• Journal of Applied Biological Chemistry
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• 제58권3호
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• pp.253-258
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• 2015

Xanthomonas oryzae pv. oryzae (Xoo), X. campestris pv. vesicatoria (Xcv), and Pectobacterium carotovorum pv. carotovorum (Pcc) are the causative agents of bacterial blight in rice, bacterial spot in pepper, and bacterial soft rot in carrot and cabbage, respectively. To isolate novel microbial extracts with antimicrobial activities against these bacteria, approximately 5,300 different Streptomyces extracts were prepared and tested. Microbial cultures from various Streptomyces strains isolated from the Jeju Island, Baekam, Mankyoung river, Jiri mountain etc. in Korea were extracted into three different factions -secreted hydrophobic, secreted hydrophilic, and mycelia- using ethyl acetate, water, and methanol. Initially, 34, 29, and 10 extracts were selected as having antibacterial activities against Xoo, Xcv, and Pcc, respectively. Extracts 1169G4, 1172E9, and 1172E10 had the highest growth inhibition activities against both Xoo and Xcv, and extracts 1151H7 and 1152H7 showed the highest growth inhibition activities against Pcc.

• Applied Biological Chemistry
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• 제35권1호
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• pp.30-35
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• 1992

Polyvinyl alcohol(PVA)을 탄소원으로 이용할 수 있는 세균 J2W 균주와 J2Y균주를 토양으로 부터 분리하였다. 분리된 이들 균주는 각각 별도의 순수배양으로는 PVA를 이용할 수 없었으나 이들 균주를 혼합배양 하였을 경우는 PVA를 분해 이용할 수 있었으며, 또한 PVA의 중합도(중합도 500, 1500, 2000)에 관계없이 이용할 수 있었다. 이들 두 균주는 다른 PVA 이용 공생균주 Pseudomonas PW와 Pseudomonas G5Y와 재구성하여 혼합배양 하였을 때 J2Y균주와 Pseudomonas PW, J2W 균주와 Pseudomonas G5Y 균주와의 혼합배양에서는 PVA를 이용할 수 있었다. 이들 두 균주는 동정 결과 J2W균주는 Pseudomons pseudomallei 근연균으로, J2Y는 Xanthomonas campestris 근연균으로 동정되었다.

• The Plant Pathology Journal
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• 제27권1호
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• pp.89-92
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• 2011

Cyclic AMP receptor-like protein (Clp), is known to be a global transcriptional regulator for the expression of virulence factors in Xanthomonas campestris pv. campestris (Xcc). Sequence analysis showed that Xanthomonas oryzae pv. oryzae (Xoo) contains a gene that is strongly homologous to the Xcc clp. In order to determine the role of the Clp homolog in Xoo, a marker exchange mutant of $clp_{xoo4158}$ was generated. Virulence and virulence factors, such as the production of cellulase, xylanase, and extracellular polysaccharides (EPS) and swarming motility were significantly decreased in the $clp_{xoo4158}$ mutant. Moreover, the mutation caused the strain to be more sensitive to hydrogen peroxide and to over-produce siderophores. Complementation of the mutant restored the mutation-related phenotypes. Expression of $clp_{xoo4158}$, assessed by reverse-transcription realtime PCR and clp promoter activity, was significantly reduced in the rpfB, rpfF, rpfC, and rpfG mutants. These results suggest that the clp homolog, $clp_{xoo4158}$, is involved in the control of virulence and resistance against oxidative stress, and that expression of the gene is controlled by RpfC and RpfG through a diffusible signal factor (DSF) signal in Xanthomonas oryzae pv. oryzae KACC10859.

• Journal of Microbiology
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• 제45권2호
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• pp.175-178
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• 2007

An endonuclease from Xanthomonas oryzae pathovar oryzae KACC 10331, XorII, was recombinantly produced in Escherichia coli using a T7 system. XorII was purified using a combination of ion exchange and immobilized metal affinity chromatography (IMAC). An optimized washing protocol was carried out on an IMAC in order to obtain a high purity product. The final amount of purified XorII was approximately 2.5 mg/L of LB medium. The purified recombinant XorII was functional and showed the same cleavage pattern as PvuI. The enzyme activity tested the highest at $25^{\circ}C$ in 50 mM NaCl, 10 mM Tris-HCl, 10 mM $MgCl_{2}$, and 1 mM dithiothreitol at a pH of 7.9.

• Journal of Applied Biological Chemistry
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• 제44권4호
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• pp.173-176
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• 2001

This report concerns the role of indole-3-acetic acid (IAA) in bacterial pustule disease of soybean. Pustule production in soybean leaves caused by Xanthomonas axonopodis pv. glycines was accompanied by a drastic increase in IAA content of host tissues. The phytopathogenic bacterium synthesized IAA in a tryptophan concentration-dependent manner when grown in a defined minimal medium. In complex media, however, the pathogen showed no response to tryptophan feeding, implying that the bacterial biosynthetic machinery of IAA is strictly regulated by nutrient availability of its growth environments. The results may suggest that IAA of bacterial origin and tryptophan of plant origin be involved in the process of pustule symptom development in soybean.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.727-730
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• 2001

Xanthomonas oryzae #5로부터 클로닝 된 CFTase 의 functional domain의 분석을 위해 CFTase의 recombinant deletion mutant를 구성하고, recombinant protein을 분리, 정제하였다. 분리, 정제한 recombinant protein의 활성을 측정한 결과 C-terminal이 deletion 된 mutant는 cyclization 반응이 소실 되었다. 이와 같은 결과로부터 CFTase의 C-terminal 은 cyclization 반응의 중요한 functional domain 이다.

• 한국미생물·생명공학회지
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• 제17권4호
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• pp.277-282
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• 1989

Xanthomonas campestris에 의한 생물고분자 xanthan gum 생산의 경우 배양액은 xanthan gum의 농도가 증가하면서 고점도의 non-Newtonian 유체로 변하게 되는데 이로 인하여 영양분과 산소의 물질전달이 저해를 받아 미생물의 성장과 xanthan gum의 생합성이 제한을 받게 된다. 본 연구에서는 교반속도를 변화시켜 가면서 회분식 및 유가식 배양을 하였으며 산소전달계수 측정실험을 하여 물질전달의 영향을 조사하였다. 미생물의 성장속도는 산소전달전달계수 변화에 대해 크게 영향을 받지 않았지만 xanthan gum의 생산속도는 산소전달계수값에 크게 의존하였다.

• Journal of Microbiology and Biotechnology
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• 제4권4호
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• pp.285-289
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• 1994

An insecticidal crystal protein gene, cryIA(c), from Bacillus thuringiensis HD-73 was integrated into the chromosome of a xanthan-producing bacterium, Xanthomonas campestris XP92. The cryIA(c) gene expression cassette was constructed that placed the gene between the trc promoter and rrnB transcriptional terminator. The $lacl^q$ gene was also included to prevent the expression of cryIA(c) gene in X campestris cells. Southem blot analysis confirmed the integration of the cryIA(c) gene expression cassette in chromosome of X campestris XP92 transconjugant. Expression of the insecticidal crystal protein was confirmed by Western blot analysis and bioassay against the larvae of Hyphantria cunea (Lepidoptera： Arctiidae) and Plutella xylostella (Lepidoptera：Plutellidae).

• Journal of Microbiology and Biotechnology
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• 제23권9호
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• pp.1287-1292
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• 2013

Extracellular biogenic synthesis of silver nanoparticles with various shapes using the rice bacterial blight bacterium Xanthomonas oryzae pv. oryzae BXO8 is reported. The synthesized silver nanoparticles were characterized by UV-Vis spectroscopy, powder X-ray diffractometry (XRD), scanning electron microscopy, energy dispersive X-ray spectrometry, and high-resolution transmission electron microscopy (HR-TEM). Based on the evidence of HR-TEM, the synthesized particles were found to be spherical, with anisotropic structures such as triangles and rods, with an average size of 14.86 nm. The crystalline nature of silver nanoparticles was evident from the bright circular spots in the SAED pattern, clear lattice fringes in the high-resolution TEM images, and peaks in the XRD pattern. The FTIR spectrum showed that biomolecules containing amide and carboxylate groups are involved in the reduction and stabilization of the silver nanoparticles. Using such a biological method for the synthesis of silver nanoparticles is a simple, viable, cost-effective, and environmentally friendly process, which can be used in antimicrobial therapy.

• 한국식물병리학회지
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• 제12권2호
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• pp.156-161
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• 1996

세계적으로 구리약제에 대해서 저항성을 나타내는 균주들이 발견되있으며, 이들은 구리약제의 방제효과를 감소시켰다. 국내에서도, 구리 저항성 균주 Xanthomonas campestris. pv. vesicatoria HN94-2, -3, -4, -5, -6 들이 천안지역의 고추재배지에서 처음으로 분리되었으며, 이들 균주들의 nutrient agar에서 황산구리(CuSo\ulcorner)에 대한 최소억제농도(minimum inhibitory concentration, MIC)는 1.4~1.6 mM이었다. 이들은 모두 황산아연(ZnSO\ulcorner)에 대해서는 감수성을 보여, 구리저항성 균주에 대한 방제약제로서 아연 함유 약제를 사용할 수 있을 것이다. 분리된 균주중 HN94-2와 HN94-6을 이용하여 접합(conjugation)을 통해 구리저항성의 전파를 실험한 결과, 이들 두 균주 모두 구리감수성 균주에게 4.3$\times$10\ulcorner에서 1.0$\times$10\ulcorner(transconjugant/donor)의 정도로 구리 저항성이 전이되었다. 이들 HN94-2와 HN94-6 균주의 구리정항성 유전자들은 약 200 kb 정도의 커다란 플라스미드(plasmid)에 존재하며, 이들은 각각 pXVK9402와 pXVK9406이라 명명되었다.