• KSBB Journal
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• v.25 no.2
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• pp.167-172
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• 2010

Streptomyces scabiei producing phytotoxin called thaxtomin, which cause scab disease on economically important crops such as potato. For molecular genetics study of S. scabiei an effective transformation method was established based on conjugal transfer from Escherichia coli ET12567 (pUZ8002) using a phiC31-derived integration vector, pSET152, containing oriT and attP fragments. The high frequency was obtained on MS medium containing 50 mM $MgCl_2$. In addition, the sequence and location of the chromosomal integration attB site of S. scabiei was identified for the first time in the strains producing thaxtomin by the southern blot analysis of exconjugants and the sequencing of plasmid containing DNA flanking the insertion sites from exconjugant chromosome. Similar to the case of Streptomyces species, a single phiC31 attB site of S. scabiei is present within an ORF encoding a pirin-homolog.

• Korean Journal of Plant Resources
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• v.24 no.5
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• pp.622-627
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• 2011

This study was designed to investigate the possible role of 10 green manure crop extracts in antimicrobial activity against potato common scab (Streptomyces scabiei). Ten green manure crops were extracted with hexane, ether, ethylacetate, methanol and water. The DPPH radical scavenging activity of ether, methanol and water was higher than those of hexane and ethylacetate fractions. The fractions of methanol, ethylacetate, ether and water showed antimicrobial activity against Streptomyces scabiei from the concentration of 0.25 mg/mL. Methanol fraction of Sorghum showed the highest antimicrobial activity against this microorganism. This result suggests the sorghum extract was the best as good green manure crop with antimicrobial activity against Streptomyces scabiei.

• Journal of Microbiology
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• v.40 no.2
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• pp.178-181
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• 2002

Streptomycete isolator strain M0137 showed cytotoxic effect on THP-1 cells. One of the purified substances produced from the strain was identified as nonadecanoic acid. Morphological and physiological properties, phylogenetic analysis, and genomic fingerprinting of strain M0137 were determined. Strain M0137 showed a high similarity with Streptomyces scabiei, phenotypically and phylogenetically. In contrast, genomic fingerprinting and G+C content analysis revealed that strain M0137 could be distinguished from S. scabiei ATCC49173$\^$T/. We propose to name strain M0137 as Streptomyces scabiei Subsp.

• Journal of Environmental Science International
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• v.32 no.11
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• pp.777-788
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• 2023

Potato common scab disease is caused by pathogens belonging to Streptomyces spp. and results in a serious yield loss worldwide. Despite decades of research aimed at disease management, a definitive control method remains undiscovered. This study aims to explore the correlation between the C/N ratio and urea application with potato common scab pathogen dynamics and disease severity. We applied sawdust with a high C/N ratio and urea into the soil prior to potato cropping, both in pot and field experiments. Disease severity assessments and quantification of the TxtB gene were conducted at the harvest stage. Furthermore, culture experiments were performed to assess the direct impact of urea on the pathogen. Our findings revealed that higher disease severity was correlated with a high C/N ratio application and pathogenic gene quantity. Urea exhibited a direct influence on S. scabiei activity, reducing the disease severity in pot experiments. However, the effects of urea application on disease suppression in the conductive field were inconclusive. Although the results of urea application experiments displayed inconsistencies between pot and field trials, urea worked as the control to suppress S. scabiei activity. Further investigations are needed under various field conditions to confirm these findings.

• The Plant Pathology Journal
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• v.20 no.2
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• pp.115-126
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• 2004

The actinomycete strain PK-A41 was isolated from a soil sample from pepper fields in Ko-yang, Korea. The strain PK-A41 inhibited the mycelial growth of some plant pathogenic fungi and oomycete, Alternaria mali, Colletotrichum orbiculare, Fusarium oxysporum f.sp. lycopersici, Magnaporthe grisea, Rhizoctonia solani, and Phytophthora capsici. The presence of LL-diaminopi-melic acid in the cell wall extract and the nucleotide sequence of the 16S rDNA region of the strain PK-A41 was assigned to Streptomyces scabiei. Further morpho-logical, biochemical, and pathological analyses also confirmed the strain PK-A41 to be S. scabiei, which is pathogenic to potato tubers. The maximum antibiotic production of the strain PK-A41 was achieved when grown on the glycerol peptone broth (GPB) medium for 9 days.

• Journal of Microbiology
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• v.40 no.4
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• pp.331-334
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• 2002

The substance 0116p, which exhibits cytotoxicity against human macrophage cell line THP-1, was isolated from a mycelial extract of Streptomyces scabiei subsp. chosunensis M0137. The cytotoxic substance was purified by Diaion-HP2O adsorption, solvent extraction, Sephadex LH-20 column chromatography, and silica-gel column chromatography. The molecular formula is C$\_$19/H$\_$38/O$\_$2/ (MW301.10) based on elemental and spectrometric analysis. It was identified as nonadecanoic acid by NMR spectral data. It exhibits cytotoxic activities in various human cancer cell lines, including A549, SK-OV-3, SK-MEL-2 and HCT-15. In addition, 0116p also inhibits IL-12 production in lipopolysaccharide-activated macrophages.

• The Plant Pathology Journal
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• v.20 no.2
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• pp.110-114
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• 2004

Through in vitro screening for biocontrol agents (BCAs) against Streptomyces scabiei causing potato (Solanum tuberosum) common scab, 19 streptomycete and 17 fungal isolates with antagonistic activity were selected as BCA candidates. For the selection of BCA candidates which are highly resistant to 10 kinds of antibiotics or pesticides, chemical susceptibility testing was initially performed in vitro. A remarkable degree of variation in susceptibility to antibiotics or pesticides was observed among the isolates tested. Streptomycete A020645 isolate was highly resistant to all the tested chemicals except neomycin up to 5,000 ppm. On the other hand, out of 36 antagonistic microbes subjected to in vivo pot tests using cultivar Daejima, four streptomycete isolates namely, A020645, A010321, A010564, and A020973, showed high antagonistic activity with >60% and 55% control value, respectively, and high chemical resistance to 10 kinds of chemicals. Therefore, these isolates were selected as potential BCAs for the control of potato common scab.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.334.1-334.1
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• 2002

Streptomyces scabiei subsp. chosunensis M0137. nonadecanoic acid producer. showed the highest protease activity when grown in OSY medium (oatmeal 1.5%, soybean meal 2%, dried yeast 1 %) supplemented with. glycerol (1 %) and CaCO3 (0.1 %). Two forms of protease(SS-1 and SS-2) were fractionated and purified through Ultrogel AcA 54 gel filtration and DEAE-sepharose CL-6B column chromatography. Both proteases were practically stable in the pH range of 6-10. The optimal pH for the activities of both protease 88-1 and 8S-2 were 7.5 and 8.0. respectively. (omitted)

• Applied Biological Chemistry
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• v.47 no.2
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• pp.164-169
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• 2004

In the course of our screening for biocontrol agent (BCA) against Streptomyces scabiei and S. turgidiscabies causing potato scab using 5,000 actinomtcete isolates, 9 antagonistic strains were selected as BCA candidates through in vitro and in vivo assay. An antagonistic strain, A020645 was highly resistant to some pesticides and antibiotics such as dazomet and mancozeb and showed high control value in vivo. Two bioactive compounds (compound A, B) were purified by anion exchange chromatography, solid phase (ODS) extraction, TLC and reverse phase HPLC. Their chemical structures are now thought to be nucleoside derivative as determined by $^1H-NMR$ data analysis. Their full chemical structures would be elucidated through $^{13}C-NMR$, HMQC and HMBC analyses. Further studies will be focused on fitness in soil and formulation of the BCA candidates.

• Journal of Microbiology and Biotechnology
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• v.25 no.8
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• pp.1265-1274
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• 2015

Secondary metabolite-based chemotaxonomic classification of Streptomyces (8 species, 14 strains) was performed using ultraperformance liquid chromatography-quadrupole-time-offlight-mass spectrometry with multivariate statistical analysis. Most strains were generally well separated by grouping under each species. In particular, S. rimosus was discriminated from the remaining sevens pecies (S. coelicolor, S. griseus, S. indigoferus, S. peucetius, S. rubrolavendulae, S. scabiei, and S. virginiae) in partial least squares discriminant analysis, and oxytetracycline and rimocidin were identified as S. rimosus-specific metabolites. S. rimosus also showed high antibacterial activity against Xanthomonas oryzae pv. oryzae, the pathogen responsible for rice bacterial blight. This study demonstrated that metabolite-based chemotaxonomic classification is an effective tool for distinguishing Streptomyces spp. and for determining their species-specific metabolites.