Cladobotryum mycophilum is the causal agent of cobweb disease of commercial mushrooms. Symptoms were noticed as round, fleshy, yellowish brown lesions on mushroom caps and progressed when the parasitic fungus formed white cobweb circular colonies on dead or damaged pinheads, spread on the surface of the casing. Two gram-positive bacterium were isolated from mushroom media that markedly showed the antagonistic activity against C. mycophilum.. These isolates were identified as Bacillus altitudinis and Bacillus subtilis by analysis of the cultural, morphological and physiological characteristics, and analysis of the 16S rDNA. The isolated bacteria is saprophytic but not parasitic nor pathogenic to cultivation mushroom. The isolated bacteria cell was sufficient for inhibition in vitro for C. mycophilum. Control efficacy of browning disease of Bacillus altitudinis treatment was 78% on Agaricus bisporus. The optimal culture medium was determined as follows: 3% Soluble startch, 10% Soytone, 1% (NH4)2HPO4, 1 mmol KCl, and 0.5% L-asparagin at pH 6.0 at 30°C. Control efficacy of browning disease of Bacillus subtilis treatment was 71% on Agaricus bisporus. The optimal culture medium was determined as follows: 1.5% Xylose, 2% Soytone, 1% NH4H2PO4, 7 mmol CaCl2, and 0.5% Histidine at pH 6.0 at 25°C. Accordingly, the suppressive bacterium may be useful in future for the development of biocontrol system and the construction of genetically modified edible fungi resistant to the disease caused by C. mycophilum.

Mushroom is cultivated as one of the major economical crops in many areas in Korea. The total production has steadily increased from approximately 198,563 M/T in 2009 to 208,941 M/T in 2012. Several fungus are known as the causal agents of diseases of the cultivated button mushroom (Agaricus bisporus) and oyster mushroom (Pleurotus ostreatus). Trichoderma harzianum is the causal agent of brown blotch disease of commercial mushrooms. Colonization of mushroom caps by the bacterium results in development of brown or cream lesions on pileus and stipe. These lesions are slightly concave spots and can be round or spreading. Antagonists against Trichoderma harzianum, CAM33 were selected and their control efficacy of green mould disease was investigated in this study. The CAM33 strain was selected as antagonistic bacterium by inhibition zone method and it was identified as Bacillus methyrotrophicus. by the cultural, morphological and physiological characteristics, and analysis of the 16S rDNA. The isolated bacterium is saprophytic but not parasitic nor pathogenic to cultivation mushroom. The isolated bacterium for Trichoderma harzianum cell, was sufficient for inhibition in vitro. Inoculation of the isolated bacterium prevents the development of bacterial disease in Trichoderma harzianum. Control efficacy of browning disease of strain CAM33 treatment was 77% on Agaricus bisporus. The optimal culture medium for the antagonistic bacteria growth was determined as follows: 3.0% Saccharose, 1.5% Soytone, 1.0% (NH4)2HPO4, 10 mmol MgSO4, and 2.0% Glutamic acid at pH 6.0 at 25°C. The suppressive bacterium may be useful in future for the development of biocontrol system and the construction of genetically modified edible fungi resistant to the disease caused by Trichoderma harzianum.

Mushroom is cultivated as one of the major economical crops in many areas in Korea. The total production has steadily increased from approximately 186,400 M/T in 2007 to 190,111 M/T in 2011. The button mushroom, Agaricus bisporus, showed the 5th production to 13,052 M/T in 2011. Several bacteria are known as the causal agents of diseases of the cultivated button mushroom (Agaricus bisporus) and oyster mushroom (Pleurotus ostreatus). Pseudomonas agarici is the causal agent of browning disease of commercial mushrooms. In this study, antagonistic bacteria to P. agarici were selected in vitro tests using confrontation bioassay and paper disk diffusion assay. The most active bacteria, HC12 were selected and their control efficacy of brown blotch disease was investigated in this study. After proceeding antagonistic test, HC12 was selected as a strong antagonist against P. agarici and the HC12 strain was identified as Alcaligenes sp. with the cultural, physiological and biochemical properties and analysis of the 16S rRNA. The optimal culture medium for the antagonistic bacteria growth was determined as follows: 0.5% dextrin, 1.5% yest extract, 1% NaNO3, 0.5% KH2PO4, and 1.5% L-asparagin at pH 9.0 at 30℃. Control efficacy of browning disease by HC12 treatment was 63% on Agaricus bisporus..

본 연구는 친환경적으로 시금치 노균병을 방제하기 위하여 식물정유, 길항미생물 및 난황유의 병발생 억제효과를 검정하여 화학농약 대신에 이용할 수 있는 친환경제제로서의 가능성을 검토하였다. 5종의 식물정유 가운데 노균병 방제효과는 1회 처리구와 1주 간격 2회 처리구 모두 Eucalyptus approximans 오일의 병원균 억제효과가 60% 정도로 가장 높은 것으로 나타났다. 반면에 토양에서 선발된 길항균 세 종류의 시금치 노균병 방제효과는 모두 20% 이하로 식물정유 처리보다 낮게 나타났다. 난황유 0.3%와 0.5%농도에서 1주일간격 2회 처리구에서 병원균 억제율이 각각 84.5%와 91.5%로 억제되어 가장 효과가 우수한 것으로 나타났다.

This study was carried out investigate to availability of commercial microbial pesticide and antibacterial activity of isolates isolated from different mushroom media. Ten commercial microbial pesticide and EM liquid were collected from different company. EM of these one has been used for control of mushroom disease and growth promotion at the mushroom farms. The density of bacteria and yeast in EM cultural liquid was higher than those of the crude liquid. The pH values of EM showed the low acid levels(pH 3.5~3.9) by organic acid secreted from microorganism. The kinds of organic acid was acetic acid, lactic acid and succinic acid. The dominant bacteria isolated from EM liquid was Lactobactillus sp.(21 strains), Acetobacter sp.(9 strains), PaeniBacillus sp.(9 strains) and others(12 strains). The organic acid bacteria isolated from fermentation foods( was 92 strains and the dominant genus was Weissella sp.(41 strains), Leuconostoc sp.(21 strains), Enterococcus sp.(9 strains), Lactococcus sp.(9 strains) and others(12 strains). And we isolated 2,500 bacteria from oyster mushroom and button mushroom cultural media for selection of antagonistic bacteria. Thirty five strains of these isolates showed very strong antagonistic activity. These strains were identified Bacillus amyloliquefaciens, Bacillus subtilis, Brevibacterium halotolerans, Pseudomonas libanensis, Stenotrophomonas maltophilia and Alcaligenes faecalis by 16S rDNA analysis.

This study was conducted to investigate the effect of antagonistic bacteria and pathogenic fungi on growth and yields of white clover(Trifo1iurn repens L.) in continuous cropping soil(CCS) and non-continuous cropping soil(NCCS). The gowth experiment of wh

This study was conducted to investigate the effects of antagonistic bacteria and pathogenic fungi on the growth of tall fescue(Festuca arundinacea Schreb.) in continuous cropping soil(CCS) and non-continuous cropping soil(NCCS). Tall fescue was establishe

Botrytis cinerea infects stems and leaves of greenhouse tomatoes and can cause serious economic losses. This study was conducted to develop environment-friendly control method against tomato gray mold. Antagonistic microorganisms (bacteria) were screened for control activity against Botrytis cinerea, both in vitro and in vivo, using stem sections. One hundred bacterial strains were isolated from the rhizospheric soil of various plants including tomato. These strains were screened for growth inhibition of Botrytis cinerea on agar plate by the dual culture and thirty strains showing strongly inhibitory effect against the pathogen were selected first. Among thirty strains, JB 5-12, JB 22-2, JB 22-3, U 4-8 and U46-6 reduced significantly disease incidence, when applied simultaneously with the pathogen. These results suggested that five antagonistic bacteria strains selected have the potential to control tomato gray mold in organic farming.

인삼의 안정적인 생산 및 합리적인 병해방제에 기여하기 위하여 연구를 실시한 결과 갈잎 퇴비에서 분리된 Streptomyces lauretii B8180과 Bacillus subtilis B8856, Burkholderia cepacia B7944 세 균주의 인삼병원균 5종에 대한 항균력이 인정되었으며, 특히 실내실험을 통하여 높은 역병 방제효과가 인정되었다. 그러나 이 실험에서와 같이 식물의 지상부에 길항균을 살포하는 방법을 통하여 역병 방제효과를 높일 수 있을 것으로 생각된다. 이 길항균들은 갈잎 퇴비에서 분리되었기 때문에, 갈잎 퇴비에서 증식시켜 인삼재배 예정지에 투입하면, 억제형 토양 (suppressive soil) 조성을 통한 주요병해 방제가능성도 클 것으로 생각된다.

Sixteen isolates showing relatively strong antagonicity against the ginger rhizome rot pathogen, Pythium zingiberum, were selected among the 155 isolates from ginger rhizome surfaces and rhizospheres of ginger cultivation fields in Wanju, Chonbuk. The isolate, 'HB 26-5'showing the strongest antagonicity was finally selected by testing duration of inhibition effect and pathogenicity to ginger. The isolated antagonistic microorganism, 'HB 26-5' was rod shape, gram positive and formed endospore. The isolate produced acids utilizing glucose, arabinose, xylose and mannitol, and acetoin at VP test, and grew anaerobically. Temperature range for growth was from 10 to 40℃ . Reaction to catalase and gelatin, hydrolysis were positive, and casein hydrolysis and indol production were negative. Based on the mycological characters and the fatty acid composition, it was identified as Bacillus polymyxa. The pathogenicity test of isolated Bacillus polymyxa 'HB 26-5'on 22 crop cultivars resulted that only the lettuce was influenced in germination, and the others were not affected.