• The Plant Pathology Journal
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• 제20권4호
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• pp.271-276
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• 2004

To examine the control effect of damping-off on radish caused by Pythium spp., researchers used the isolates of a fungivorous nematode, Aphelenchus avenae, and antagonistic fungi, Trichoderma spp. These were used as biocontrol agents, either alone, or in combination. Growth rates of the A. avenae isolates and fungal damages by the nematodes varied depending on Trichoderma spp., which contained lower T. koningii and T. virens cultures than other Trichoderma cultures. Phythium spp. were damaged by all five Aphelenchus isolates, but the multiplication rate of nematode isolate Aa-3 was very poor. Antibiotic activity of T. virens and T. harzianum to Pythium spp. was stronger than that of T. koningii. Control efficacy against damping-off of radish was most enhanced under the treatment using the nematode-T. harzianum combination. On the contrary, the combinations of the nematodes and T. virens or T. koningii mostly did not increase or decreased their control effect vis-$\`{a}$-vis that of the nematodes or antagonistic fungi being used alone. The results suggest that the fungivorous nematodes may play a leading role in the disease control, and that the activity of the fungivorous nematodes may be activated by T. harzianum, but inhibited by T. koningii and T.virens.

• 한국조리학회지
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• 제9권4호
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• pp.113-122
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• 2003

유용미생물을 이용한 콩나물 부패 원인균에 대한 길항작용과 콩나물 생육에 미치는 영향에 대한 연구의 일환으로 Pseudomonas areofacience 14H-3, Pseudomouas fluorescens Rl-12, Bacillus cereus Yell균을 이용하여 콩나물 부패 원인균에 대하여 길항능력과 콩나물 생육에 미치는 영향에 대하여 조사한 결과는 다음과 같다. P. areofacience 14H-3균주와 B. cereus Yell 균주는 Rizoctonia solani에 높은 길항력을 보였으며, P. areofacience 14H-3과 B. cereus Yell은 세균병에 특히 높은 항균력을 나타내었다. 길항세균의 배양여액을 PDA에 첨가하여 콩나물 부패균의 증식 억제 효과를 조사한 결과 P. areofacience 14H-3과 P. fluorescens Rl-12은 78.8% 억제율을 보였으며 B. cereus. Yell은 52.9%의 억제율을 보였다. 길항미생물과 배양여액을 처리하여 콩나물을 재배한 결과 B. cereus Yell 처리구가 대조구에 비해 콩나물의 총무게가 증가하는 것으로 나타났다. 길항세균 배양여액에 콩을 침지하여 재배한 결과 200배액 처리구가 대조구에 비해 생육이 양호하였다. 콩나물의 일반성분을 분석한 결과 수분, 회분, 총당에서는 유의적인 차이가 나타나지 않았으나, 조단백의 경우 B. cereus Yell(8.9%)가 control(3.6%)보다 약 2배 정도 증가하였으며, 조지방과 조섬유의 경우는 P. areofacience 14H-3, P. fluorescens Rl-12가 control보다 각각 2배 정도 함량이 증가하였다. 비타민의 경우도 대조구(9.9mg%)에 비하여 길항미생물 처리구(9.4∼10.8mg%)가 높게 나타났다.

• 생명과학회지
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• 제20권8호
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• pp.1254-1260
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• 2010

식물 근권미생물은 식물의 뿌리 표면과 내부에 정착하면서 식물생장 촉진물질을 분비하여 식물생육에 직접적인 영향을 주거나, 항균물질을 분비하여 병원균으로부터 식물 근권환경을 보호하여 식물의 생육을 촉진하게 된다. 이러한 활성을 갖고 있는 미생물을 분리하여 동정하며, 항균물질을 분리, 동정하여 지속농업의 발전과 농업환경의 보전을 위하여 연구를 실시하였다. 논토양으로부터 식물생육촉진활성과 항균활성을 갖는 RRj 228균주를 분리하여, 생리 생화학적방법과 유전학적 방법으로 동정한 결과, Pseudomonas sp.로 동정되었다. RRj 228균주는 B. cinerea, P. ultimum, P. capsici와 R. solani에도 높은 항균활성을 보였으며, 특히 고추탄저병원균인 C. acutatum에 강력한 항균활성을 나타냈다. RRj 228균의 배양여액을 C. acutatum, R. solani 및 P. ultimum에 대한 $ED_{50}$값을 측정한 결과 0.14, 0.16, 0.29 mg/ml로 나타났다. 항균활성물질은 RRj 228 배양여액으로부터 각종 크로마토그라피법으로 순수분리하고, NMR과 GC/MS 등의 기기분석을 실시하여 구조를 Phenazine-1-carboxylic acid (분자량 224)로 동정하였다.

• 생명과학회지
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• 제13권6호
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• pp.843-848
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• 2003

가금티프스는 가금류에 Salmonella gallinarum이 원인균이 되어 발병하는 양계산업에 막대한 지장을 주는 질병이다. 가금티프스를 억제하기 위한 생균제 개발을 위한 목적으로써 가금티프스 원인균인 Salmonella gallinarum의 생육을 저해시킬 수 있는 길항균주를 토종닭의 내장으로부터 분리하여 생육특성과 길항물질 생산성을 조사하고, 이 균주를 분류학적으로 동정하였다. 분리된 길항균주는 Bacillus amyloliquefaciens와 98% 상동성을 나타내어 최종적으로 Bacillus amyloliquefaciens Y3로 명명하였다. 0.3% maltose, 0.2% $NH_4Cl,\; 37^{\circ}C$ pH 7에서 균생육 및 길항물질의 생산능이 가장 우수하였으나 장내 담즙에 대한 내성은 크게 나쁘지 않을 것으로 확인되어졌다. 생산된 길항물질을 추정하여 본 결과 분자량이 10,000보다 작은 저분자물질이었으며 $80^{\circ}C$에서 20분간 열처리한 후에도 80%의 활성을 유지하는 내열성 물질임을 확인할 수 있었다. 향후 선발되어진 Bacillus amyloliquefaciens Y3가 생산해내는 길항물질에 대한 연구와 개량을 통하고 장내 정착성 실험을 거쳐 우수균주로 확인되면 양계산업에 사용될 우수한 생균제로 개발이 가능할 것이라 생각된다.

• 한국작물학회지
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• 제35권1호
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• pp.58-64
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• 1990

최근 국내에서 연구가 시작되고 있는 신규 식물생장조정제인 brassinolide류와 기존의 auxin류를 혼용하였을 경우 상호작용성을 구명하여 농업적 이용의 기초자료를 얻고자 몇가지 생물검정법을 이용하여 상호작용의 결과를 분석해 본 결과를 요약하면 다음과 간다. 1. 벼 엽신기부굴절검정에서는 두 화합물의 저농도 혼용조합에서 길항적인 반응을 보였으나, 대부분의 조합에서는 상가 또는 상승작용을 하였으며, 고농도의 혼용일수록 상승효과가 높았고, IAA가 2, 4-D에 비해 다소 혼용효과가 높았다. 2. 귀리 자엽소신장검정에서는 HBR의 농도에 관계없이 IAA 0.1ppm 이하에서는 상승작용을 하였으나 0.3ppm 이상의 혼용에서는 상가적인 반응을 나타내었다. 3. 무 하배축신장검정에서는 자엽의 유무에 의해 반응이 다르게 나타났는데, 자엽을 제거한 절편에서는 IAA 3ppm과 HBR과의 혼용조합을 제외하고는 대부분의 혼용조합이 길항적인 반응을 보였다. 4. 이상에서와 같이 검정방법간 혼용효과가 뚜렷한 차이가 있었으며, 공시재료에 따라 상호작용의 효과가 다르게 나타났는데 auxin의 함량이 비교적 높은 생장점을 가진 절편에서는 대체로 길항작용을 보인 반면, 선단부를 제거하여 내생호르몬이 불안정한 절편에서는 상가 또는 상승작용을 보였다.

• Journal of Microbiology and Biotechnology
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• 제5권6호
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• pp.341-345
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• 1995

Seventy four microorganisms, which have antagonistic activity against to Fusarium culmorum, were tested for their inhibitory effect on colony development of obligate biotroph Erysiphe graminis f. sp. hordei Marchal, the causal agent of powdery mildew on barley plants. Of these, 13 actinomycetes isolates were shown to reduce the colony development of mildew completely by application of their 10% cell-free culture filtrates on barley leaves. An Isolate, A252, was the most powerful antagonist and its antifungal activity was further assessed. The colony development of mildew was significantly reduced by application of the 1% cell-free culture filtrate of isolate A252. In comparison to the control, the protective and curative application of 10% cell-free culture filtrate from A252 showed 88.5% and 96.1% reduction of colony numbers respectively. By the protective application, 68.3% of the inhibition was observed after 9 days of treatment, thus showed prolonged inhibitory effect. In vitro test, complete inhibition of the mycelial growth of Microdochium nivale was achieved by the treatment of 1% A252 culture filtrate and 80.2% of inhibition was observed by the 0.1% treatment.

• Journal of Microbiology and Biotechnology
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• 제17권5호
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• pp.858-864
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• 2007

This study investigated the antibacterial activities of sophoraflavanone G from Sophora flavescens in combination with two antimicrobial agents against oral bacteria. The combined effect of sophoraflavanone G and the antimicrobial agents was evaluated using the checkerboard method to obtain a fractional inhibitory concentration(FIC) index. The sophoraflavanone G+ampicillin(AM) combination was found to have a synergistic effect against S. mutans, S. sanguinis, S. sobrinus, S. gordonii, A. actinomycetemcomitans, F nucleatum, P. intermedia, and P. gingivalis, whereas the sophoraflavanone G+gentamicin(GM) combination had a synergistic effect against S. sanguinis, S. criceti, S. anginosus, A. actinomycetemcomitans, F nucleatum, P. intermedia, and P. gingivalis. Neither combination exhibited any antagonistic interactions(FIC index>4). In particular, the MICs/MBCs for all the bacteria were reduced to one-half$\sim$one-sixteenth as a result of the drug combinations. A synergistic interaction was also confirmed by time-kill studies for nine bacteria where the checkerboard suggested synergy. Thus, a strong bactericidal effect was exerted through the drug combinations, plus in vitro data suggested that sophoraflavanone G combined with other antibiotics may be microbiologically beneficial rather than antagonistic.

• 한국환경농학회지
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• 제29권1호
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• pp.86-91
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• 2010

This study was carried out to assess the antifungal potential of R. oligosporus and its ethyl acetate (EtOAc) extract against the fungal pathogens causing anthracnose disease in apple fruits using disc diffusion, antagonistic effect and morphological abnormalities in fungal mycelia. The percentage of inhibition of antifungal effect of the ethyl acetate extract (5 ${\mu}l$ $disc^{-1}$) of the R. oligosporus against C. acutatum KACC 40848, C. gloeosporioides KACC 40897, C. higginsianum KACC 40806, C. orbiculare KACC 40808, C. coccodes KACC 40008, C. musae KACC 40947, C. boninense KACC 40893, C. liliacearum KACC 40981, C. caudatum KACC 41028 and Colletotrichum sp. KACC 40811 was found to be 44.4, 35.5, 40, 31.1, 33.3, 37.7, 40, 51.1, 28.8 and 28.8%, respectively. Also the fungus R. oligosporus showed potential antagonistic effect of antifungal activity against the tested pathogens of Colletotrichum spp. Further, R. oligosporus had a potential detrimental effect on the morphology of the tested fungi of Colletotrichum spp. such as wrinkle abnormalities, abnormal cell formation, lysis of mycelium, empty cell formation, distorted cell formation and breakage of the mycelium. These findings strongly support the role of R. oligosporus to serve as a potential antifungal agent to control plant pathogenic fungi causing anthracnose disease in apple fruits.

• 미생물학회지
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• 제11권4호
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• pp.175-180
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• 1973

This study was attempted to see more clear relationships among the enterobacteria, especially between the intestinal normal flora and pathogenic bacteria. It has been known that some intestinal normal flora produce the bactrial metabolites that are harmful to other enteric bacteria. One of the metabolites is known as colicin, the protein fraction, which possesses certain degree of inhibitory effect against other bacterial growth fraction, whih possesses certain degree of inhibitory effect against other bacterial growth. As a preliminary study for a colicin purification, the antagonistic effect of E, coli to groups of Salmonella and Shigella has been studied by means of in vitro quantitative culture method. 1. E.coli showed definite inhibitory effects aganist both Salmonella and Shigella groups in the mixture of two organisms. 2. The inhibitory effects of E.coli in the E.coli-Salmonella and the E.coli-Shigella mixture occurred from 4 hours incubation following the inoculation. 3. Even the complete inhibition of pathogenic enteric bacterial growth was noticed in the E.coli-Salmonella mixture at overnight incubation. 4. Among the diluted mixtures, 1:100, 1:1,000, and 1:10,000, survival rate of pathogenic enteric bacteria in the mixtures with E.coli showed least affected at the 1:1,000 dilution. 5. It was found that the antagonistic effect aganist groups of Salmonella-shigella was depending upon the groups of the genera.

• 한국식물병리학회지
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• 제14권3호
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• pp.268-277
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• 1998

The production of Korean ginseng, one of the most important medicinal root crops, is limited by many factors including soil sickness, root rots in fields as well as during storage prior to consumption. Although much research has been conducted on the diseases in field condition, little information is available on the control of postharvest roots rots. To obtain better management strategy of postharvest root rots in ginseng, biological control using antagonistic bacteria was attempted. Of 208 bacteria obtained form suppressive soil samples, 4 were selected based on the inhibitory effect on mycelial growth of two major causal fungi for postharvest root rots in ginseng, Botrytis cinerea and Fusarium solani. The culture filtrates of these bacterial antagonists greatly inhibited the conidial germination of both pathogenic fungi and produced abnormal morphology such as swollen germ tubes in F. solani and vacuolation of nongerminated conidia in B. cinerea. The population levels of bacterial antagonists on the ginseng roots were gradually increased up to 8 days of incubation. Postharvest root rots of ginseng caused by f. solani and B. cinerea were controlled in dipping tests in the ranges of 60∼80% by antagonistic Bacillus spp. obtained from suppressive soil. These results suggest that biological control using these antagonistic bacteria would be an alternative strategy to control postharvest root rots in ginseng.