• The Plant Pathology Journal
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• 제28권2호
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• pp.185-190
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• 2012

Sclerotinia sclerotiorum is a serious pathogen which causes yield loss in many dicotyledonous crops including potato. The objective of this study was to assess the potential of biofumigation using three Brassica crops including Brassica napus, B. juncea and B. campestris against potato stem rot caused by S. sclerotiorum by in vitro tests. Both macerated and irradiated dried tissues were able to reduce radial growth and sclerotia formation of five pathogen isolates on PDA, but macerated live tissues were more effective. Compared with other tested crops, B. juncea showed more inhibitory effect against the pathogen. The volatile compounds produced from macerated tissues were identified using a gas chromatograph-mass spectrometer. The main identified compounds were methyl, allyl and butyl isothiocyanates. Different concentrations of these compounds inhibited mycelial growth of the pathogen in vitro when applied as the vapor of pure chemicals. A negative relationship was observed between chemicals concentrations and growth inhibition percentage. In this study, it became clear that the tissues of local Brassica crops release glucosinolates and have a good potential to be used against the pathogen in field examinations.

• 미생물학회지
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• 제51권2호
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• pp.108-114
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• 2015

본 연구에서는 Streptomyces subrutilus P5의 생장과 세포내 외 철 함유 superoxide dismutase 활성을 비교 분석하여 철함유 superoxide dismutase의 분비 시점을 확인하고 분자 수준에서 이 효소의 분비에 관여하는 유전정보를 확인하고자 하였다. Streptomyces subrutilus P5의 균체 생장은 건체 중량을 측정하여 결정하였다. Glucose는 log phase에서 급격히 소모되어 24시간 후에 이르러 완전히 고갈되었다. 세포내의 철 함유 superoxide dismutase는 배양 후 3시간에 나타나며 세포외 철 함유 superoxide dismutase는 배양 후 7.5시간부터 나타난다. 따라서 superoxide dismutase는 용균에 의해서가 아니라 능동적인 분비기작에 의해서 세포 외로 분비된 것으로 추측할 수 있다. Streptomyces subrutilus P5의 sodF에는 signal peptide 유전정보가 존재하지 않았다. 그러나 sodF의 상류지역에서 다른 세균의 type III 분비단백질 유전자와 유사한 type III 분비상자가 발견되었다. Streptomyces 균주에서 type III 분비단백질이 존재할 가능성이 있음을 처음으로 제시하였다.

• Journal of Microbiology and Biotechnology
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• 제15권2호
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• pp.274-280
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• 2005

A chitinase was purified from the culture supernatant of Paenibacillus illinoisensis KJA-424 by protein precipitation, DEAE-Sephadex anion-exchange chromatography, and Sephadex G-150 gel filtration. The molecular weight of the purified chitinase was 54 kDa on SDS-PAGE and activity staining. Optimal pH and temperature were pH 5.0 and 60$^{circ}$C, the presence of 10 ruM Ag$^{+}$ and Hg$^{2+}$ inhibited the activity by $92.1/%$ and $97.7/%$, and the K$_{m}$ and V$_{max}$ values were 1.12 mg chitin mrl and 1.48$\mu$mol GlcNAc min$^{-1}$, respectively. The enzyme hydrolyzed tetramer to dimer, pentamer to dimer and trimer, and hexamer to dimer, trimer and tetramer, indicating an endo-splitting mechanism. The chitinase had no hydrolytic activity toward dimer and trimer. The chitinase inhibited the mycelial growth of Rhizoctonia solani, suggesting an antifungal property.

• 미생물학회지
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• 제27권1호
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• pp.56-62
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• 1989

Chitin 분해 활성이 높은 Streptomyces 균주들을 인삼재배 토양에서 분리하고, 그 균주들이 인상뿌리 썩음 병균인 Fµsarium solani 에 미치는 길항효과와 그 작용을 조사하였다. 분리된 Streptomyces 중 몇 균주는 F. solani 의 포자발아와 발 아판의 생장을 억제하였고 균사를 분해하였으며, 동시에 세포벽 분해효소로 알려친 Chitinase를 생산하였다. 그중에서도 S alboniger ST 59 와 S. roseolilacinus ST 129 는 길항효과가 아주 좋았는데, 병원균의 분생포자를 두 Streptomyces 의 농축배 양여액에 14일간 처리하였을 때 포지숫자가 처음 정종 정도의 20%로 줄어을였다. 특히 S. alboniger ST 59는 뱅균인 F solani의 분생포자, 균사 뿐만 아니라 분해되기 어려운 후막포자까지도 분해하였다. 이것으로 비푸어 보건데, F. solani의 이 Streptomycetes에 의한 억제작용은 항생물질에 영향을 받은 병균이 Chitinase에 의해 분해된 것으로 생각된다.

• KSBB Journal
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• 제13권2호
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• pp.214-219
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• 1998

Polymerase chain reaction(PCR) was conducted to obtain the gene encoding glucose oxidase(GOD) from Aspergillus niger(ATCC 2110) and the DNA sequence determined was coincided with published GOD sequence from A. niger. Recombinant transforming vector containing GOD and hygromycin B(hyg.B) resistant gene(hph) was constructed and used for further transformation of A. niger ATCC 2110. Selectivity of hyg.B against A. niger differed depending on which media were used i.e., nutrient-rich media such as potato dextrose agar(PDA) and complete medium(CM) showed only 50% growth inhibition at 400 $\mu$m ml$^-1$ of hyg.B while the minimal media inhibited mycelial growth completely at 200 $\mu$m ml$^-1$ of hyg.B. Twenty to sixty putative transformants were isolated from the hyg.B-containing minimal top agar, transferred successively onto alternating selective and nonselective media for a mitotic stability of hyg.B resistance and, then, single-spored. Among the stable transformants, the transformant(GOD1-6) grown by flask culture showed the considerable increase of extracellular GOD activity, which was estimated to the degree of 50% - 100% comparing to that of wild type. Transformation of tGOD1-6 was resulted from integration of the vectors into heterologous as well as homologous regions of the A. niger genome. Southern blot analysis revealed that there were two independent integrations of vector into fungal genome and one into the GOD gene due to homologous recombination. In addition, GOD activity and sodium gluconate production when tGOD1-6 was fed-batch fermented were enhanced 11 fold and 2.25 fold, respectively, compared to that of the wild type.

• Archives of Pharmacal Research
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• 제16권4호
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• pp.336-338
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• 1993

The immunomodulating activity of Kp, an antitumor protein-polysacchanide preparation from the shake-cultured mycelia of Phellinus linteus, was investigated in ICR mice subcutaneously implanted wit $1\times10^6$ cells of sarcoma 180. The mice were intraperitoneally administered with Kp at a does of 100 mg/kg once daily for five consecutive days starting from 24 hrs after the tumor implantation. Ten days after the last injection, the mice were immunized with $1\times10^7$ or $4\times10^8$ sheep red blood cells (SRBC) and five days later, the antibody-forming immune response were assessed by direct hemolytic plaque assay. To an immunization does of $1\times10^7$ SRBC, the Kp-treated mice elicied a successful humoral immune response despite the turmor-burden and produced $259\times10^3$ plaque-forming cells (PFC)/spleen, while the corresponding tumor-bearing control mice showed virtually no reponse $(2.0\times10^3$ PFC/spleen) (the stimulation index=129.5). However, to an immunization dose of $4\times10^8$ SRBC, both of the control mice and Kp-treated mice showed almost the same level of strong humoral immune response. From these data it is clear that Kp effectively restores the humoral immune response of the turmor-bearing ICR mice.

• 한국식품과학회지
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• 제10권1호
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• pp.46-51
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• 1978

황변미독(黃變米毒)의 일종인 luteoskyrin의 동정(同定) 및 정량법(定量法)을 검토한 후 변질미에서 분리된 Pen. islandicum의 luteoskyrin 생성능(生成能)을 추구한 결과는 다음과 같다. 1) Luteoskyrin은 0.5 N oxalic acid impregnated silicagel G plate로서 acetone : n-hexane : water(6:3:1.5, upper layer)를 전개용매로하는 TLC방법에서 분리(分離)가 가장 좋았다. 분리된 황색물질의 최대흡수파장(吸收波長)은 426, 448nm이었으며 chromatogram을 태양광선에 $2{\sim}3$시간 노출시 자색(紫色)으로 변하였다. 2) Luteoskyrin의 정량법으로서 TLC전개(展開)후 용출비색법(溶出比色法)에서는 4 ppm, densitometry에서는 0.1 ppm이 검출한계(檢出限界)이었다. 미곡 중의 허용량(許容量)을 3.68 ppm이하로 정설할 경우 곡류시료 중 luteoskyrin의 검색(檢索)에는 densitometry가 적합할 것이다. 3) Pen. islandicum에 의한 luteoskyrin 생성능은 Czapek 액체배지에서는 균계체(菌系體) 1g당 11mg, 가압살균한 쌀에서는 1g당 40mg이었다.

• 미생물학회지
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• 제33권4호
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• pp.252-256
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• 1997

담자균류 백색부후균의 일종인 흰구름버섯(Coriolus hirsutus)을 실험균주로 하여 수종의 난분해성 방향족염료의 분해능을 측정하였다. 사용된 4종류의 염료 중, triphenyl methane 염료인 bromophenol blue가 탈색율 95% 이상으로 가장 잘 탈색되었으며, Congo red와 Poly R-478은 이보다는 낮은 57%, 55%가 탈색되었다. 그러나, heterocyclic 염료인 methylene blue는 본 균주에 의해 거의 탈색되지 않았으며, UV-visible spectrum상에서의 심색성 이동만 관찰되었다. 세포외 laccase와 peroxidase의 활성은 각 염료의 탈색율과 비례하여 나타났으며, 최대 활성 또한 최대 탈색시기에 관찰되었다. 효소의 활성 염색시 모든 염료의 탈색배지에서 공통적인 laccase와 peroxidase의 활성 띠가 관찰되었다. 이러한 결과로 볼 때, 세포외 laccase와 peroxidase가 난분해성 염료의 탈색에 중요한 역할을 할 것으로 판단된다.

• Journal of Microbiology and Biotechnology
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• 제31권9호
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• pp.1241-1255
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• 2021

This study was carried out to explore a non-chemical strategy for enhancing productivity by employing some antagonistic rhizobacteria. One hundred eighteen bacterial isolates were obtained from the rhizospheric zone of various crop fields of Gangwon-do, Korea, and screened for antifungal activity against Fusarium wilt (Fusarium oxysporum f. sp. lactucae) in lettuce crop under in vitro and in vivo conditions. In broth-based dual culture assay, fourteen bacterial isolates showed significant inhibition of mycelial growth of F. oxysporium f. sp. lactucae. All of the antagonistic isolates were further characterized for the antagonistic traits under in vitro conditions. The isolates were identified on the basis of biochemical characteristics and confirmed at their species level by 16S rRNA gene sequencing analysis. Arthrobacter sulfonivorans, Bacillus siamensis, Bacillus amyloliquefaciens, Pseudomonas proteolytica, four Paenibacillus peoriae strains, and Bacillus subtilis were identified from the biochemical characterization and 16S rRNA gene sequencing analysis. The isolates EN21 and EN23 showed significant decrease in disease severity on lettuce compared to infected control and other bacterial treatments under greenhouse conditions. Two bacterial isolates, EN4 and EN21, were evaluated to assess their disease reduction and growth promotion in lettuce in field conditions. The consortium of EN4 and EN21 showed significant enhancement of growth on lettuce by suppressing disease caused by F. oxysporum f. sp. lactucae respectively. This study clearly indicates that the promising isolates, EN4 (P. proteolytica) and EN21 (Bacillus siamensis), can be commercialized and used as biofertilizer and/or biopesticide for sustainable crop production.

• Mycobiology
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• 제49권2호
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• pp.151-160
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• 2021

Despite recent studies, relatively few are known about the diversity of fungal communities in the deep Atlantic Ocean. In this study, we investigated the diversity of fungal communities in 15 different deep-sea sediments from the South Atlantic Ocean with a culture-dependent approach followed by phylogenetic analysis of ITS sequences. A total of 29 fungal strains were isolated from the 15 deep-sea sediments. These strains belong to four fungal genera, including Aspergillus, Cladosporium, Penicillium, and Alternaria. Penicillium, accounting for 44.8% of the total fungal isolates, was a dominant genus. The antiaflatoxigenic activity of these deep-sea fungal isolates was studied. Surprisingly, most of the strains showed moderate to strong antiaflatoxigenic activity. Four isolates, belonging to species of Penicillium polonicum, Penicillium chrysogenum, Aspergillus versicolor, and Cladosporium cladosporioides, could completely inhibit not only the mycelial growth of Aspergillus parasiticus mutant strain NFRI-95, but also the aflatoxin production. To our knowledge, this is the first report to investigate the antiaflatoxigenic activity of culturable deep-sea fungi. Our results provide new insights into the community composition of fungi in the deep South Atlantic Ocean. The high proportion of strains that displayed antiaflatoxigenic activity demonstrates that deep-sea fungi from the Atlantic Ocean are valuable resources for mining bioactive compounds.