• Journal of Microbiology and Biotechnology
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• 제13권3호
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• pp.429-436
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• 2003

Pediocin K1 is a bacteriocin produced by Pediococcus sp. KCA 1303-10, isolated from traditionally fermented flatfish in Korea. Pediocin K1-dependent antibiosis and pediocin K1-independent antibiosis against Listeria monocyrogenes were investigated by comparing antibiosis potential of the ped＋ wild-type strain of Pediococcus sp. KCA1303-10 with that of the ped- mutant strain in 3 different media at 3 different temperatures. In the synthetic MRS-APT medium, bacteriocin (pediocin K1)-dependent antibiosis (BDA) acted as the major driving force of overall antibiosis at the initial stage before the pH of the media was not sufficiently lowered, while bacteriocin-independent antibiosis (BIA) took over the major role at the late stage of antibiosis by killing otherwise resistant cells in the modium. The role of BDA increased as the temperature of the system decreased. The antibiosis potential of BDA among the overall antibiosis of Pediococcus against Listeria at $37^{\circ}C$ was calculated as 46%, and as 75% at $25^{\circ}C$. In the skim milk medium, antibiosis of Pediococcus against Listeria was weakened more than 4 log cycles compared to that of the synthetic medium; however, BDA worked as the main antibiosis force regardless of the culturing temperature in the skim milk medium. In the bean soup medium, BDA also worked as the major killing mechanism against Listeria, but BIA played as another suppressing mechanism against otherwise pediocin-resistant Listeria population. These results suggest that a large portion of the inhibitory action of the ped+Pediococcus sp. KCA1303-10 was attributable to the bacteriocin produced by the strain and that viable Pediococcus sp. KCA1303-10 was superior to the purified bacteriocin in suppressing the occurrence of the bacteriocin-resistant Listeria monocytogenes in food systems.

• 한국의류학회지
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• 제36권3호
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• pp.324-334
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• 2012

In this research, the dyeing properties of $Lycopus$ $lucidus$ Turcz on cotton and silk fabrics were evaluated to establish a scientific database of natural dyes. The optimum dyeing conditions were identified with K/S values depending on the dyeing concentration, temperature, time, and pH. For the optimum conditions, the color changes for different synthetic mordants were observed as L, $a^*$, $b^*$ and H, V, C. The color fastness after dyeing and mordanting was also examined. Additionally, the antibiosis of $Lycopus$ $lucidus$ Turcz was examined. The results were as follows: For the cotton, the optimized dyeing conditions were 300% (o.w.f.), $50^{\circ}C$, 40 min., and pH 5. For the silk fabric, the conditions were 450% (o.w.f.), $70^{\circ}C$, 60 min., and pH 4. The K/S value of dyed cotton improved about 1.03-2.78 folds after mordanting. The fabric color was yellow in the absence of mordanting, while it was reddish yellow after post-mordanting with FFC. Although the color changed with the mordanting method and mordant, the overall hue was yellow. Thus, $Lycopus$ $lucidus$ Turcz appears to have the potential for use as a natural dyeing material for a yellow hue. The K/S value of the dyed silk fabric improved about 1.05-1.40 folds after mordanting. The fabric showed a reddish yellow color when pre-mordanted with Al and Cu. The washing and dry-cleaning fastness of the cotton and silk fabrics were at the 4-5 level. The light fastness of the cotton improved after mordanting; however, pre-mordanting was more effective than post-mordanting or the absence of mordanting. The dyed cotton, silk fabrics showed excellent antibiosis.

• 한국미생물·생명공학회지
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• 제25권1호
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• pp.62-67
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• 1997

A potential biocontrol bacterium, YB-70 was isolated from a rhizosphere in suppressive soil and identified as a strain of Bacillus subtilis. In several biochemical and in vitro antibiosis tests on Fusarium solani with the culture filterates from B. subtilis YB-70, we found that antifungal mechanism of B. subtilis YB-70 was mediated by antibiotic substances produced from the bacterium. These antifungal substances were appeared to be hear-resistant, micromolecular, and ethy alcohol soluble. Antifungal agents produced by B. subtilis YB-70 showed strong inhibified against root-rotting fungi F. solani in in vivo pot test. An antifungal substance. YBS-1s, was purified from the culture broth of B. subtilis YB-70 by isoelectronic precipitation, silica gel column chromatography and Sephadex LH-20 column chromatography analysis by Fab-MASS, $^{1}$H-NMR, $^{13}$C-NMR, DEPT, and amino acid analyzer revealed that the YBS-1A was a peptide antibiotics of iturin class containing seven amino acids from five different groups, and the other(YBS-1B) was an analogue of iturin group composed of 11 amino acids with larher molecular weight of about 1, 500 dalton, which was lager than that of iturin A.

• Mycobiology
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• 제38권4호
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• pp.286-294
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• 2010

Epicoccum purpurascens stain 5615 AUMC was investigated for its biocontrol activity against root rot disease caused by Pythium irregulare. E. purpurascens greenhouse pathogenicity tests using three leguminous plants indicated that the fungus was nonpathogenic under the test conditions. The germination rate of the three species of legume seeds treated with a E. purpurascens homogenate increased significantly compared with the seeds infested with P. irregulare. No root rot symptoms were observed on seeds treated with E. purpurascens, and seedlings appeared more vigorous when compared with the non-treated control. A significant increase in seedling growth parameters (seedling length and fresh and dry weights) was observed in seedlings treated with E. purpurascens compared to pathogen-treated seedlings. Pre-treating the seeds with the bioagent fungus was more efficient for protecting seeds against the root rot disease caused by P. irregulare than waiting for disease dispersal before intervention. To determine whether E. purpurascens produced known anti-fungal compounds, an acetone extract of the fungus was analyzed by gas chromatography mass spectrometry. The extract revealed a high percentage of the cinnamic acid derivative (trimethylsiloxy) cinnamic acid methyl ester. The E. purpurascens isolate grew more rapidly than the P. irregulare pathogen in a dual culture on potato dextrose agar nutrient medium, although the two fungi grew similarly when cultured separately. This result may indicate antagonism via antibiosis or competition.

• 농약과학회지
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• 제13권4호
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• pp.275-282
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• 2009

선발된 PGPR 균주인 Bacillus subtilis C4와 Bacillus cereus D8 균주의 유채에 대한 생육촉진 및 무름병균인 Erwinia carotovora와 균핵병균인 Sclerotinia sclerotiorum에 대한 방제효과를 검정하기 위하여 실내검정과 온실검정을 실시하였다. 실내검정 결과, C4와 D8균주처리에 의하여 유채의 생육이 40.3%~74% 증가하였으며 무름병이 대조구에 비하여 80% 감소하였다. 실내검정에서 C4와 D8균주를 종자에 처리하였을 때 뿌리가 크게 신장되었다. 주요 식물병원균 Sclerotinia sclerotiorum, Rhizoctonia solani, Botrytis cinerea, Fusarium oxysporum, Phytophthora capsici, Colletotrichum acutatum에 대하여 항균활성시험을 수행한 결과 두 균주 중 C4균주는 모든 병원성 곰팡이에 대하여 항균활성을 나타내었다. 온실검정에서 C4와D8균주처리는 대조구에 비하여 유채의 초장, 엽폭 및 엽장을 19.5%~24.9%, 11.3%~15.3%, 14.1%~20.7% 각각 증가시켰으며 균핵병균인 Sclerotinia sclerotiorum에 대한 억제효과가 우수하였다. 이와 같은 결과를 볼 때 C4, D8 균주 처리는 유채의 생육을 촉진시키며 유채에 저항성을 유도하므로 친환경생물방제에 적용할 수 있을 것으로 생각된다.

• 한국축산식품학회지
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• 제31권5호
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• pp.741-747
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• 2011

예로부터 옷감의 염료 및 식용색소로 사용되어 온 치자는 혈당 저하, 항 종양, 항 혈전, 혈관신생 억제, 항산화, 항균 등 다양한 생리활성이 있는 것으로 보고되고 있으나 치자의 아질산염 소거 작용이나 육제품에의 이용에 관한 연구는 미비하다. 본 연구에서는 치자의 아질산염 대체 효과와 항균활성 등 기능성을 살펴보아 치자의 다양한 생리 기능성이 부여된 건강 지향적 육제품 개발의 기초자료로 활용하고자 아질산염(50, 100, 150 ppm)과 치자 추출물(0, 0.25, 0.5%)의 첨가량에 따른 돈육 패티의 물리 화학적 품질특성을 평가하고 아질산염 잔류량과 저장성을 살펴보았다. 패티의 색도를 측정한 결과 치자 추출물의 첨가에 따라 명도(CIE $L^*$)와 적색도(CIE $a^*$)가 감소되는 반면 황색도(CIE $b^*$)가 증가하였다. 돈육 패티를 가열한 결과 치자추출물이 첨가되지 않은 control 군에서는 아질산 첨가량이 많을수록 가열감량이 작았으나, 치자 추출물 첨가에 의한 가열감량의 변화는 명확히 관찰되지 않았다. $4^{\circ}C$에서 6주간 저장 후 패티의 pH, TBARS 및 VBN을 살펴본 결과 치자 추출물 첨가량이 많을수록 pH가 낮은 경향이었으나, TBARS와 VBN은 변화가 없었다. 돈육 패티의 아질산염 잔류량은 저장기간이 길어짐에 따라 점차 감소하였으며, 치자 추출물 첨가량이 많을수록 잔류량이 낮았다. 저장 중 미생물 오염을 살펴본 결과 대장균은 검출되지 않았으며, 일반세균은 치자 추출물 첨가에 따라 감소하여 항균 작용을 위한 아질산염 사용의 대체효과를 보였다. 이상의 결과를 보면 돈육 패티 제조 시 치자 추출물의 첨가는 아질산염 잔류량을 감소시킴과 함께 저장시 항균성을 증가시켜 건강 향상 기능성 천연 소재로서 치자의 이용 가능성을 시사한다.

• The Plant Pathology Journal
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• 제23권1호
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• pp.22-25
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• 2007

Biocontrol activity of five strains of selected rhizo-bacteria were tested in tomato against bacterial wilt caused by Ralstonia solanacearum. After root bacterization the plants were grown in a perlite-hydroponic system. Upon challenge inoculation with the pathogen, all of the rhizobacterial strains efficiently suppressed the bacterial wilt in tomato in various rates, at maximum by the strain, Bacillus vallismortis strain EXTN-1. While the percent of infected plants in the non-bacterized control plants were 95%, it was only 65% in plants pre-treated with EXTN-1. It was also demonstrated that the movement of R. solanacearum within the stem was significantly hampered when the plants were root bacterized. As EXTN-1 has no antagonistic properties against R. solanacearum, the bacterial wilt was probably suppressed by a mechanism other than antibiosis. Previously, the strain had been proven to produce an efficient elicitor for inducing systemic resistance in many crops. As the present study confirmed that EXTN-1 has the ability for reducing the pathogen spread in tomato, the strain could be effectively used as a potential biocontrol agent against bacterial wilt.

• Journal of Microbiology and Biotechnology
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• 제30권7호
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• pp.1027-1036
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• 2020

Stipa purpurea is a unique and dominant herbaceous plant species in the alpine steppe and meadows on the Qinghai-Tibet Plateau (QTP). In this work, we analyzed the composition and diversity of the culturable endophytic fungi in S. purpurea according to morphological and molecular identification. Then, we investigated the bioactivities of these fungi against plant pathogenic fungi and 1-aminocyclopropane-1-carboxylate deaminase (ACCD) deaminase activities. A total of 323 fungal isolates were first isolated from S. purpurea, and 33 fungal taxa were identified by internal transcribed spacer primers and grouped into Ascomycota. The diversity of endophytic fungi in S. purpurea was significantly higher in roots as compared to leaves. In addition, more than 40% of the endophytic fungi carried the gene encoding for the ACCD gene. The antibiosis assay demonstrated that 29, 35, 28, 37 and 34 isolates (43.9, 53.1, 42.4, 56.1, and 51.5%) were antagonistic to five plant pathogenic fungi, respectively. Our study provided the first assessment of the diversity of culture-depending endophytic fungi of S. purpurea, demonstrated the potential application of ACCD activity and antifungal activities with potential benefits to the host plant, and contributed to high biomass production and adaptation of S. purpurea to an adverse environment.

• 한국과학예술포럼
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• 제37권5호
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• pp.239-248
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• 2019

본 연구는 현재 목공예품 제작 시 사용성이 편하고 경제적이라는 이유로 합성 PVAc계 접착제가 주로 사용된다. 본 연구는 합성 PVAc계 접착제의 단점 중 작업자나 사용자에게 미치는 인체 안정성과 환경 유해성 등에 대한 문제점을 개선해보고자 하는 연구에서 시작되었다. 본 연구의 목적은 이러한 문제점이 대두되기 시작하면서 친환경에 대한 사회적 관심이 증대되고 수요도 급격히 증가되고 있는 상황으로 천연 접착제에 대한 연구를 통해 친환경 접착제를 개발하는 것이다. 따라서 본 논문은 목공예용 천연 접착제의 개발을 위해 천연 접착 소재인 셀룰로오스계 목재 추출물을 이용해 목공예용 천연 접착제를 개발하기 위한 기반 연구를 시도하였다. 연구결과 및 내용은 다음과 같다. 첫째, 목공예용 천연 접착제 개발을 위한 기반 물성인 접착 강도에서 기존 재료 보다 약 0.2 ~ 4 배 증진된 효과를 보여주었으며, 기존 재료와 유사하거나 안정적인 pH 값을 확인하였다. 또한 우수한 가역성을 나타내어 목공예용 접착제로서의 기초적인 물성은 확인되었으며, 자외선 열화에 대한 내구성도 약 1.5 ~ 8.5 배 우수한 결과값을 확인하였다. 이러한 연구결과를 바탕으로 셀룰로오스계 목재 추출물의 정제 기술 개발과 기능성 부여를 통한 접착강도, 항균성, 보존성 등에 대한 지속적인 연구가 이루어진다면 기존에 사용되어온 재료에 비해 성능이 개선된 목공예용 천연 접착제가 개발될 수 있을 것으로 기대한다.

• 농약과학회지
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• 제18권4호
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• pp.422-428
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• 2014

딸기 근권에서 분리한 내생균 중 고추역병균 방제 및 고추생육촉진 효과가 우수한 균주를 선발하였다. Pseudomonas fluorescen EP103으로 명명된 내생균주는 다른 내생균주와 비교하여 식물의 뿌리 길이와 생체 중이 크게 증가하였다. 고추역병에 대한 온실검정에서 EP103처리는 방제가 78.7%을 나타냈으며 항균력 실험결과 고추역병균을 직접 억제하지는 않았다. EP103이 처리된 고추에서는 PR1, PR10등의 병저항성 유전자가 발현되었으며 EP103의 PCR분석 결과 피올테오린, 파이로니트린, 하이드로젠 싸이아나이드, 오르화미드 등의 유용유전자를 함유하고 있음이 밝혀졌다. 따라서 본 균주는 고추역병의 생물 방제용으로 활용할 가치가 있는 것으로 판단된다.