• Journal of Microbiology
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• v.33 no.4
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• pp.344-349
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• 1995

The alkalophilic bacterium, Xanthomonas sp. JK311, producing extracellular proteases, was isolated from soil. Xanthomonas sp. JK311 produced five extracellular proteases that are all metalloproteases. Four of them were resistant against 1% SDS. Chromosomal DNA of the Xanthomonas sp. JK311 was digested with BamHI and cloned into PUC19. Among E. coli strain HB101 transformants, a clone secreting the proteases was screened through halo formation on skim-milk agar plate and by Southern blot analysis. It had the recombinant plasmid pXEP-1 containing the 7.5 kb-BamHI DNA fragment and produced three extacellular proteases. Their protease properties corresponded to those of Xanthomonas sp. JK311.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.1
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• pp.53-57
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• 1996

Xanthomonas sp. EPS-1으로부터 생산된 다당류 EPS-1 용액의 농도가 0.04(g/dl)일 때, 비점도는 0.137, 환원 점도는 3.425, 상대점도는 1.137, 고유점도는 3.209임을 알 수 있었다. 겉보기 점도는 온도상슴에 따라 낮아졌으나 다시 온도를 증가하였을때는 서서히 증가하였다. 열처리 후에도 물성은 거의 변화지 않았으며, 응집성은 좋지 않았으나 locust bean gum과의 혼합효과는 우수하였다.

• Microbiology and Biotechnology Letters
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• v.23 no.2
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• pp.145-149
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• 1995

For the purpose of developing a new biodegradable detergent, we have isolated a gene encoding wide-range temperature applicable alkaline protease from Xanthomonas sp. YL-37 (Lee et al., 1994, Kor. J. Appl. Microbiol. Biotechnol.). An alkaline protease gene was isolated from the gene bank that was prepared from the chromosomal DNA of Xanthomonas sp. YL-37. From the results of agarose gel electrophoresis and a restriction enzyme mapping, a 2.7 kb DNA fragment containing the alkaline protease gene was inserted in the plasmid pUC9. Extracellular activity of a clone having alkaline protease gene was detected on SDS-polyacrylamide gel with activity staining assay. The molecular weight of alkaline protease was determined to be about 64 kDa from 11% SDS-PAGE analysis. Alkaline protease activity, produced from E. coli which harboring the plasmid, showed no difference at reaction temperature 20, 30 and 40$\circ$C, respectively. This result showed that alkaline protease produced from E. coli harboring the plasmid was apparently the same as that of Xanthomonas sp. YL-37.

• Microbiology and Biotechnology Letters
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• v.22 no.5
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• pp.515-521
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• 1994

A bacterial strain, which showed the high protease activity at low temperature and the high tolerance for the surfactant, was isolated from soil and identified as Xanthomonas sp. YL-37. The optimal temperature, initial pH, and cultivation time for the production of the alkaline protease by Xanthomonas sp. YL-37 were 20$\circC , 11.0, and 84 hours, respectively. In the jar fermenter culture of Xanthomonas sp. YL-37, the alkaline protease activity was about 15,000 DU/ml/-broth after cultivating for 108 hours. The optimal pH and temperature for the protease activity were 70$\circC and 11.0, respectively. The protease was relatively stable at the pH range of 7.0~12.0 and at the temperatures below 50$\circC . The protease activity at 20$\circC was about the level of 40% of its activity at 70$\circC . The enzyme was suggested as a serine protease because the enzyme activity was inhibited by phenylmethane sulfonyl fluoride, a serine modifier.

• Applied Biological Chemistry
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• v.35 no.1
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• pp.30-35
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• 1992

Two strains J2W and J2Y which were isolated from soil can utilize polyvinyl alcohol(PVA) as a sole carbon source. PVA was utilized symbiotically by the mixed culture of these two strains which could not utilize PVA in each respective pure culture. Effect of degree of PVA polymerization on the its utilization was examed, and there was remarkable difference among three kind of PVA(PVA 500, 1500 and 2000). The reconstruction of there two strains was carried out with other symbionts Pseudomonas sp. PW and Pseudomonas sp. G5Y which were able to utilize PVA. PVA utilization occured in each remixed culture of J2Y strain with Pseudomonas sp. PW J2W strain with Pseudomonas sp. G5Y, respectively. Identification of bacteria was based on morphological and biological chatacteristics, J2W and J2Y strain were similar to a strain of Pseudomonas pseudimallei and Xanthomonas campestris, respectively.

• Applied Biological Chemistry
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• v.41 no.2
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• pp.125-129
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• 1998

Xanthomonas sp. isolated from soil exhibited cell wall lytic activity of Candida albicans and secreted chitinase in chitin media. Especially, the chitinase activity was induced by chitin and reached a maximum level at 3 days culture in chitin media. We constructed genomic library of Xanthomonas sp. using cosmid vector in E. coli. Oligonucleotide probe was synthesized from the consensus sequence corresponding to chitinase active site, which was derived from the comparison of amino acid sequences of bacterial chitinase genes. Using this oligonucleotide probe, we screened the genomic library. By restriction enzyme mapping of the positive clones, we identified 4 independent clones which may contain the chitinase gene. One of the clones, named pXCH1 (1.2 kb insert), was further analyzed. Northern blot analysis indicated that is transcripts, 1 kb and 0.8 kb, were induced by chitin. When the cloned gene was induced by IPTG in E.coli cell, chitinase activity which was secreted onto culture media was not observed. However, when the cell was disrupted by using sonicator and then centrifuged, the supernatant exhibited chitinase activity. SDS-PAGE of the supernatant indicated that about 35 kDa protein was induced by IPTG. From these results, it was concluded that the cloned DNA was one of the chitinase genes of Xanthomonas sp.

• Korean Journal of Microbiology
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• v.52 no.2
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• pp.212-219
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• 2016

Forty-nine pigments were extracted from the collections of 106 pigment producing bacteria from the plant rhizosphere soil. Antibacterial activity test was performed in the subjects of the extracted pigments with plant pathogenic bacteria including Xanthomonas axonopodis and Xanthomonas campestris, and with plant pathogenic fungi including Botrytis cinerea, Colletotrichum acutatum, and Fusarium oxysporum. The yellow pigment by Chryseobacterium sp. RBR9 and the red pigment by of Methylobacterium sp. RI13 showed the antibacterial activities against Xanthomonas axonopodis and Xanthomonas campestris. The violet pigment by Collimonas sp. DEC-B5 showed the antibacterial activity as well as the antifungal activities against Botrytis cinerea and Fusarium oxysporum. Especially, the violet pigment inhibited the growth of Botrytis cinerea more than 65% at MIC $20{\mu}M$. Upon the HPLC analysis result for the isolation of pigment with antifungal activity, violacein (91.6%) and deoxyviolacein (8.4%) were isolated for the pigment by Collimonas sp. DEC-B5. The production amount of the pigment was increased more than 10 times higher when D-mannitol 1.5% and yeast extract 0.2% were added as the nitrogen source to SCB medium. This study suggests that produced violacein by Collimonas sp. DEC-B5 will be effective to control strawberry gray-mold rot fungi by its preventive activity.

• Plant Disease and Agriculture
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• v.5 no.1
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• pp.41-45
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• 1999

Bacterial population densities on soybean pods from Chungnam province ranges 105~106 CFU/$\textrm{cm}^2$, whereas those of bacteria causing sprout rot ranged 0~103 CFU/$\textrm{cm}^2$. Erwinia chrysanthemi, Xanthomonas campestris pv. glycines, Staphylococcus sp., and Micrococcus sp. were identified as pathogenic bacteria causing soybean sprout rot. The population density of X. campestris pv. glycines was higher than those of other bacteria.

• Microbiology and Biotechnology Letters
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• v.23 no.3
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• pp.269-274
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• 1995

For the screening of a new functional exopolysaccharide, sugar composition and rheological properties of exopolysaccharide produced from Xanthomonas sp. EPS-1 were investigated. The average molecular weight of exopolysaccharide was determined to be approximately 2.l $\times$ 10$^{6}$ dalton. The new exopolysaccharide EPS-1 was composed of mannose, glucose, galactose and gluco- samine. IR analysis showed that the exopolysaccharide EPS-1 was assumed to be polymer with carbohydrates. NMR analysis showed that exopolysaccharide EPS-1 was presumed to be 4 units of sugar and trace of CH$_{3}$ group. Exopolysaccharide EPS-1 solution showed a characteristic of non-Newtonian fluid properties. At the concentration of 1.0%, the consistency index and the flow behavior index were shown at 10.8352 poise-sec and 0.4419, respectively. All dispersions were pseudoplastic fluids described accurately by Power-law model. Exopolysaccharide EPS-1 was highly viscous at low concentration, with good stability over a wide range of pH 5 to 13. The excellent compatibility of exopolysaccharide EPS-1 was represented with salts such as sodium chloride.

• Korean Journal of Environmental Agriculture
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• v.40 no.1
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• pp.20-32
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• 2021

BACKGROUND: Bacterial shot hole of stone fruits is a seriuos plant disease caused by Xanthomonas arboricola pv. pruni (Xap). Techniques to control the disease are required. In this study, microorganisms with antibacterial activity were isolated to develop as a microbial agent against the bacterial shot hole. METHODS AND RESULTS: An isolate with the strongest activity among the isolates was identified as Streptomyces avidinii based on 16S rRNA gene sequence analysis and designated Streptomyces sp. J46. J46 showed suppression of bacterial leaf spot with a control value of 90% at 10 times-diluted cell free supernatant. To investigate antibacterial metabolites produced by J46, the supernatant of J46 was extracted with organic solvents, and the extracts were subjected to chromatography works. Antibacterial metabolites were not extractable with organic solvents. Both reverse and normal phase techniques were not successful because the metabolites were extremely water soluble. The antibacterial metabolites were not volatiles but protein compounds based on hydrolysis enzyme treatment. CONCLUSION: Our study suggests that Streptomyces sp. J46 may be a potential as an microbial agent against bacterial shot hole. Further study to identify the metabolites is required in more detail.