• 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.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.163-165
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• 1998

The use of synthetic pesticides in crop production, brings the possibility of a nonselective toxicity and accumulation of toxic compounds in the environment. As an alternative, bioactive compounds from actinomycetes can provide a rich source for biodegradable pesticides. A variety of biological activities such as antibacterial, antifungal, herbicidal, insecticidal and anticoccidial are associated with these microbial metabolites. Studies on the production of bioactive compounds from marine-derived actinomycetes have been very few, compared to the terrestrial actinomycetes. With their unique metabolic and physiological capabilities, the marine actinomycetes can be useful producers of novel metabolites.

• Ocean Science Journal
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• 제42권4호
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• pp.247-254
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• 2007

Marine bacteria, actionmycetes and fungal strains were isolated from continental slope sediment of the Bay of Bengal and studied for fatty acid profile to investigate their involvement in the benthic food-web. Fifteen different saturated and unsaturated fatty acids from bacterial isolates, 14 from actinomycetes and fungal isolates were detected. The total unsaturated fatty acids in bacterial isolates ranged from 11.85 to 37.26%, while the saturated fatty acid ranged between 42.34 and 80.74%. In actinomycetes isolates, total unsaturated fatty acids varied from 27.86 to 38.85% and saturated fatty acids ranged from 35.29 to 51.25%. In fungal isolates unsaturated fatty acids ranged between 44.62 and 65.52% while saturated FA ranged from 20.80 to 46.30%. The higher percentages of unsaturated fatty acids from the microbial isolates are helpful in anticipating the active participation in the benthic food-web of Bay of Bengal.

• 한국수산과학회지
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• 제26권4호
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• pp.305-311
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• 1993

본 연구에서는 생리활성물질을 생성하는 해양미생물을 분리하기 위하여 연근해역의 해면을 조사하였다. 해면 중의 미생물은 $1.2{\times}10{\sim}2.1{\times}10^3/g$ 범위에 있었고, 이들 중 방선균은 $0.01{\sim}0.5\%$(data 생략)로 나타났다. 분리된 미생물은 각각 배양하여 항균물질을 검토하였으며, 검토하던 중에 비교적 강한 항균물질을 생산하는 균주 No. 101을 분리, 선발하였다. 선발된 균의 특징은 sclerotia로 형태가 다양하였고, 다양한 배지에서 생육이 가능하였고, 기균사의 색깔은 회백색, 배면의 색깔은 주로 회백색에서 갈색으로 나타났으며, 젤라틴 액화능과 전분 분해능을 가지나 myo-inositol은 이용하지 못하였다. 이 균의 배양학적 특성은 최적 pH 및 온도가 $6.5{\sim}7.0$ 및 $30^{\circ}C$였으며, 탄소원으로는 starch가 30g/l, 질소원으로는 casamino acid 10g/l가 적합한 것으로 나타났다. 방선균 No. 101의 균체 및 균배양액의 추출물에 대한 항균 및 항진균성에서는 Staphylococcus aureus와 Bacillus subtilis에서 강한 항균력을, 효모와 곰팡이에 대하여는 낮은 항진균성을 나타내었다.

• 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.

• 한국수산과학회지
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• 제39권4호
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• pp.333-337
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• 2006

The anti-inflammatory activities of marine actinomycetes were surveyed. In total, 363 strains were isolated from marine sediments, seaweed tissue, and seaweed rhizosphere. Of these, strains 16 and 291-11 showed the most potent anti-inflammatory activity in phorbol-ester-induced mouse ear edema and erythema assays. Strains 16 and 291-11 were isolated from the rhizosphere of the brown seaweeds Sargassum thunbergli and Undaria pinnatifida, respectively, and were identified as Streptomyces macrosporeus and St. praecox, respectively, using 165 rDNA sequence analysis.

• 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.

• 한국해양바이오학회지
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• 제14권2호
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• pp.143-154
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• 2022

We isolated marine actinomycetes, strain D-5 which produces anti-methicillin resistant Staphylococcus aureus (anti-MRSA) compound. Streptomyces sp. D-5 relatively grew well in the 20~25℃, pH 8.0, and NaCl 3.0%. The ethyl acetate extract of D-5 culture was separated by C₁₈ ODS open column and reverse phase HPLC to yield anti-MRSA compound. The molecular weight of this compound was determined to be 898 by a Liquid chromatograph-mass spectrometer (LC-MS). Compared with penicillin G, this compound showed significant anti-MRSA activity. It also exhibited an inhibition zone of 26 mm at a concentration of 64 ㎍/disk and an inhibition zone of 16 mm at a concentration of 16 ㎍/disk against the MRSA KCCM 40511. Furthermore, the co-treatment of HPLC peak 5 compound and vancomycin caused a more rapid decrease in MRSA cells than each compound alone. It showed 86.8% growth inhibition activity within 12 hours at a low concentration of 50 ㎍/mL during co-treatment, and 97.1% growth in-hibition activity within 48 hours against MRSA KCCM 40511. Taken together, our results suggest that Streptomyces sp. D-5 and its anti-MRSA compound could be employed as a potent agent in MRSA infection.

• 한국양식학회:학술대회논문집
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• 한국양식학회 2006년도 수산관련학회 공동학술대회 발표요지집
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• pp.147-148
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• 2006

• 한국미생물·생명공학회지
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• 제50권2호
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• pp.255-269
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• 2022

Actinomycetes isolated from marine habitats represent a promising source of bioactive substances. Here, we report on the isolation, identification, productivity enhancement and application of the bioactive compounds of Streptomyces qinglanensis H4. Eighteen marine actinomycetes were isolated and tested for resistance to seven bacterial diseases. Using 16S rRNA sequencing analysis (GenBank accession number MW563772), the most powerful isolate was identified as S. qinglanensis. Although the strain produced active compound(s) against a number of Gram-negative and Gram-positive bacteria, it failed to inhibit pathogenic fungi. The obtained inhibition zones were 22.0 ± 1.5, 20.0 ± 1, 16.0 ± 1, 12.0 ± 1, 22.0 ± 1 and 24.0 ± 1 mm against Bacillus subtilis ATCC 6633, Escherichia coli ATCC 19404, Enterococcus faecalis ATCC 29212, Pseudomonas aeruginosa ATCC 9027, Candida albicans ATCC 10231 and Staphylococcus aureus ATCC6538, respectively. To maximize bioactive compound synthesis, the Plackett-Burman design was used. The productivity increased up to 0.93-fold, when S. qinglanensis was grown in optimized medium composed of: (g/l) starch 30; KNO₃ 0.5; K₂HPO₄ 0.25; MgSO₄ 0.25; FeSO₄·7H₂O, 0.01; sea water concentration (%) 100; pH 8.0, and an incubation period of 9 days. Moreover, the anticancer activity of S. qinglanensis was tested against two different cell lines: HepG2 and CACO. The inhibition activities were 42.96 and 57.14%, respectively. Our findings suggest that the marine S. qinglanensis strain, which grows well on tailored medium, might be a source of bioactive substances for healthcare companies.