• Journal of Microbiology and Biotechnology
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• 제29권9호
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• pp.1412-1423
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• 2019

The filamentous fungus Aspergillus tubingensis that belongs to the black Aspergillus section has the capacity to produce high-value metabolites, for instance, naphtho-gamma-pyrones (NGPs). For these fungal secondary metabolites, numerous biological properties of industrial interest have been demonstrated, such as antimicrobial, antioxidant and anti-cancer capacities. It has been observed that production of these secondary metabolites is linked with fungal sporulation. The aim of this research was to apply osmotic and oxidative environmental stresses to trigger the production of NGPs in liquid cultures with CYB (Czapek Dox Broth). In addition, numerous parameters were tested during the experiments, such as pH value, incubation time, container geometry, and static and agitation conditions. Results demonstrate that the produced amount of NGPs can be enhanced by decreasing the water activity ($a_w$) or by adding an oxidative stress factor. In conclusion, this study can contribute to our knowledge regarding A. tubingensis to present an effective method to increase NGP production, which may support the development of current industrial processes.

• Journal of Ceramic Processing Research
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• 제20권1호
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• pp.18-23
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• 2019

Chemical looping combustion (CLC) is a promising carbon capture and storage (CCS) technology whose efficiency and cost primarily relies on the oxygen carrier materials used. In this paper, gadolinium-doped ceria (GDC, Ce0.9Gd0.1O1.95) was added as a promoter to improve the oxygen transfer rate of MgMnO3-δ oxygen carrier materials. Increasing GDC content significantly increased the oxygen transfer rate of MgMnO3-δ-GDC composites for the reduction reaction due to an increase in the surface adsorption of CH4 via oxygen vacancies formed on the surface of the GDC. On the other hand, the oxygen transfer rate for the oxidation reaction decreased linearly with increasing GDC content due to the oxygen storage ability of GDC. Adsorbed oxygen molecules preferentially insert themselves into oxygen vacancies of the GDC lattice rather than reacting with (Mg,Mn)O to form MgMnO3-δ during the oxidation reaction.

• Bulletin of the Korean Chemical Society
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• 제32권6호
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• pp.1891-1896
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• 2011

On the basis of potent HDAC-inhibitory activity and anticancer activity of SAHA, novel SAHA derivatives 3a-d and 7 with a bulky cap such as p-dimethylaminophenyl, 4-phenylaminophenyl, 4-phenyloxyphenyl, 9H-fluorenyl or naphthalenyl ring were synthesized starting from the corresponding aryl amines or naphthalenyl acetic acid using an EDC-mediated amide coupling reaction in the presence of HOBt followed by a nucleophilic addition-elimination reaction with hydroxylamine. Compounds 3b, 3c and 3d showed more potent inhibitory activity on total HDACs (14~27-fold), HDAC1 (8~15-fold), HDAC2 (1.3~25-fold) and HDAC7 (1~3-fold) and more potent anticancer activity (2~22-fold) against MCF-7, MDA-MB-231, MCF-7/Dox, MCF-7/Tam, SK-OV-3, LNCaP and PC3 human cancer cell lines than SAHA.

• 한국미생물·생명공학회지
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• 제20권1호
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• pp.14-19
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• 1992

부패한 나무, 퇴비, 제지공장의 폐지 및 폐수 등으로부터 분리한 300여 종류의 섬유소 분해균 중 xylanase 활성이 다른 균주에 비해 비교적 높았던 33번 균주를 균의 형태학적, 생화학적 특성과, 균체 지방산 조성에 의하여 Pseudomonas sp.로 동정하였다. Xylanase 활성의 최적 온도외 최적 pH는 각각 $50^{\circ}C$와 5.5이었고, 효소의 안정성은 $45^{\circ}C$ 이하의 온도와 pH 5.0에서 7.0 사이에서 유지되었다. 이 균주가 생산하는 xylanase는 효소반응분해물의 paper chromatography에 의하여 주로 exo-type의 xylanase임이 밝혀졌다.

• International Journal of Industrial Entomology and Biomaterials
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• 제10권2호
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• pp.119-123
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• 2005

Benomyl-resistant mutants of entomopathogenic fungus, Metarhizium anisopliae were isolated and their physiological characteristics were investigated. These militants were obtained spontaneously or by UV irradiation in benomyl-treated media. Four spontaneous (S-2, S-11, S-18, S-19) and four UV-induced (UV-4, UV-5, UV-19, UV-24) mutants, which grow stably and normally were selected. No significant differences in conidia or hyphal shape, conidia viability, mycelial biomass, or virulent to the diamondback moth were observed between the wild type and their mutants. But differently from the mycelial growth of other benomyl-resistant mutants which was slower than that of the wild type on a modified Czapek-Dox, SDAY, $4\%$ chitin, or $1\%$ skim milk medium, that in the spontaneous mutants, S-18 and S-19, did not show any difference from the wild type. Especially, S-18 and S-19 grew well at benomyl concentrations up to 50 times or higher than that which inhibits wild type proliferation. These results suggested that S-18 and S-19 could potentially be used with the fungicide, benomyl.

• Journal of Pharmaceutical Investigation
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• 제39권6호
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• pp.423-429
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• 2009

Liposomes have been used as one of the efficient carriers for drug delivery. In this study, anionic liposomes of which surface was modified by using both electrostaic interaction between anionic liposomes and cationically charged BSA molecules at lower pH than isoelectric point (pI) of BSA and denaturation of the BSA-coated liposomes by thermal treatment. The thermally denatured BSA-coated liposomes (DBAL) had mean particle diameter of 125.2${\pm}$1.7 nm and zeta potential value of -22.4${\pm}$4.5 mV. Loading efficiency of model drug, doxorubicin (DOX), into liposomes was 83.0${\pm}$2.6%. Results of in vitro stability study of DBAL in blood plasma showed that the mean particle diameter of DBAL 400 did not increase in blood plasma and adsorption of plasma protein was much less than plain or anionic liposomes. Intracellular uptake of DBAL 400 evaluated by confocal microscopy observation was higher than that of PEG liposomes.

• Journal of Microbiology and Biotechnology
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• 제8권4호
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• pp.341-346
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• 1998

Optimization for the production of Pest an was followed by the Plackett-Burman Design, using modified Czapek-dox medium as the starting point. At the flask level, $K_2HPO_4$, $MgSO_4{\cdot}7H_2O$, and aeration variables positively affected the Pestan production, DCW (dry cell weight), apparent viscosity, and flocculating activity response. KCI and $FeSO_4{\cdot}7H_2O$ negatively affected the Pestan production, DCW, apparent viscosity, and flocculating activity response. Aeration variable was shown to have a positive effect on only the flocculating activity response among Pestan production, DCW, and apparent viscosity responses. In comparison of the positive and negative variables media conditions, Pestan production and flocculating activity differed by about 9 and 125 times, respectively. In particular, at the jar fermentor level, the aeration variable was the most important factor of the all responses (pestan production, DCW, apparent viscosity, flocculating activity, and anionic charge density). The flocculating activity and apparent viscosity of Pestan were closely related to the molecular chain length and charge density.

• The Plant Pathology Journal
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• 제35권6호
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• pp.674-683
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• 2019

Some species of the Trichoderma genus are reported as the major problem in oak wood mushroom production in Korea. In spite of economic loss by the fungi, scientific information on airborne Trichoderma species is not much available. To generate information for disease management development we analyzed airborne Trichoderma. A total of 1,063 fungal isolates were purely obtained from indoor air sampling of cultivation houses used for oak wood mushroom using sawdust media. Among the obtained isolates, 248 isolates were identified as Trichoderma fungi including T. harzianum, T. atroviride, T. citrinoviride, and T. pseudokoningii, by morphological and molecular analysis. T. harzianum was dominant among the four identified species. All the four Trichoderma species grew fast on solid nutrient media tested (potato dextrose agar [PDA], malt extract agar [MEA], Czapek's Dox + yeast extract agar [CYA] and cornmeal dextrose agar). Compact mycelia growth and mass spore production were better on PDA and CYA. In addition, T. harzianum and T. citrinoviride formed greenish and yellowish mycelium and spores on PDA and CYA. Greenish and yellowish pigment was saturated into PDA only by T. pseudokoningii. These four Trichoderma species could produce extracellular enzymes of sawdust substrate degradation such as β-glucosidase, avicelase, CM-cellulase, amylase, pectinase, xylanase, and protease. Their mycelia inhibited the growth of oak wood mushroom mycelia of two tested cultivars on dual culture assay. Among of eleven antifungal agents tested, benomyl was the best to inhibit the growth of the four Trichoderma species. Our results demonstrate that the airborne Trichoderma fungi need to be properly managed in the cultivation houses for safe mushroom production.

• 한국균학회지
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• 제15권3호
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• pp.158-168
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• 1987

1. Cassava 전분(澱粉)을 이용(利用)하여 곰팡이를 $28^{\circ}C$에서 96시간(時間) 액체정치(液體定置) 배양(培養)한 바 배지중(培地中)의 Cassava 전분함량(澱粉含量)이 6%, 72시간(時間)일 때에 균체량(菌體量)이 가장 많았다. 2. Cassava 전분(澱粉)이 6% 함유(含有)된 배지(培地)에서 곰팡이를 배양(培養)하여 얻은 균체단백질량(菌體蛋白質量)은 Rhizopus는 48시간(時間) 배양(培養)하였을때 가장 많았고, Aspergillus niger 및 Aspergillus fumigatus에서는 72시간(時間) 배양(培養)했을 때 균체단백질량(菌體蛋白質量)이 많았다. 3. Cassava 전분량(澱粉量)을 4%, 6% 및 8%되게 변화(變化)시킨 배지(培地)에서 분리균(分離菌)을 접종(接種)하여 96시간(時間) 배양(培養)하면서 24시간(時間)마다 배양여액(培養濾液) 중(中)의 m-amylase의 활성(活性)을 측정(測定)한 바 8% 농도(濃度)에서 Aspergillus niger 및 Aspergillus fumigatus는 72시간(時間)일 때 높은 D.P 값을 얻었고. Rhizopus 는 144시간(時間)일 때 D.P 값이 높았다.

• 한국균학회지
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• 제15권4호
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• pp.231-237
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• 1987

1. Cassava의 전분을 이용하여 검정곰팡이(Aspergillus niger)를 $30^{\circ}C$에서 4일 동안 진탕배양 하였을 때 배지 중 Cassava의 전분의 함량이 4%, 6%, 8% 및 10%일 때 96시간 배양된 각각의 균체량은 13.35mg/ml, 15.78mg/ml, 14.48mg/ml 및 9.93mg/ml이었다. 2. Cassava의 전분을 이용하여 검정곰팡이를 $30^{\circ}C$에서 4일 동안 진탕배양하여 얻어진 균체를 Lowry 방법에 의하여 그 균체단백을 측정한 바 배지 중의 Cassava의 전분의 함량이 4%, 6%, 8% 및 10%일 때 각각의 균체단백은 2.6mg/ml, 2.7mg/ml, 2.5mg/ml 및 1.7mg/ml이었으며 6% 함유구에서 균체단백의 양이 가장 많았다. 3. 배지 중의 Cassava의 전분량을 6%로 맞추고 질소원의 종류를 $NaNO_3,\;(NH_4)_2SO_4$ 및 Urea를 사용하고 질소량을 Czapeck-Dox 배지에 있는 $NaNO_3$의 질소량의 50%, 100%, 200%, 400% 및 $800^{\circ}C$되게 변화시키면서 진탕배양한 바 균체생산량에는 차이가 없었다.