• The Plant Pathology Journal
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• v.36 no.2
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• pp.185-191
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• 2020

Streptomyces griseus S4-7, a well-characterized keystone taxon among strawberry microbial communities, shows exceptional disease-preventing ability. The whole-genome sequence, functional genes, and bioactive secondary metabolites of the strain have been described in previous studies. However, proteomics studies of not only the S4-7 strain, but also the Streptomyces genus as a whole, remain limited to date. Therefore, in the present study, we created a proteomics reference map for S. griseus S4-7. Additionally, analysis of differentially expressed proteins was performed against a wblE2 mutant, which was deficient in spore chain development and did not express an antifungal activity-regulatory transcription factor. We believe that our data provide a foundation for further in-depth studies of functional keystone taxa of the phytobiome and elucidation of the mechanisms underlying plant-microbe interactions, especially those involving the Streptomyces genus.

• Journal of Applied Biological Chemistry
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• v.43 no.3
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• pp.136-140
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• 2000

A novel 6-deoxyhexose biosynthetic gene cluster different from the one for the biosynthesis of streptomycin was isolated from Streptomyces griseus using specifically designed PCR primers to compare the sequence of known dTDP-glucose synthase genes. We cloned a 5.8-kb DNA from Streptomyces griseus ATCC10137, which contained the 4-ketoreductase homologue (grsB), dTDP-glucose synthase (grsD), and dTDP-glucose 4, 6-dehydratase (grsE) genes. Escherichia coli cultures containing plasmid of the PCR product which encoded the grsE region under the controUed T7 promoter were able to catalyze the formation of dTDP-4-keto-6-deoxy-D-glucose from TDP-glucose. The enzyme showed high substrate specificity, being specific to only dTDP-glucose that is known to be incorporated into secondary metabolites such as antibiotics.

• The Plant Pathology Journal
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• v.28 no.3
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• pp.282-289
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• 2012

The root rot of pepper (Capsicum annuum L.) caused by Phytophthora capsici is one of the most important diseases affecting this crop worldwide. This work presents the evaluation of the capacity of Streptomyces griseus H7602 to protect pepper plants against Phytophthora capsici and establishes its role as a biocontrol agent. In this study, we isolated an actinomycete strain H7602 from rhizosphere soil, identified it as Streptomyces griseus by 16S rRNA analysis and demonstrated its antifungal activity against various plant pathogens including P. capsici. H7602 produced lytic emzymes such as chitinase, ${\beta}$-1,3-glucanase, lipase and protease. In addition, crude extract from H7602 also exhibited destructive activity toward P. capsici hyphae. In the pot trial, results showed the protective effect of H7602 against pepper from P. capsici. Application of H7602 culture suspension reduced 47.35% of root mortality and enhanced growth of pepper plants for 56.37% in fresh root and 17.56% g in fresh shoot as compared to control, resulting in greater protection to pepper plants against P. capsici infestation. Additionally, the enzymatic activities, chitinase and ${\beta}$-1,3-glucanase, were higher in rhizosphere soil and roots of pepper plants treated with H7602 than other treated plants. Therefore, our results indicated a clear potential of S. griseus H7602 to be used for biocontrol of root rot disease caused by P. capsici in pepper.

• Proceedings of the Microbiological Society of Korea Conference
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• 2004.05a
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• pp.51-51
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• 2004

• Animal Systematics, Evolution and Diversity
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• v.9 no.2
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• pp.281-292
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• 1993

Five species of lsotomidae from North Korea, including four new species lsotomurus griseus nsp., I. myohyangsanus nsp., Isotoma grana nsp., I. agrana n. sp. and one new record for North Korea, Folsomia octoculata Handschin, 1925 are described and discussed. The Korean Isotomidae, therefore, come to list 19 species in 6 genera including 15 species in six genera from South Korea.

• The Korean Journal of Zoology
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• v.16 no.4
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• pp.211-217
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• 1973

Mitomycin C, chemically reactive antibiotics derived from Streptomyces caespitosus, was introduced to Chinese hamster, Cricetulus griseus, (2n=22) cells (22Emb. ♀5PSP ♂, to carry out an analysis of the chromosome aberration. It was found that regions 5 and 7 of chromosomes 1 and 2, and secondary constriction of chromosome X showed the most striking effect of Mitomycin C. The relationship between Mitomycin C and secondary contriction was discussed.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2002.10a
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• pp.94-94
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• 2002

• Microbiology and Biotechnology Letters
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• v.20 no.3
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• pp.295-301
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• 1992

An alkaline protease producing microorganism was isolated from soil and identified as Streptomyces griseus HC-1141. The optimum pH and temperature for the purified enzyme activity were 8.0 and $60^{\circ}C$, respectively. The enzyme was relatively stable in the pH range of 7.0-9.0 and at the temperature below $60^{\circ}C$. The activity of purified enzyme was inhibited by $Hg^{2+}$, $Cu^{2+}$, $Zn^{2+}$, $Ba^{2+}$ and $Fe^{2+}$, whereas activated by $Mn^{2+}$ and $Ca^{2+}$. $\varepsilon$-Amino caproic acid, 2,4-dinitrophenol and iodine did not show inhibitory effect on the activity of alkaline protease, but p-chloromercuribenzoic acid, ethylendiaminetetraacetic acid showed inhibitory effect on the enzyme activity. These result suggested that the protease was metalloenzyme, and require a reactive SH group for the activity. The reaction of this enzyme follows typical Michaelis-Menten kinetics with the $K_m$ value of $2.229{\times}10^{-4}$M and the $V_{max}$ of $46.08 {\mu}$g/min for casein. The activation energy for the alkaline protease calculated by Arrhenius equation was 3.643 kcal/mol. This enzyme hydrolyzed casein more rapidly than the hemoglobin and egg albumin.

• Microbiology and Biotechnology Letters
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• v.30 no.3
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• pp.235-240
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• 2002

Streptomycetes is a group of Gram-positive soil bacteria that growas a branching vegetative mycelium leading to the formation of spores, and display a physiological differenti-ation related to the synthesis of many secondary metabolites including antibiotics. Their complex life cycle and multicellular differentiation require various levels of regulation and types of signal transduction systems including eukaryotic-type serine/threonine protein kinases and prokaryotic-type histidine/aspartic acid protein kinases. Akt kinase that was found in cells is a sorine/threonine kinase controlling signal pathway for multi-tude of important cellular events. The activation or inactivation of Akt kinase in the cell is one of the critical regulatory points to deliver cell proliferation, differentiation, survival or apoptosis signal. To find the regula-tory protein homologous to Akt in Streptomyces, the fluorescien-labeled synthetic peptide (FITC-TRRSR-TESIT) was designed from the consensus sequence of target proteins for Akt kinase. From the difference of the mobility between the nonphosphorylated and phosphorylated synthetic peptides on Agarose gel electro-phoresis, the Akt-phosphorylating activity was monitored. The cell-free extract prepared from Streptomyces griseus IFO 13350 and the Akt homologous protein was purified by ammonium sulfate fractionation and many steps of column chromatographies such as, DEAE-Sepharose, Mono Q, Resource Phenyl-Soporose and Gel permeation column chromatographies. As a result, the protein phosphorylating the fluorescien-labeled Akt substrate was identified and it's molecular weight was estimated as 39 kDa on SDS-PAGE.

• 한국균학회소식:학술대회논문집
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• 2015.05a
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• pp.54-54
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• 2015

Crops lack genetic resistance to most necrotrophic soil-borne pathogens and parasitic nematodes that are ubiquitous in agroecosystems worldwide. To overcome this disadvantage, plants recruit and nurture specific group of antagonistic microorganisms from the soil microbiome to defend their roots against pathogens and other pests. The best example of this microbe-based defense of roots is observed in disease-suppressive soils in which the suppressiveness is induced by continuously growing crops that are susceptible to a pathogen. Suppressive soils occur globally yet the microbial basis of most is still poorly described. Fusarium wilt, caused by Fusarium oxysporum f. sp. fragariae is a major disease of strawberry and is naturally suppressed in Korean fields that have undergone continuous strawberry monoculture. Here we show that members of the genus Streptomyces are the specific bacterial components of the microbiome responsible for the suppressiveness that controls Fusarium wilt of strawberry. Furthermore, genome sequencing revealed that Streptomyces griseus, which produces a novel thiopetide antibiotic, is the principal species involved in the suppressiveness. Finally, chemical-genetic studies demonstrated that S. griseus antagonizes F. oxysporum by interfering with fungal cell wall synthesis. An attack by F. oxysporum initiates a defensive "cry for help" by strawberry root and the mustering of microbial defenses led by Streptomyces. These results provide a model for future studies to elucidate the basis of microbially-based defense systems and soil suppressiveness from the field to the molecular level.