• Research in Plant Disease
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• v.7 no.3
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• pp.145-149
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• 2001

A pathogenic bacterium was isolated from galls on Wistaria floibunda at Jinryang of Kyungsan, Kyungbuk, Korea in May, 2000. This bacterium was cultured and tested for pathogenicity on the host. Also its morphological and physiological characteristics were examined. Inoculation with the bacterium isolated from the gall caused the same symptoms as those under natural conditions. On the basis of bacteriological characteristics and pathogenecity on the host plant of the organism, the causal bacterium was identified as Pantoea agglomerans pv. milletiae. This is the first report of this bacterium to occur on W. floribunda plant in Korea. Therefore we proposed to name the disease as "bacterial gall of Wistaria floribunda" by P. agglomerans pv. milletiae.milletiae.

• Korean Journal of Organic Agriculture
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• v.24 no.3
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• pp.571-582
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• 2016

Bacterial fruit blotch (BFB) is one of most important diseases in Cucurbitaceae due to infection of Acidovorax citrulli, causing huge economic losses damage worldwide. This seedborn disease spread rapidly at period of high temperature and humidity. The eco-friendly farming is getting popular. So far there was no effective agent to control BFB in eco-friendly farming. Therefore, effect of the material based on chinese nut-gall extract with antibacterial activity against BFB to was tested against A. citrulli. Different hosts showed various symptoms of BFB. Liquid formulation among exhibited most effective anti-bacterial activity on A. citrulli. Pot experiment in greenhouse showed the potential as an control agent of BFB in cucurbits. The treatment of material based on chinese nut-gall extract showed the positive effect on survival of the watermelon seedling and on the length of the cucumber seedling treated with A. citrulli. We cautiously conclude that the material based on chinese nut-gall extract used in this study may be good agents against major diseases of cucurbits in the future even though it is require to be tested with more study on field test.

• Microbiology and Biotechnology Letters
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• v.24 no.4
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• pp.393-398
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• 1996

In order to develop a lactic acid bacterial powder which can be used as a probiotic for human and animal, a lactic acid bacteria which has high resistance against low pH and ox-gall, and shows a good growth inhibition against E. coli, was isolated from an animal intestine and characterized. The isolated strain was identified as Enterococcus faecium. It had more than 90% of survival at low pH for 2 hours and almost 100% of survival in the presence of 0.3% ox-gall. When co-cultured with E. coli in MRS broth, all of the E. coli cells were killed within 24 hours. The final powdered product of the isolated strain was manufactured after a freeze drying process using an industrial media, and then checked its stability. Its storage stability was 80% for 11 months at 18$\circ$C.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.126-126
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• 2003

Incidence of crown gall on lower stem of chrysanthemum, Chrysanthemum morifolium Ramat., was first observed at Hwasung, Gyeonggi, Korea in 2001, Tumors on the stem were 1.5-2 cm in size and semi-round with rough surface texture of dark brown color. Four strains of bacteria isolated from the tumor tissues were characterized. Their colonies were convex, glistening, circular with an entire edge, and white to tannish-cream in color on PDA plus CaCO$_3$. They were gram negative, oxidase positive, and growing on DIM agar. The bacterial isolates inducing gall formation in chrysanthemum were identified as Agrobacterium tumefaciens based on biochemical and physiological characteristics, fatty acid profile using Sherlock Microbial Identification System, and substrate utilization patterns using Biolog Identification System. Young chrysanthemum plants inoculated with the bacteria developed typical galls within two to three weeks. Seedlings of tomato and slices of carrot roots also produced typical galls two to three weeks after inoculation. This is the first report on crown gall of chrysanthemum in Korea.

• Applied Biological Chemistry
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• v.38 no.2
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• pp.123-128
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• 1995

Several factors affecting on transformation efficiency were studied to establish a Agrobacterium rhizogenes mediated system for the transformation of Populus species, and We could obtaine tansgenic plantlets expressing the introduced gene. Leaf sections were more sensitive than stem sections to kanamycin and thought to be better material for transformant screening. The bacterial density did not affect on the efficiency of transformation over the range of $4{\times}10^5{\sim}7{\times}10^9\;cfu$. The optimum period for co-cultivation was one day or shorter. Both of the optimum concentrations of cefotaxime and ampicillin in the medium were $250\;{\mu}g/ml$ for elimination of bacteria from the inoculated leaf sections. The addition of acetosyringone in the bacterial culture medium increased transformation rate, and the highest rate was obtained at $50\;{\mu}M$ of acetosyringone. The transformed galls could be selectively induced and gown on the growth regulator-free medium or on the medium containing $100\;{\mu}g/ml$ or higher contrition of kanamycin. The roots were induced from the galls incited by A. rhizogenes within 3 weeks on the growth regulator-free medium as well as on the medium containing growth regulators. The plantlets were regenerated from the galls cultured for 6 weeks on the medium containing 0.05 mg/ml of NAA and 0.5 mg/ml of BA. The expressions of the introduced opine gene in the transformed galls and plantlets were confirmed by the analysis of agropine and mannopine.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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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.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.99-102
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• 2001

Recombinant Saccharomyces cerevisiae strains harboring various copy numbers of hirudin gene were developed to study dependency of hirudin expression level on its gene copy number. A linear relationship between the copy number of hirudin expression cassette and hirudin expression level was observed up to 10 copies. A double <5-integration vector truncated wi 디 1 the unnecessary bacterial genes before yeast transformation showed a four-fold increase in transformation efficiency and a 1.3-fold enhancement in hirudin expression level compared with a single <5 system. Gratuitous hirudin expression strain was developed by disrupting the GALl gene of S. cerevisiae. Glucose that was fed in a limited manner effectively supported cell growth and hi겨din expression by the gratuitous strain. Effects of methanol concentrations on hirudin production in recombinant Hansenula polymorpha were investigated in continuous and fed-batch cultures. At a steady-state of continuous culture, an optimum methanol concentration of 1.7 g/L was determined at a dilution rate of 0.18 $h^{-1}$ with 1.8 mg/L ${\cdot}$ h hirudin productivity.

• Journal of Yeungnam Medical Science
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• v.1 no.1
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• pp.41-48
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• 1984

The soil bacterium Agrobacterium tumefaciens is a plant pathogen that cause3 crown gall tumors by infecting the wounded dicotyledonous plants and subsequent integration of bacterial DNA into plant nuclear DNA. Virulent A. tumefaciens strains harbor a large Ti (tumor-inducing) plasmid that carries genes essential for tumorigenesis. In the present study, 13 strains (Malus pumila Mill; $A_{1-3}$, Populus monilifera; $W_{1-6}$, Populus tomentiglandlosa; $P_{1-3}$ and Rosa species; $R_1$) of Agrobacterium isolated in korean crown gall tumors and plasmids were observed in 6 strains ($W_2$, $W_3$, $W_6$, $P_1$, $P_3$ and $A_2$). The test for crown gall tumor formation was resulted only in ATCC15955 and $KW_2$ strains inoculated into the stem of sun flower and the development was observed for 4 and 6 weeks after inoculation. Above two Ti plasmids (pTi) were purified by cesium chloride-ethidium bromide density gradient centrifugation and digested with restriction enzyme and fragments of pTiATCC 15955 and $pTiKW_2$ observed by EcoR I ; 25&27, Hind III; 23&21, BamH I ; each 20 and Hpa I ; 12&27, and sizes of pTiATCC15955 and and $pTiKW_2$ calculated as 200 and 87 kbases. Octopine was isolated from tumor tissue ($W_{1-6}$ and $P_{1-3}$) and these strains confirmed as octopine type.

• The Plant Pathology Journal
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• v.24 no.2
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• pp.207-210
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• 2008

In March of 2003, tumors (galls) were observed on ginseng seedling roots in ginseng seedbeds at Yeoju, Gyeonggi province, Korea. Symptoms were spherical or galls with about 0.5-1.0cm in diameter formed on the upper through middle parts of the primary roots. Bacterial isolates obtained from the root galls were Gram-negative, rod-shaped with peritrichous flagella, aerobic, not forming yellow or orange colonies on nutrient glucose agar, yeast extract-dextrose $CaCO_3$ agar and nutrient-broth yeast extract agar, non-fluorescent on King's B agar, and non-spore forming, which were identical to characteristics of the genus Agrobacterium. They were identified as Agrobacterium tumefaciens with 0.732-0.993 similarities in 100% probability by the Biolog analyses. The 16S rRNA gene partial sequences of the six isolates tested (Genbank Accession EF486308-EF486313) were 100% homologous to those of other A. tumefaciens strains (GenBank accession AF501343, AY701900, AY701898, AY701899). The above results confirmed that this bacterium is A. tumefaciens. Pathogenicity of the bacteria was proved by the inoculation test on carrot root discs and tomato seedlings. This is the first description of A. tumefaciens causing root gall in ginseng seedling. The disease occurred locally and sparsely, but considering its appearances in seedbeds suggests that the ginseng root gall may become a threat to ginseng in Korea.

• The Plant Pathology Journal
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• v.30 no.3
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• pp.288-298
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• 2014

We examined the efficacy of a bacterium for biocontrol of the root-knot nematode (RKN) Meloidogyne hapla in carrot (Daucus carota subsp. sativus) and tomato (Solanum lycopersicum). Among 542 bacterial isolates from various soils and plants, the highest nematode mortality was observed for treatments with isolate C1-7, which was identified as Bacillus cereus based on cultural and morphological characteristics, the Biolog program, and 16S rRNA sequencing analyses. The population density and the nematicidal activity of B. cereus C1-7 remained high until the end of culture in brain heart infusion broth, suggesting that it may have sustainable biocontrol potential. In pot experiments, the biocontrol efficacy of B. cereus C1-7 was high, showing complete inhibition of root gall or egg mass formation by RKN in carrot and tomato plants, and subsequently reducing RKN damage and suppressing nematode population growth, respectively. Light microscopy of RKN-infected carrot root tissues treated with C1-7 showed reduced formation of gall cells and fully developed giant cells, while extensive gall cells and fully mature giant cells with prominent cell wall ingrowths formed in the untreated control plants infected with RKNs. These histopathological characteristics may be the result of residual or systemic biocontrol activity of the bacterium, which may coincide with the biocontrol efficacies of nematodes in pots. These results suggest that B. cereus C1-7 can be used as a biocontrol agent for M. hapla.