• 한국미생물·생명공학회지
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• 제23권3호
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• pp.263-268
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• 1995

A screening was performed to isolate exoploysaccharide-producing microorganisms, which synthesized specific exopolysaccharide for the substitutive of commercial polysaccharides, from natural sources. Soil bacterium, one of 378 mucoid isolates, was finally selected as potential producer of polysaccharides which made the culture broth very viscous and thus examined in detail for optimal medium composition. Isolated strain was identified as Xanthomonas sp. EPS- 1 from the results of morphological and biochemical characteristics. The composition of optimal medium for exopolysaccharide production was as follows: 50 g sucrose, 1.5 g peptone, 2 g KH$_{2}$PO$_{4}$, 2 g MgSO$_{4}$, -7H$_{2}$O, 3 g NaCl, 0.05 g CaCO$_{3}$, 0.07 g FeSO$_{4}$-7H$_{2}$O and 0.05 g MnSO$_{4}$-7H$_{2}$O in 1 liter of distilled water. From the experiments of temperature and pH dependence, the optimal conditions for exopolysaccharide biosynthesis seemed to be 30$\circ$C and 8.0, respectively. About 14.9 gram of maximum exopolysaccharide per liter was obtained at the initial pH 8.0, 30$\circ$C and 250 rpm in a flask culture. The exopolysaccharide EPS-1 had such potential as an emulsifying agent and a gelling agent in comparision with commercial exopolysaccharide.

• International Journal of Industrial Entomology and Biomaterials
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• 제9권2호
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• pp.255-259
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• 2004

Post-infectional biochemical changes due to Xanthomonas campestris pv. mori (Xcm) infection in five elite mulberry varieties viz., $S_1$, $S_{1635}$, $V_1$, RF $S_{175}$ and JRH was studied under inoculated condition. It was revealed that total soluble sugar and protein content was significantly declined in all the varieties due to X. campestris infection. Total phenol content was at par prior to inoculation in all varieties, but it was significantly increased in $S_1$, RF $S_{175}$, $S_{1635}$ and JRH 7 days after inoculation. The correlation coefficient (r) between total soluble sugar and total phenol content was found positive (r = 0.825) and statistically significant. Similarly, correlation coefficient (r) between total soluble protein and phenol content was found positive (r = 0.897) and statistically significant. The present study indicates that X. campestris infected leaves are nutritionally inferior in quality and the duration of phenol production in a mulberry variety play decisive role on disease resistance.nce.

• 대한환경공학회지
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• 제22권10호
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• pp.1851-1859
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• 2000

원유를 분해하는 미생물을 석유화합물로 오염된 토양으로부터 분리하였고, 이들은 Acinetobacter sp. A132, Pseudomonas putida A422, Pseudomonas aeruginosa F721, F722, 그리고 Xanthomonas maltophilia B823으로 동정되었다. 이들 미생물의 유류 분해율을 조사한 결과, strain A132가 $6.04g/L{\cdot}day$로 가장 놓은 분해율을 나타내었다. 탄소수가 10개에서 32개 사이의 n-alkane 화합물을 기질로 사용하여 각각의 화합물에 대한 분해능력을 조사한 결과, strain A132와 F722는 대부분의 기질에 대하여 분해능력을 보였다. Strain A422는 n-alkane 화합물에 대한 분해능력은 높지 않았으나, benzene과 xylene을 분해하는 능력을 가지고 있었다. Strain B823은 원유에서는 조금 생장하였으나, 본 연구에서 사용한 다른 기질들에 대해서는 전혀 분해능력을 보이지 않았다. 한편, n-alkane 혼합화합물에 대한 분해율을 GC/FID로 분석한 결과, strain F722는 $nC_7{\sim}nC_{10}$에서 100%, $nC_{11}{\sim}nC_{24}$에서는 80% 이상 의 높은 분해율을 나타내었다.

• 한국환경과학회지
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• 제23권6호
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• pp.1095-1100
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• 2014

Keratin wastes are generated in excess of million tons per year worldwide and biodegradation of keratin by microorganisms possessing keratinase activity can be used as an alternative tool to prevent environmental pollution. For practical use of keratinase, its physicochemical properties should be investigated in detail. In this study, we investigated characteristics of keratinase produced by Xanthomonas sp. P5 which is isolated from rhizospheric soil of soybean. The level of keratinase produced by the strain P5 increased with time and reached its maximum (10.6 U/ml) at 3 days. The production of soluble protein had the same tendency as the production of keratinase. Optimal temperature and pH of keratinase were $40^{\circ}C-45^{\circ}C$ and pH 9, respectively. The enzyme showed broad temperature and pH stabilities. Thermostability profile showed that the enzyme retained 94.6%-100% of the original activity after 1 h treatment at $10^{\circ}C-40^{\circ}C$. After treatment for 1 h at pH 6-10, 89.2%-100% of the activity was remained. At pH 11, 71.6% of the original activity was retained after 1 h treatment. Although the strain P5 did not degrade human hair, it degraded duck feather and chicken feather. These results indicate that keratinase from Xanthomonas sp. P5 could be not only used to upgrade the nutritional value of feather hydrolysate but also useful in situ biodegradation of feather.

• 한국토양비료학회지
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• 제29권1호
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• pp.67-73
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• 1996

식물(植物) 생육촉진(生育促進) 유용미생물(有用微生物)을 지리산 일대의 침엽수와 활엽수 밑의 부엽토(腐葉土)에서 선발하고, 고추묘에 접종하여 묘의 생장에 미치는 효과를 조사한 결과는 다음과 같다. 1. 분리된 8종의 균주를 동정한 결과 Micrococcus sp., Bacillus subtilis, Enterobacter agglomerans, Bacillus megaterium, Pseudomonas putida, Pseudomonas fluorescens, Xanthomonas maltophilia, Staphylococcus xylosus등 8종의 균주가 동정되었다. 2. 8종의 혼합균주 처리구의 고추묘의 초장(草長)은 무처리구에 비해 처리 10일 이후, 엽수(葉數)는 44일 이후부터 생육이 크게 진전되었다.

• 한국환경과학회지
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• 제19권10호
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• pp.1307-1314
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• 2010

This study was conducted to isolate and characterize a novel feather-degrading bacterium producing keratinase activity. A strain K9 was isolated from soil at poultry farm and identified as Xanthomonas sp. K9 by phenotypic characters and 16S rRNA gene analysis. The cultural conditions for the keratinase production were 0.3% fructose, 0.1% gelatin, 0.04% $K_2HPO_4$, 0.06% $KH_2PO_4$, 0.05% NaCl and 0.01% $FeSO_4$ with an initial pH 8.0 at $30^{\circ}C$ and 200 rpm. In an optimized medium containing 0.1% chicken feather, production yield of keratinase was approximately 8-fold higher than the yield in basal medium. The strain K9 effectively degraded chicken feather meal (67%) and duck feather (54%), whereas human nail and human hair showed relatively low degradation rates (13-22%). Total free amino acid concentration in the cell-free supernatant was about 25.799 mg/l. Feather hydrolysate produced by the strain K9 stimulated growth of red pepper, indicating Xanthomonas sp. K9 could be not only used to increase the nutritional value of chicken feather but also a potential candidate for the development of natural fertilizer applicable to crop plant soil.

• The Plant Pathology Journal
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• 제37권2호
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• pp.173-181
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• 2021

The genus Streptomyces demonstrates enormous promise in promoting plant growth and protecting plants against various pathogens. Single and consortium treatments of two selected Streptomyces strains (Streptomyces shenzhenensis TKSC3 and Streptomyces sp. SS8) were evaluated for their growth-promoting potential on rice, and biocontrol efficiency through induced systemic resistance (ISR) mediation against Xanthomonas oryzae pv. oryzicola (Xoc), the causal agent of rice bacterial leaf streak (BLS) disease. Seed bacterization by Streptomyces strains improved seed germination and vigor, relative to the untreated seed. Under greenhouse conditions, seed bacterization with consortium treatment TKSC3 + SS8 increased seed germination, root length, and dry weight by 20%, 23%, and 33%, respectively. Single and consortium Streptomyces treatments also successfully suppressed Xoc infection. The result was consistent with defense-related enzyme quantification wherein single and consortium Streptomyces treatments increased peroxidase (POX), polyphenol oxidase, phenylalanine ammonia-lyase, and β,1-3 glucanase (GLU) accumulation compared to untreated plant. Within all Streptomyces treatments, consortium treatment TKSC3 + SS8 showed the highest disease suppression efficiency (81.02%) and the lowest area under the disease progress curve value (95.79), making it the best to control BLS disease. Consortium treatment TKSC3 + SS8 induced the highest POX and GLU enzyme activities at 114.32 µmol/min/mg protein and 260.32 abs/min/mg protein, respectively, with both enzymes responsible for plant cell wall reinforcement and resistant interaction. Our results revealed that in addition to promoting plant growth, these Streptomyces strains also mediated ISR in rice plants, thereby, ensuring protection from BLS disease.

• Applied Biological Chemistry
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• 제39권5호
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• pp.349-354
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• 1996

생물학적 난분해성 물질인 폴리비닐 알콜(PVA : Polyvinyl alcohol)을 탄소원 및 에너지원으로 이용하는 Xanthomonas campestris J2Y로부터 PVA oxidase를 생산하여 정제하기 위하여 PVA가 탄소원으로 첨가된 배지에서 진탕배양한 배양액을 원심분리한 후 상등액을 10 mM phosphate buffer(pH 7.5)로 평형시킨 DEAE -cellulose를 통과시켜 얻은 분획을 사용하여 DEAE-cellulose와 Sephadex G-150을 이용한 Gel filtration을 통하여 PVA oxidase를 정제하였다. 정제된 PVA oxidase는 polyacrylamide gel 전기영동으로 단일밴드로 확인되었으며 SDS-polyacrylamide gel 전기영동과 Sephadex G-150 column chromatography를 통해 측정한 결과 55,000 daltons 이었다. PVA oxidase의 최적 pH는 7이고 최적온도는 $37^{\circ}C$였다. 열 안정성은 $50^{\circ}C$까지는 70% 이상의 안정성을 나타내었고, pH에 대한 안정성은 5-11에서 비교적 안정하였다. 금속이온에 대한 영향은 $Ag^{2+},\;Hg^{2+},\;Sn^{2+}$ 등에서는 아주 강한 저해를 받았고, $Co^{2+},\;Fe^{2+},\;Zn^{2+},\;Pb^{2+}$에서는 50% 정도의 저해를 받았다. 반면에 $Mn^{2+},\;Cu^{2+}$는 효소활성을 증가시켰다. PVA에 정제 PVA oxidase의 Km치는 $7.04{\times}10\;^2mmol/{\ell}$이었다.

• Journal of Microbiology and Biotechnology
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• 제20권3호
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• pp.494-500
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• 2010

Bacterial blight, an important and potentially destructive bacterial disease in rice, is caused by Xanthomonas oryzae. Recently, this organism has developed resistance to available antibiotics, prompting scientists to find a suitable alternative. This study focused on secondary metabolites of Phomopsis longicolla to target X. oryzae. Five bioactive compounds were isolated by activity-guided fractionation from ethyl acetate extracts of mycelia and were identified by LC/MS and NMR spectroscopy as dicerandrol A, dicerandrol B, dicerandrol C, deacetylphomoxanthone B, and fusaristatin A. This is the first time fusaristatin A has been isolated from Phomopsis sp. Deacetylphomoxanthone B showed a higher antibacterial effect against X. oryzae KACC 10331 than the positive control (2,4-diacetyphloroglucinol). Dicerandrol A also showed high antimicrobial activity against Gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis) and yeast (Candida albicans). In addition, high production yields of these compounds were obtained at the stationary and death phases.

• 한국균학회지
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• 제20권2호
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• pp.109-117
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• 1992

운동성을 띠는 5가지 부생균과 1종류의 식물병원세균으로 Agrobacterium radiobacter, Bacillus subtilis, B. polymyxa, Pseudomonas aeruginosa, P. fluorescens 및 Xanthomonas malvacearum을 공시하여 이들 세균이 Cochliobolus sativus 분생포자, Fusarium oxysporum f. sp. ciceri의 후막포자, Macrophomina phaseolina의 균핵 및 Phytophthora drechsleri f. sp. cajani 난포자의 분비물에 미치는 화학주성을 서로 다른 무생물적 조건하에서 실험하였다. 균의 분비물의 농도와 세균세포의 끌리는 유인사이에는 정상관$(r=0.76{\sim}0.89)$이 있었다. 유사한 결과로서 화학주성반응과 배양간격에서도 통계적인 정상관이 있다$(r=0.82{\sim}0.95)$. 세균의 화학주성반응은 온도와 pH에 크게 영향을 받는다. 최적 화학주성을 나타내는 온도로서 A. radiobacter는 $25^{\circ}C$, B. polymyxa, P. aerugionosa, p. fluorescens and X. madracearum은 $30^{\circ}C$이었고, B. subtilis는 $35^{\circ}C$가 최적이었다. 최대 화학주성을 나타내는 분비물의 주성은 pH7이고 pH3과 11에서는 buffer와 같았다. 시험용 모세관에 유인물질이나 buffer 중 어느 종류가 채워져도 유인물질이 있는 시험관에 연결되면 세균은 주성이 나타난다는 것이 증명되었다.