• 한국미생물·생명공학회지
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• 제23권2호
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• pp.209-213
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• 1995

During the screening of inhibitors of melanin biosynthesis from microbial secondary metabolites, a fungal strain MR-93 which was capable of producing high level of an inhibitor was selected from plant leaf. Based on taxonomic studies, the fungus could be classified as a strain of Trichoderma sp.. The active compound (MR-93D) was purified from the culture broth by Diaion HP-20 column chromatography, ethylacetate extraction, Sephadex LH-20 column chromatography and HPLC. The inhibitor was identified as 4-hydroxy-8-isocyano-l-oxaspiro[4-4]cyclonon-8-en-2- one by spectroscopic methods of UV, $^{1}$H-NMR, ESIMS and IR. MR-93D showed a strong tyrosinase inhibitory activity with 0.03 $\mu$g/m of IC$_{50}$ value. It also inhibited melanin biosynthesis with 35 mm inhibition zone at 30 $\mu$g/paper disc in Streptomyces bikiniensis, a bacterium used as an indicator organism in this work.

• Current Research on Agriculture and Life Sciences
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• 제20권
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• pp.49-54
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• 2002

본 연구는 팽이버섯의 병재배용 폐배지를 이용하여 폐상퇴비를 제조하고 퇴비의 이화학성 및 미생물을 분석한 내용이다. 폐상퇴비의 유기물 함량은 43.29%, 유기물함량/질소비는 27.00, 전질소함량은 1.60%, 수분함량은 46.48%, 염농도는 0,64%, $P_2O_5$는 1.32%, $K_2O$ 1.18%로 나타났다. 퇴비내 존재하는 미생물의 수는 $1.6{\times}10^{10}$(cfu/g)으로 나타났으며, 이들 미생물을 동정한 결과 대부분이 Bacillus sp.으로 나타났고 주로 B. lentimobus, B. coagulans, B. brevis, Clostridium thermocellum, Escherichia coli 등이 존재하였고, 방선균류는 주로 Streptomyces thermovulgaris, S. thermofuscus 등 Streptomyce sp.가 주종이며, Micropolyspora faeni도 존재하였다. 곰팡이류는 Aspergillus sp. 나 Penicillum sp. 등이 존재하는 것으로 확인되었다.

• Journal of Microbiology and Biotechnology
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• 제20권5호
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• pp.875-880
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• 2010

Bacterial enoyl-ACP reductase (FabI) has been demonstrated to be a novel antibacterial target. In the course of our screening for FabI inhibitors, we isolated two methyl-branched fatty acids from Streptomyces sp. A251. They were identified as 14-methyl-9(Z)-pentadecenoic acid and 15-methyl-9(Z)-hexadecenoic acid by MS and NMR spectral data. These compounds inhibited Staphylococcus aureus FabI with $IC_{50}$ values of 16.0 and $16.3\;{\mu}M$, respectively, but did not affect FabK, an enoyl-ACP reductase of Streptococcus pneumonia, at $100\;{\mu}M$. Consistent with their selective inhibition for FabI, they blocked intracellular fatty acid synthesis as well as the growth of S. aureus, but did not inhibit the growth of S. pneumonia. Additionally, these compounds showed reduced antibacterial activity against fabI-overexpressing S. aureus, compared with the wild-type strain. These results demonstrate that the methylbranched fatty acids show antibacterial activity by inhibiting FabI in vivo.

• 한국미생물·생명공학회지
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• 제6권4호
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• pp.149-153
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• 1978

1) 토양에서 분리한 Streptomyces 속중에 chitinase를 강하게 분비하는 균 일주를 분리선별하여 그 효소학적 성질 및 생성조건을 조사하였다. 2) 3$0^{\circ}C$에서 진탕배양하면서 경시적으로 본효소 생산을 조사한 바 45시간만에 최대 생산을 보였으며 또한 배지내에 glucose를 0.375% 첨가하였을 때 효소생산이 최대에 달하였으며 그 이상의 농도에서는 효소생산에 오히려 조해현상이 일어났다. 3) 본효소의 최적 pH는 7.0, 최적온도는 5$0^{\circ}C$ 였으며 pH 6.5~8.0에서 비교적 안정하였고 7$0^{\circ}C$에서 20분간 열처리에서도 안정하였다. 4) 금속 이온에 대한 영향은 Co$^{2+}$ 에 의해 활성화 되었고 Hg$^{2+}$, Ni$^{2+}$, Pb$^{2+}$ 등 중금속인 경우 $10^{-2}$ M 정도의 고농도에서 약 50%정도 실활하였다. 또한 본효소는 Aspergillus oryzae에 대해서도 비교적 강하게 작용하였다.

• 한국자기공명학회논문지
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• 제6권1호
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• pp.69-77
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• 2002

During the screening of material which has the antimicrobial activity against aminoglycoside-resistant bacteria, A new material $\varepsilon$-(L-$\beta$-Iysine) polypeptide from a culture medium of Streptomyces sp.(DWGS2) was isolated, and the structure and the physicochemical properties of the new material were elucidated. The new material was separated by column chromatography of the culture medium using Dowex1$\times$2, Silica gel, and Sephadex LH20 etc. The chemical structure and molecular weight were determined with the data of various NMR experiments, MALDI mass, and ESI mass experiments. The antimicrobial activity of $\varepsilon$-(L-$\beta$-Iysine) polypeptide is not only better than equal to the activity of known aminoglycoside type of antibiotics(MIC=3.125 - 6.25ug/mL) but also effective against aminoglycoside-resistant bacteria and fungi. If the mechanism of antimicrobial activity against aminoglycoside- resistant bacteria is figured out, the $\varepsilon$-(L-$\beta$-Iysine) polypeptide can be utilized for the treatment of diseases caused by aminoglycoside-resistant bacteria.

• 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.

• 한국미생물·생명공학회지
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• 제3권2호
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• pp.63-68
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• 1975

Streptomyces속에서 분이한 물질의 생물학적 활성을 검색하던 중 어유에 대한 독성물질을 강하게 생성하는 균 1수를 선별하여 그 생화학적 성질을 검토하였다. 1. 분이된 물질의 독성은, 예로서 Pseudorasbora parva T. et. S. (체중 0.~0.5g, 신장 3.0~4.0cm)에 대한 살어역은 5ug/ml에서 30분, 25ug/ml에서 50분이었으며 Carassius carassius L. (체중 2.0g, 유장 5.0cm)온 50ug/m1용액에서 70분간 생존할 수 있었다. 2. 본 물질은 산성 및 유기용매에서는 비교적 안정하여 pH 4.0에서 15시간까지 처이하였을 경우, 또 CHCI$_3$, acetone 용액에서 약 5일간까지 처이하였을 때에도 거의 독성이 감소되지 않았다. alkali성 및 열에 대하여서는 불안정한 물질로써 pH 8.0에서 5분간 처이하였을 때 물질이 상당히 실활되었으며 6$0^{\circ}C$以上의 온도에서는 비교적 격히 실활되었다. 3. 25ug/m1 수용액에서 Pseudorabora parva에 대하여 약 20분간 이상 처이로서는 회생이 불가능함을 알았다. 이상과 같은 성질을 가진 본 독성물질은 선별된 균주의 배양여액을 pH 3.0으로 하강하여 NaCl로서 포화시킨 후 CHCl$_3$에 전용하여 농축하르로써 비교적 간단한 방법으로 분리할 수 있었다.

• Journal of Microbiology and Biotechnology
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• 제30권7호
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• pp.1082-1091
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• 2020

Microbial transglutaminases (MTGs) are widely used in the food industry. In this study, the MTG gene of Streptomyces sp. TYQ1024 was cloned and expressed in a food-grade bacterial strain, Bacillus subtilis SCK6. Extracellular activity of the MTG after codon and signal peptide (SP Ync M) optimization was 20 times that of the pre-optimized enzyme. After purification, the molecular weight of the MTG was 38 kDa and the specific activity was 63.75 U/mg. The optimal temperature and pH for the recombinant MTG activity were 50℃ and 8.0, respectively. MTG activity increased 1.42-fold in the presence of β-ME and 1.6-fold in the presence of DTT. Moreover, 18% sodium chloride still resulted in 83% enzyme activity, which showed good salt tolerance. Cross-linking gelatin with the MTG increased the strength of gelatin 1.67 times and increased the thermal denaturation temperature from 61.8 to 75.8℃. The MTG also significantly increased the strength and thermal stability of gelatin. These characteristics demonstrated the huge commercial potential of MTG, such as for applications in salted protein foods.

• The Plant Pathology Journal
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• 제15권1호
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• pp.14-20
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• 1999

Twenty isolates of Helminthosporium species were obtained from various grass plants and tested for controlling efficacy on the development of plant diseases. An isolate of Helminthosporium sp. TP-4 was chosen and six antibiotic substances were purified from cultures of the fungus by repeated silica gel column chromatography and preparative thin-layer chromatography. They were identified as ophiobolin a, 6-epiophiobolin A, 3-anhydroophiobolin A, 3-anhydro-6-epiophiobolin A, iphiobolin B, and iphiobolin I mainly by mass spectrometry and nuclear magnetic resonance spectrometry. Ophiobolins inhibited the growth of a grampositive bacterium Streptomyces griseus, but were not active against gram-negative bacteria. They also showed an antifungal activity. In in vivo tests, iphiobolin B exhibited potent controlling activities against rice blast, tomato late blight, and wheat leaf rust with control values more than 90% and 70% at concentration of $500\mu\textrm{m}$/ml and 100 ${\mu}{\textrm}{m}$/ml. Ophiobolin A and 6-epiophiobolin A controlled the development of wheat leaf rust more than 80% at concentrations of 100 /ml and $500\mu\textrm{m}$/ml respectively. 3-Anhydro-6-epiophiobolin A was not active against any plant disease. On the other hand, the A-series ophiobolins other than 3-anhydroophiobolin A showed stronger phytotoxic activity in a leaf-wounding assay using 8 plant species than those of 3-anhydroophiobolin A, ophiobolin B, and ophiobolin I. The results indicate that there is little correlation between antifungal activity and phytotoxicity of ophiobolins.

• 한국미생물·생명공학회지
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• 제7권3호
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• pp.135-140
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• 1979

특이하게도 일단 어떤 원인으로든지 변성이 일어나서 침전이 형성되고 난 후에는 그 변성으로 인하여 다시 용해되지 않는 penicillinase를 생성분비하는 Streptomyces 속 균주 AS-727을 토양으로부터 얻었으며, 이 균의 효소생산성과 이 효소의 일반적성질을 검토한 결과는 다음과 같다. 1) 본 효소의 생산을 위해서는 질소원으로서 sodium nitrate, 탄소원으로서 glucose 나 maltose를 사용하여 4 일간 배양하는 것이 바람직했으며 2) 정제는ammonium sulfate로 완전포화시켜 생성된 침전을 원심분리로 모아 그것을 투석해서 조정제효소를 얻는데, 이때 투석할 때 침전은 용해 되지 않는다. 3) 본 효소의 최적 pH는 중성부근 (6.0~8.0)이며 최적온도는 4$0^{\circ}C$ 근처이고, 4) 안정 pH 범위는 4.0~9.0으로서 비교적 넓었으며 열에 대해서는 4$0^{\circ}C$에서는 안정했으며 6$0^{\circ}C$와 8$0^{\circ}C$에서 60 분간 처리하면 각각 약 30%와 40%가 실활되었다. 5) 본 효소의 활성에 있어서 zinc chloride가 $10^{-3}$ M 농도에서 약 20%, $10^{-2}$ M 이상의 고농도에서는 95% 이상을 조해하였다. 6) 그리고 동결이나 명종 고류 또는 유기용매로 일단 형성된 효소단백침전은 다시 용해되지 않는 특이한 성질을 가졌다.