• Proceedings of the Korean Biophysical Society Conference
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• 2002.06b
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• pp.49-49
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• 2002

Mutants blocked at the earliest stages of morphological development in Streptomyces species are called bld mutants. We have cloned bldB gene ORF from Slividans. Genomic Southern blot analysis for main strains S.lividans, S.seoulensis, S.coelicolor A3(2), and S.griseus indicated that bldB gene is conserved in all main Streptomyces strains.(omitted)

• 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.

• Journal of Microbiology and Biotechnology
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• v.8 no.3
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• pp.280-283
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• 1998

We have cloned the RNA polymerase sigma-like factors from a wide range of actinomycetes by using specific primers with the polymerase chain reaction (PCR). The specific oligonucleotide primers were designed on the basis of amino acid sequences of conserved regions from HrdA, B, D of Streptomyces griseus as well as from the rpoD box of many eubacteria. The consensus sequences were from the rpoD box and helix-turn-helix motif involved in -35 recognition. The designed primers were successfully applied to amplify the DNA fragments of the hrd homolog genes from 8 different strains of actinomycetes which produce a wide variety of important antibiotics. The 480 bp of the DNA fragment was amplified from all 8 strains, and it was identified as a part of hrdA and hrdB as we designed. The deduced amino acid sequence of PCR-amplified DNA fragments were highly homologous to those of other known RNA polymerase sigma factors of S. griseus and Streptomyces aureofaciens. Therefore, this study with specifically designed primers will support rapid cloning of the RNA polymerase sigma factors which recognize different classes of promoters from actinomycetes, and it will also be helpful in understanding the relationship of promoters and sigma factors leading to heterogeneity of RNA polymerases in actinomycetes.

• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.896-900
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• 2006

Cytokinin has been known to act as a plant hormone to promote cell division and function in diverse processes in plant growth and development. Besides being produced in plants, it is also produced by various bacteria and fungi; however, its ecological significance is still unclear. In this report, we present an interesting finding that transzeatin riboside (tZR), a naturally occurring cytokinin compound, increased antibiotic production in many different streptomycetes, including Streptomyces coelicolor Ml3O, S. pristinaespiralis ATCC 25486, S. violaceoruber Tu22, S. anfibioticus ATCC l1891, and S. griseus IFO 13350. In vitro plate assays showed that the addition of 100 $\mu$M tZR increased the growth inhibition of Pseudomonas syringae pv. syringae, a plant pathogen, by S. griseus, a streptomycin producer. We suggest that cytokinin could act as a signaling molecule for antibiotic production in streptomycetes, a group of rhizosphere bacteria.

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2001.10a
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• pp.252-256
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• 2001

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.383-386
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• 2012

Streptomyces spp. were isolated from rhizosphere in fallow lands. The Streptomyces spp. were identified as Streptomyces griseus (MSS181), Streptomyces griseoaurantiacus (MSS269), Streptomyces microflavus (MSS275), Streptomyces herbaricolor (MSS276) based on 16S rRNA gene sequences. Afterwards, cucumber, pepper, tobacco and tomato were drenched with the isolates at early growth stages and plant growth such as height and dry weight of plants was measured. By treatment of Streptomyce spp., plant height of cucumber was increased by 16-29% compared to the control, But there were no statistically significant differences in dry weight. When the same isolates were treated on chili-pepper, plant height and dry weight of chili-pepper were increased respectively by 10-19% and 19-25% compared to the control. The dry weight of tobacco and tomato were increased by 44-73% and 65-165%, respectively compared to the control. When antifungal activities of the isolates were tested against plant pathogenic fungi, Streptomyces microflavus (MSS275) effectively inhibited the mycelial growth of Phytophthora capsici, Fusarium oxysporum, Rhizoctonia solani and Sclerotinia sclerotiorum.

• Microbiology and Biotechnology Letters
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• v.30 no.2
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• pp.105-110
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• 2002

The sequence of 3,221 nucleotides immediately adjacent to rpsA gene encoding 30S ribosomal protein S1 of Brevibacterium ammoniagenes was determined. A putative open reading frame (ORF) of 2,670 nucleotides for a polypeptide of 889 amino acid residues and a TAG stop codon was found, which is located at a distance of 723 nucleotides upstream from rpsA gene with same translational direction. The deduced amino acid sequence of the ORF was found to be highly homologous to the DNA polymerase I of Streptomyces griseus (75.48％), Rhodococcus sp. ATCC 15963 (56.69％), Mycobacterium tuberculosis (55.46％) and Mycobacterium leprae (53.99％). It was suggested that the predicted product of the ORF is a DNA polymerase I with three functional domains. Two domains of 5 → 3 exonuclease and DNA polymerase are highly conserved with other DNA polymerase I, but 3 → 5 exonuclease domain is less conserved.

• The Korean Journal of Zoology
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• v.17 no.1
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• pp.37-42
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• 1974

Comparative LDH isozyme studies on normal, malignant and virus-transformed derivatives of Chinese and Armenian hamsters were illustrated. With respect to LDH isozyme patterns, there were good indications that epithelial-like cells have varying levels of LDH-1-2-3 and -4, in addition to the "standard" LDH-5 band, which was exhibited by the majority of fibroblast-like cell lines.ell lines.

• Molecules and Cells
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• v.26 no.4
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• pp.362-367
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• 2008

We identified a 1,134-bp putative type III polyketide synthase from the sequence analysis of Streptomyces peucetius ATCC 27952, named Sp-RppA, which is characterized as 1,3,6,8-tetrahydroxynaphthalene synthase and shares 33% identity with SCO1206 from S. coelicolor A3(2) and 32% identity with RppA from S. griseus. The 1,3,6,8-tetrahydroxynaphthalene synthase is known to catalyze the sequential decarboxylative condensation, intramolecular cyclization, and aromatization of an oligoketide derived from five units of malonyl-CoA to give 1,3,6,8-tetrahydroxynaphthalene, which spontaneously oxidizes to form 2,5,7-trihydroxy-1,4-naphthoquinone (flaviolin). In this study, we report the in vivo expression and in vitro synthesis of flaviolin from purified gene product (Sp-RppA).

• Journal of Microbiology
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• v.33 no.4
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• pp.315-321
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• 1995

The relationship between morphological differentiation and production of trypsin-like protease (TLP_ in streptomycetes was studied. All the Streptomyces spp.In this study produced TLP just before the onset of aerial mycelium formation. Addition of TLP inhibitor, TLCK, to the top surface of colonies inhibited aerial mycelium formation as well as TLP inhibitor, TLCK, to the top surface of colonies inhibited aerial mycelium formation as well as TLP activity. Addition of 2% glucose to the Bennett agar medium repressed both the aerial mycelium formation and TLP production in S. abuvaviensis, S. coelicolor A3(2), S exfoliatus, S. microflavus, S. roseus, s. lavendulae, and S. rochei. However the addition of glucose did not affect S. limosus, S. felleus, S. griseus, S. phaechromogenes, and S. rimosus. The glucose repression on aerial mycelium formation and production of TLP was relieved by the addition of glucose anti-metabolite (methyl .alpha.-glucopyranoside). Therefore, it was concluded that TLP production is coordinately regulated with morphological differentiation and TLP activity is essential for morphological differentiation in streptomycetes. The proposed role of TLP is that TLP participates in the degradation of substrate mycelium protein for providing nutrient for aerial mycelial growth.