• 미생물학회지
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• 제45권4호
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• pp.397-403
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• 2009

이 연구는 해양 유래의 천연 항산화물질에 관한 연구로서 항산화물질 생산 해양 방선균은 제주연안 해수에서 분리되었다. 균주는 16S rRNA 염기서열, 전자현미경에 의한 형태학적, 생리, 생화학적 및 세포 지방산 분석을 기초로 동정되었다. 분리균주 ACT-1은 그람양성, 호기성, 비운동성, 기질균사체색이 red, 기중균사체 색이 gray계열 이었다. 세포지방산 분석결과 주요 지방산으로 $C_{15:0}$ anteiso (39.33%), $C_{16:1}$ cis 9 (11.96%), $C_{16:0}$ (13.08%)와 $C_{17:0}$ anteiso (10.99%)로 분석되었으며, 최종적으로 Streptomyces sp. ACT-1으로 동정되었다. Streptomyces sp. ACT-1 메탄올 추출물의 항산화활성은 DPPH (1,1-diphenyl-2-picrylhydrazyl), hydroxyl, alkyl radical 소거활성을 ESR (electron spin resonance) spectrometer를 이용하여 측정되었다. SBME-1 (Streptomyces broth methanol extract)의 DPPH 라디컬 소거활성은 $1,000{\mu}g$/ml 농도에서 67%, Hydroxyl radical 소거활성은 $500{\mu}g$/ml에서 84%, Alkyl radical 소거활성은 $1,000{\mu}g$/ml 농도에서 71%를 보였다.

• 한국해양바이오학회지
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• 제9권2호
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• pp.49-57
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• 2017

We isolated marine bacterium, isolate DG-2 which produces the antibiotics against MRSA (methicillin-resistant Staphylococcus aureus). This isolate DG-2 was examined by its morphological, biochemical properties, and 16S rRNA sequencing analysis. And then, isolate DG-2 was identified to the genus Streptomyces. Therefore, this isolate was designated as Streptomyces sp. DG-2. Streptomyces sp. DG-2 grew relatively well at $25^{\circ}C$, pH 7.0, and NaCl 1.0%. For the pre-purification of the bioactive compounds, DG-2 was fermented in 30 L PPES-II medium, and the culture filtrates of DG-2 was extracted by ethyl acetate. The ethyl acetate extract of DG-2 showed the significant anti-MRSA and antibacterial activities.

• 한국미생물·생명공학회지
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• 제51권3호
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• pp.325-327
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• 2023

This paper presents the complete genome sequence of a novel marine actinomycete, Streptomyces sp. MMBL 11-1. The genome of Streptomyces sp. MMBL 11-1 was obtained through next-generation sequencing using the PacBio Sequel system and Illumina platform provided by Macrogen, Korea. The assembled genome consists of five contigs, with a total length of 8,496,900 bp and a G+C content of 71.6%. The genome harbors multiple biosynthetic gene clusters (BGCs) associated with producing microbial natural products (MNPs). The comprehensive genomic information of this type of strain will serve as a valuable resource for identifying other marine actinomycetes strains.

• 한국미생물·생명공학회지
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• 제49권3호
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• pp.356-366
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• 2021

Two marine actinobacterial isolates, RG3 and RG8, were identified using 16Sr DNA as Streptomyces althioticus RG3 and Streptomyces californicus RG8 and submitted to the database of genetic information with accession numbers MW661230 and MW661234, respectively; they were found to have emulsification indexes of 60 ± 2.5% and 53 ± 2.2%, respectively. The biosurfactants obtained were stable at a temperature of 35℃ for both strains; they were stable at 10% NaCl, in the case of S. althioticus RG3 and at 10-15% NaCl in the case of Str.californicus RG8; both strains produced the most biosurfactant when exposed to alkaline conditions. We characterized the biosurfactants, including features such as their chemical composition, using Fourier transform infrared spectroscopy analysis. The antimicrobial activity of the biosurfactant extracts was evaluated using the well diffusion method against Vibrio alginolyticus MK170250, Escherichia coli ATCC 8739, Pseudomonas aeruginosa ATCC 4027, and Staphylococcus aureus ATCC 25923. S. althioticus RG3 biosurfactants were found to have better antimicrobial activity than those of Str. californicus RG8, indicating that they may be used in pharmaceutical industries and in the manufacture of antifouling products.

• Journal of Microbiology and Biotechnology
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• 제17권8호
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• pp.1403-1406
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• 2007

An antiproliferative agent, streptochlorin, was isolated from the fermentation broth of a marine actinomycete isolated from marine sediment. Phylogenetic analysis of the 16S rRNA gene sequence indicated that the strain belongs to the genus Streptomyces. Bioactivity guided fractionation of the culture extract by solvent partitioning, ODS open flash chromatography, and reversed-phase HPLC gave a pure compound, streptochlorin. Its structure was elucidated by extensive 2D NMR and mass spectral analyses. Streptochlorin exhibited significant antiproliferative activity against human cultured cell lines.

• Journal of Microbiology and Biotechnology
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• 제11권4호
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• pp.663-667
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• 2001

A new secondary metabolite was isolated from the culture broth and mycelium of Streptomyces sp. collected from marine sediment. The structure of this compound was determined to be N-formylantimycic acid methyl ester, an acyclic derivative of antimycin, on the basis of combined chemical and spectral methods. The structure-activity relationship of antimycins is discussed.

• Fisheries and Aquatic Sciences
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• 제3권3_4호
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• pp.213-216
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• 2000

The marine actinomycetes are very interesting microorganisms for finding of new antibiotics, because they are inhabited in marine environmental conditions, such as salinity, organic material and low concentration of nutrient components that are differ from those of land. In this study, the actinomycetes producing antibiotics from sea waters and bottom deposit samples collected at east coast of Korea were investigated to invent new antibiotics. Nine actinomycetes strains having the antimicrobial activity of 431 actinomycetes were selected from sea waters and bottom deposit samples. Among the 9 strains, the strain having the highest antimicrobial activity was classified to Streptomyces sp. and named Streptomyces sp. NS 13239.

• 한국수산과학회지
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• 제45권1호
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• pp.25-29
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• 2012

Marine actinomycetes isolated from seaweed were screened for growth activation effects on the biodiesel-producing microalgae Dunaliella salina. Of the 98 actinomycetes studied, strain 288-11 isolated from the rhizosphere of Undaria pinnatifida showed potent growth activation. The strain was identified as Streptomyces anulatus based on 16S rDNA sequence analysis. The cell density increased up to 2.1-fold with the addition of 1 mg/mL of extract to the medium. To understand the effect of adding S. anulatus extract, the gross biochemical composition and fatty acids of D. salina were determined.

• Journal of Microbiology and Biotechnology
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• 제10권2호
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• pp.176-180
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• 2000

Three polyene macrolide antibiotics including two new compounds were isolated from the culture mycelia of a Streptomyces species. The structures of these metabollites were determined as elizabethin, a previously reported 28-membered macrolide and two analohs, using combined spectroscopic methods. These compounds exhibited antifungal activity and cytotoxicity against a juman leukemia cell.

• Fisheries and Aquatic Sciences
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• 제3권3_4호
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• pp.217-221
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• 2000

In previous study, marine actinomycetes producing the antibiotics were investigated to invent new antibiotics from east coast of Korea. The optimum growth conditions of Streptomyces sp. NS 13239 were $28^{\circ}C$, pH 7.0 and $3\%$ of NaCl concentration in various media. Streptomyces sp. NS 13239 showed strong antimicrobial activity against gram-positive bacteria, specially Methicillin resistant Staphylococcus aureus (MRSA), but just weak antimicrobial activity against yeasts and mold. On the other hand, it did not show antimicrobial activity against gram-negative bacteria. The optimum conditions for producing antibiotics were almost consistent with optimum growth conditions except carbon source and nitrogen source.