 분리배지에 따라 분리율에 큰 차이를 나타내었으며 지방성분이 포함된 배지에서의 분리율이 일반적으로 사용하는 SDA에서 보다 높았다. 분리된 모든 $Malassezia$ spp는 $M.$ $pachydermatis$로 동정되었지만 육안적으로 보이는 집락의 모양과 SDA에서의 증식속도를 고려했을 때 4개의 아종으로 관찰되었다. 배양 72시간 후 집락의 직경이 3 mm 이상인 큰 집락(LC)과 2 mm 정도인 중간 집락(MC) 및 배양 5일 후에도 1 mm 이상으로 크지지 않는 작은 집락(SC), 그리고 SDA에서 증식하지 않는 지방의존 집락(Lipo)으로 분류되었다. SDA, SDAO 및 LM 배지에서 각 type의 효모가 분리된 정도를 보면, LC type 효모는 각각 4, 11, 11개 시료에서, MC type 효모는 각각 2, 3, 1개 시료에서, SC type 효모는 각각 1, 2, 1개시료에서 분리되었으며 Lipo type은 SDAO과 LM 배지 중 3 곳에서 분리되었다. $M.$ $pachydermatis$에 대한 essential oil의 항진균효과 측정은 디스크 확산법과 well 확산법에 의해 이루어졌으며, 대부분의 essential oil은 0.5에서 1.0%의 농도에서 $M.$ $pachydermatis$ 의 증식을 억제하였다. MIC90과 MIC50은 essential oil의 성분에 따라 다양하였으나, Thyme oil이 가장 억제 효과가 좋았으며 marjoram과 tea tree oil은 비교적 낮은 억제 능력을 나타내었다.

• 한국어병학회지
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• 제30권2호
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• pp.89-96
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• 2017

현재 국내에 유통되고 있는 담수관상어의 대부분은 수입에 의존하므로 외래 병원체 및 항생제 내성균의 유입 가능성이 크다. 본 연구에서는 담수에 상재하는 균으로 인수공통 감염이 가능하며 어류에 조건성병원균으로 작용하는 Aeromonas hydrophila를 다양한 수입 담수관상어로부터 분리하여 특성을 분석하고자 하였다. 수입 후 1일 이내의 관상어를 수족관으로부터 수집하여 0.5% NaCl을 포함하는 TSA 배지에 간, 신장, 비장을 도말하여 세균을 분리하였다. 세균의 형태, 생화학적 특성 및 starch- ampicillin agar (SA)에서의 clear zone 형성 유무에 근거하여 분리 균의 약 70%인 226 균주가 Aeromonas spp.로 확인되어 이들의 분리 빈도가 매우 높음을 알 수 있었다. 이들 중 9균주를 선택하여 16S rRNA gene의 sequence를 분석한 결과 모두 A. hydrophila로 동정되었으며 API 20E test에서 대부분의 분리 균주는 amygdalin, D-melibiose, D-sucrose, trisodium citrate, L-arabinose 이용에서 표준 균주와 차이를 보였다. 10종의 항균제에 대한 분리 균주의 감수성을 디스크 확산법으로 확인한 결과 amoxycillin, ampicillin에 대해서는 모든 균주가 저항성이었고 florfecicol에 대해서는 모두 감수성이었다. 그러나 7균주는 tetracycline 계통의 항균제와 erythromycin, nalidixic acid 등에 복합내성을 보였다. A. hydrophila로 동정된 9개 분리 균주를 금붕어에 인위 감염을 실시한 결과, 3 균주는 5일 이내에 60~80%의 폐사를 나타내었다. 이러한 결과는 다약제내성이면서 독력이 있는 Aeromonas가 수입관 상어를 따라 국내로 유입되어 전파될 수 있으므로 수입상에서 소비처로 판매되기 전의 방어적 조치가 필요하다는 것을 시사한다.

• 대한임상검사과학회지
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• 제48권4호
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• pp.355-364
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• 2016

본 연구에서는 우리나라에 자생하는 약용 버섯인 마른진흙버섯의 자실체를 80%의 메탄올과 열수를 이용해 추출한 물질의 항산화와 항균 효과에 대한 실험을 수행하였다. 마른진흙버섯 자실체의 메탄올 추출물은 2.0 mg/mL 농도에서 DPPH 라디칼 소거능(93.65%)이 양성대조군인 BHT (96.97%)에 비해 낮았으나 상대적인 효과는 높았다. 철이온 소거능 실험에서 추출물의 모든 농도(0.125~2.0 mg/mL) 범위에서 철이온 소거능 항산화 효과가 BHT에 비해 월등하게 높은 것으로 나타났다. 또한 6종의 세균 S. aureus, S. mutans, B. subtilis, E. coli, P. aeruginosa, V. vulnificus와 1종의 곰팡이 C. albicans를 대상으로 200 mg/mL의 농도에서 메탄올 추출물을 이용해 agar well diffusion법으로 항균효과를 측정한 결과, V. vulnificus와 C. albicans를 제외한 5종의 세균에서 inhibition zone을 보여 메탄올 추출물은 여러 종류의 그람 양성세균과 그람 음성세균에 항균효과를 나타내는 것으로 나타났다. 또한 메탄올 추출물에 inhibition zone을 나타낸 S. aureus, S. mutans, B. subts, E. coli, P. aeruginosa 등 5종의 세균을 대상으로 최소저해농도 (MIC)를 측정한 결과 각각 100, 100, 50, 100, 200 mg/mL의 MIC를 나타내었다. 따라서 마른진흙버섯 자실체의 메탄올 추출물은 항산화 및 항균 효과가 높아서 이들 추출물은 천연 항산화제와 항균제로 이용이 가능할 것으로 사료된다.