• 식물병연구
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• 제23권2호
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• pp.114-149
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• 2017

전 세계적으로 주요 작물에서 식물 병원성 해충 및 선충으로 인한 작물 생산량 감소 등의 경제적 손실이 심각하다. 우리나라의 경우 시설 재배지의 연작으로 인해 해충과 선충의 발생이 증가하여 작물의 피해가 점차 증가하고 있는 추세다. 현재 주로 사용되고 있는 식물병원성 해충 및 선충의 방제법은 사용이 편리하고 비용이 저렴한 화학적 방제법을 이용하고 있지만 화학 농약의 남용으로 인한 약제 저항성이 발생하고, 화학 약품으로 인한 인체 유해성 및 환경오염 문제가 대두되고 있다. 이로 인해 최근 친환경적인 방제에 관한 지속적인 연구와 관심이 높아지면서 식물병원성 해충과 선충에 대하여 살충/살선충 활성을 나타내는 미생물을 생물학적 방제법으로 이용하기 위한 시도가 증가하고 있다. 본 리뷰에서는 식물병원성 해충과 선충에 대한 살충/살선충 활성을 나타내는 세균, 진균, 바이러스에 의한 살충 및 살선충 사례와 기전들을 소개하였다. 이러한 미생물의 활성은 외피 분해효소와 독소물질생산을 통한 직접적인 작용기전과 기주 식물의 저항성 유도를 통한 간접적인 작용기전에 의해서 일어난다. 본 리뷰를 통하여 선충과 해충에 대한 생물학적 방제법과 그 분자 작용기전에 대한 이해를 돕고, 최신 살충 및 살선충 연구들을 소개함으로써 국내의 농민들과 연구자들의 미생물을 기반으로 한 친환경적 해충 및 선충의 방제법에 대한 저변확대를 기대한다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.120.2-120
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• 2003

Agrobacterium vitis is a causal agent of crown-gall disease on grapevine. In Korea, grapevine variety (GeoBong) have severely been infected by the bacteria since stems of the variety were buried in soil for overwintering. Infection ratio over 70-80％ was observed on 7 years old GeoBong grapevine in Ansung and Cheonan. PCR specific primers for A. vitis strains were designed using nucleotide sequences of vir A gene in Ti-Plasmid, pheA gene in chromosomal DNA and a URP-PCR polymorphic band. Three hundred bacterial strains were isolated from the different 80 galls formed on GeoBong grapevine in Cheonan and Ansung of Korea and were screened to identify A. vitis using the three specific PCR primers for Agrobacterium vitis. Twenty-four bacterial strains that are detected by the primers were further confirmed by pathogenicity and biochemical methods. To investigate the genomic diversity of the bacterial strains, twenty primers of 20 mer referred to universal rice primers (URP) were applied for PCR fingerprinting, Of them, URP2R and URP2F primers could effectively be used to detect polymorphism within the bacterial strains.

• Journal of Microbiology and Biotechnology
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• 제20권4호
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• pp.651-658
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• 2010

Garcinia is commonly found in Malaysia, but limited information is available regarding endophytic fungi associated with this plant. In this study, 24 endophytic fungi were successfully recovered from different parts of two Garcinia species. Characterization of endophytic fungi was performed based on the conserved internal transcribed spacer (ITS) region sequence analysis and the antimicrobial properties. Results revealed that fruits of the plant appeared to be the highest inhabitation site (38%) as compared with others. Glomerella sp., Guignardia sp., and Phomopsis sp. appeared to be the predominant endophytic fungi group in Garcinia mangostana and Garcinia parvifolia. Phylogenetic relationships of the isolated endophytic fungi were estimated from the sequences of the ITS region. On the other hand, antibacterial screening showed 11 of the isolates possessed positive response towards pathogenic and nonpathogenic bacteria. However, there was no direct association between certain antibacterial properties with the specific genus observed.

• 한국약용작물학회지
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• 제14권4호
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• pp.202-205
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• 2006

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.

• 식물병과 농업
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• 제5권2호
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• pp.69-76
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• 1999

Acidovorax avenae subsp. avenae is the causal pathogen of several hosts including oats corn foxtail millet wheatgrass sugarcane and rice. The pathogen is a seedborne pathogen of rice and known to occur widely in rice growing countries. The pathogen cause inhibition of germination brown stripe on the leaf curling of the leaf sheath and abnormal elongation of the mesocotyl of irce. Bacterial colonies grow slowly and are convex circular and creamy with tan to brown center. The causal baterium is Gram-negative and rod shape with a single polar flagellum Nonfluorescence poly-$\beta$-hydroxybutyrate accumulation and precipitate formation around the colony on the medium are useful in the differentiation of this bacterium from other subspecies of A. avenae as well as nonfluorescent bacteria pathogenic to rice. This bacterium has belonged to the genus of Psdeudomonas but recently was transferred to the new genus Acidovorax on the basis of bacteriological and molecular biological data. However the difference of biochemical characteristics protein profile of the cell and host range among strains should be more clarified. To develop an effective control strategy for this disease understanding of detailed life cycle of the disease ritical environmental factors affecting disease development on each host and relationship to grain discoloration of rice are prerequisite. Although the affected area has been world-widely reported there is on recent progress on the understanding of the bacteriological and ecological characteristics of the causal bacterium and control means of the disease.

• The Plant Pathology Journal
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• 제19권6호
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• pp.280-283
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• 2003

A soybean-sprout rot epidemic occurred in a mass production soybean sprout factory in 2000 and 2001 in Korea, which caused up to 20% production loss. Among the causal pathogenic bacteria and fungi, Pythium deliense was found to be the dominant pathogen of severe root and hypocotyls rot, particularly in recirculating water system. An average of 90% of the isolated fungi from the rotted sprout on potato dextrose agar were Pythium sp. The fungal density of Pythium in the sampled water was monitored in the recycled water system for 1 year using a selective medium (com meal agar with Pimaricin, 10 mg； Rifampicin, 10 mg； and Ampicillin, 100 mg per 1 liter). The drained water from the soybean-sprout cultivation always had a certain amount of fungus in it. The removal of Pythium from the recycling water system must be thorough, safe, and environment friendly. However, the pathogen in the water was easily found even after ozone and chlorine treatments, which were devised on the recycling system for the removal of microorganisms. 5-$\mu\textrm{m}$ pore size filter was applied and was able to successfully control the disease. As the sprout industry increasingly shifts into mass production, the demand for water will increase continuously. Recycling water for sprout production is eco-friendly. However, a process must be devised to be able to first decompose organic matters before Pythium zoospores are filtered.

• The Plant Pathology Journal
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• 제38권4호
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• pp.355-365
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• 2022

Erwinia amylovora and E. pyrifoliae are the causative agents of destructive diseases in both apple and pear trees viz. fire blight and black shoot blight, respectively. Since the introduction of fire blight in Korea in 2015, the occurrence of both pathogens has been independently reported. The co-incidence of these diseases is highly probable given the co-existence of their pathogenic bacteria in the same trees or orchards in a city/district. Hence, this study evaluated whether both diseases occurred in neighboring orchards and whether they occurred together in a single orchard. The competition and virulence of the two pathogens was compared using growth rates in vitro and in planta. Importantly, E amylovora showed significantly higher colony numbers than E. pyrifoliae when they were co-cultured in liquid media and co-inoculated into immature apple fruits and seedlings. In a comparison of the usage of major carbon sources, which are abundant in immature apple fruits and seedlings, E. amylovora also showed better growth rates than E. pyrifoliae. In virulence assays, including motility and a hypersensitive response (HR), E. amylovora demonstrated a larger diameter of travel from the inoculation site than E. pyrifoliae in both swarming and swimming motilities. E. amylovora elicited a HR in tobacco leaves when diluted from 1:1 to 1:16 but E. pyrifoliae does not elicit a HR when diluted at 1:16. Therefore, E. amylovora was concluded to have a greater competitive fitness than E. pyrifoliae.

• 한국미생물·생명공학회지
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• 제39권3호
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• pp.308-312
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• 2011

Plant lactic acid bacteria were isolated from plant-associated fermentative foods and crops, and their probiotic properties were investigated. Isolates K27 and O2 were isolated from Kimchi and onion, and identified as Lactobacillus plantarum on the basis of 16S rRNA gene analysis. The two strains were highly resistant to acid (an MRS broth at pH 2.5), where the survival rates of L. plantarum K27 and L. plantarum O2 were 90.2% and 97.3%, respectively. L. plantarum K27 and L. plantarum O2 also showed high bile resistance to 0.5% oxgall, with a more than 70% survival rate. They showed an inhibitory effect against pathogenic strains of Escherichia coli KCCM 40880 and Pseudomonas aeruginosa ATCC 10145. The antibacterial effect of the two strains was probably due to the presence of lactic acid. ACE inhibitory activities of the two strains ranged from 72.8% to 80.6% in MRS broth. Notably, the two strains showed high ACE inhibitory activity (89.2~98.2%) in MRS broth containing 10% skim milk. Antioxidant activity was tested by DPPH radical scavenging activity, with antioxidant activities of the strains being in the range of 56.8~61.5%. The results obtained in this study suggest that L. plantarum K27 and L. plantarum O2 may be potential probiotic starter cultures with applications with fermentative products.

• Journal of Microbiology and Biotechnology
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• 제20권12호
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• pp.1614-1623
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• 2010

Bacteria were isolated from roots of sugarcane varieties grown in the fields of Punjab. They were identified by using API20E/NE bacterial identification kits and from sequences of 16S rRNA and amplicons of the cpn60 gene. The majority of bacteria were found to belong to the genera of Enterobacter, Pseudomonas, and Klebsiella, but members of genera Azospirillum, Rhizobium, Rahnella, Delftia, Caulobacter, Pannonibacter, Xanthomonas, and Stenotrophomonas were also found. The community, however, was dominated by members of the Pseudomonadaceae and Enterobacteriaceae, as representatives of these genera were found in samples from every variety and location examined. All isolates were tested for the presence of five enzymes and seven factors known to be associated with plant growth promotion. Ten isolates showed lipase activity and eight were positive for protease activity. Cellulase, chitinase, and pectinase were not detected in any strain. Nine strains showed nitrogen fixing ability (acetylene reduction assay) and 26 were capable of solubilizing phosphate. In the presence of 100 mg/l tryptophan, all strains except one produced indole acetic acid in the growth medium. All isolates were positive for ACC deaminase activity. Six strains produced homoserine lactones and three produced HCN and hexamate type siderophores. One isolate was capable of inhibiting the growth of 24 pathogenic fungal strains of Colletotrichum, Fusarium, Pythium, and Rhizoctonia spp. In tests of their abilities to grow under a range of temperature, pH, and NaCl concentrations, all isolates grew well on plates with 3% NaCl and most of them grew well at 4 to $41^{\circ}C$ and at pH 11.

• 한국미생물·생명공학회지
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• 제34권2호
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• pp.101-108
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• 2006

Phytophthora sp.의 균사성장을 특이적으로 저해하는 토양 미생물인 YNB54 균주의 정확한 분류적 위치를 밝히기 위해 Biolog GN2, API 20E와 같은 상업적 생화학 kit, 16S rDNA, DAN-DNA hybridization, GC함량, MIDI 등의 분석을 수행하였다. 다양한 생화학적 kit를 사용한 동정 결과는 이 균주가 다른 어떤 종보다 Enterobacter cloacae와 E. cancerogenus에 보다 더 가까움을 보여주었다. 또한 DAN-DNA hybridization, GC함량, MIDI 분석의 결과들 역시 다른 속 (Citerobacter, Klebsiella, Leclercia)보다 Enterobacter 속에 더 유사함을 암시해 주었다. 그러나 16S rDNA분석에서 이 균주는 Citrobacter freundii(99.4%)와 동일 그룹으로 구분되었지만 Enterobacter, Leclecia, Klebsiella 속 등과도 98%이상의 상동성을 보여주는 polyphyletic 특성을 보였다. 결론적으로 YNB54의 분류 동정을 위한 우리의 조사들은 이 균주가 유전적으로 다양하고 지금까지 아는 것보다 분류학적으로 더 복잡함을 암시해줌에도 불구하고 Enterobacter속임이 가장 유력하다는 것을 보여 주었다.