• 한국미생물·생명공학회지
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• 제25권5호
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• pp.512-519
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• 1997

RNA accumulating strain of Torulopsis versatilis MT-1 was cultured in molasses medium for higher contents of RNA in cell. Yeast cells were harvested at logarithmic phase on synchronous culture. Yield of cells on dry base to input sugar was 59.5%. Crude protein content was 55.1% in cell. RNA content was 13.9%. Some problems found in the process for the preparation of yeast extracts were improved by the addition of culture broth of Streptomyces faecalis MSF which secrete RNase (5' nuclease and 5' adenylic acid deaminase). When the culture broth of S. faecalis MSF was added in autolysis process 46% of RNA in cell was converted to I and G(5' inosinic acid and 5' guanylic acid) in extract. By addition of 3-7% culture broth of S.faecalis MSF in autolysis or enzymolysis process at the start or early stage, RNA in extract was converted easily to I and G and protein in cells was easily extracted and hydrolyzed to amino acid. Taste of those yeast extracts was delicious. The yeasty smell in yeast extracts was removed. And cell debris was easily removed from extract.

• 미생물학회지
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• 제47권3호
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• pp.218-224
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• 2011

케피어그레인을 이용하여 제조한 요쿠르트로부터 젖산균 OA18을 분리하여 그 특성을 조사하였다. 분리된 균주는 그람양성, 구균이었으며, 혐기적 조건에서 이산화탄소를 생성하였다. 균주는 MRS 배지에서 $30-37^{\circ}C$ 온도 범위와 pH 7.0-9.0범위에서 잘 자랐으며, 성장을 위한 최적 온도와 pH는 각각 $37^{\circ}C$와 pH 7.0이었다. 분리된 젖산균은 리보오스, D-글루코오스, cellobiose, D-trehalose 등을 분해하여 산을 생성하였고, L-xylose, D-melibiose, inositol은 분해하지 못하였다. 16S rRNA gene 염기서열 분석을 통해 OA18 균주는 유전자은행(NCBI)에 등재되어 있는 Enterococcus faecalis (AB012212)의 염기서열과 99.8% 동질성이 있음을 확인하였다. 이와 같은 생화학적 특성과 염기서열 분석 결과를 토대로 분리된 균주를 Enterococcus faecalis OA18로 명명하였다. E. faecalis OA18균주는 오르니틴 생성능력과 Streptomyces coelicolor subsp. Flavus, S. coeruleorubidus, S. coeruleoaurantiacus, S. coelicolor, S. coeruleoprunus 대한 항균 활성을 보유하고 있었으며, 0-7% NaCl을 함유하는 MRS 배지에서 증식이 가능한 것으로 조사되었다.

• Journal of Microbiology
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• 제40권1호
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• pp.43-50
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• 2002

A cluster of genes encoding the pyruvate dehydrogenase complex (PDC) of Streptomyces seoulensis, a Gram-positive bacterium, was cloned and sequenced. The genes of S. seoulensis consist of four open reading frames. The first gene, lpd, which encodes a lipoamide dehydrogenase, is followed by pdhB encoding a dihydrolipoamide acetyltransferase (E2p), pdhR, a regulatory gene, and pdhA encoding a pyruvate dehydrogenase component (Elp). Elp had an unusual homodimeric subunit, which has been known only in Gram-negative bacteria S. seoulensis E2p contains two lipoyl domains like those of humans and Streptomyces faecalis. The pdhR gene appears to be clustered with the structural genes of S. seoulensis PDC. The PdhR-overexpressed S. seoulensis howed growth retardation and the decrease of Elp, indicating that PdhR regulates the function of PDC by repressing the expression of Elp. A strain of Streptomyces licidans overexpressing S. seoulensis PdhR showed a significant decreasein the level of actinorhodin, implying a regulatory role for Streptomyces PDC in antibiotic biosynthesis.

• Applied Biological Chemistry
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• 제38권6호
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• pp.516-521
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• 1995

항 MRSA 물질을 찾기 위하여 찬국 해양 토양을 검색하였고, 거기서 분리된 방선균의 이차 대사물질 중 항 MRSA 효능을 보이는 물질을 AM3이라고 명명하고 이에 대한 연구를 하였다.

• 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.