• Journal of Microbiology and Biotechnology
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• v.21 no.9
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• pp.960-967
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• 2011

Tannin acyl hydrolase, also known as tannase, is an enzyme with important applications in the food, feed, pharmaceutical, and chemical industries. However, despite a growing interest in the catalytic properties of tannase, its practical use is very limited owing to high production costs. Several studies have already demonstrated the advantages of solid-state fermentation (SSF) for the production of fungal tannase, yet the optimal conditions for enzyme production strongly depend on the microbial strain utilized. Therefore, the aim of this study was to improve the tannase production by a locally isolated A. niger strain in an SSF system. The SSF was carried out in packed-bed bioreactors using polyurethane foam as an inert support impregnated with defined culture media. The process parameters influencing the enzyme production were identified using a Plackett-Burman design, where the substrate concentration, initial pH, and incubation temperature were determined as the most significant. These parameters were then further optimized using a Box-Behnken design. The maximum tannase production was obtained with a high tannic acid concentration (50 g/l), relatively low incubation temperature ($30^{\circ}C$), and unique low initial pH (4.0). The statistical strategy aided in increasing the enzyme activity nearly 1.97-fold, from 4,030 to 7,955 U/l. Consequently, these findings can lead to the development of a fermentation system that is able to produce large amounts of tannase in economical, compact, and scalable reactors.

• Korean Journal of Food Science and Technology
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• v.28 no.2
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• pp.366-370
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• 1996

Gamma irradiation was applied to red ginseng powder for improving its hygienic quality 7.5 kGy of gamma irradiation completely eliminated the microorganisms contaminated in red ginseng powder. And there was no growth of microorganisms after six months of storage at room temperature. The molds isolated from red ginseng powder were identified as Pen. commune, Asp. niger, Asp. versicolor and Asp. Unguis, the conidia of which showed the decimal reduction dose ($D_{10}$ value) of 0.37-0.50 kGy, 0.24-0.31 kGy, 0.25-0.36 kGy and 0.28-0.41 kGy and inactivation factor of 5.0-6.5, 7.4-9.3, 6.5-9.1 and 6.1-8.4, respectively The radiosensitivity of identified molds' conidia decreased in medium containing red ginseng extract.

• KSBB Journal
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• v.5 no.2
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• pp.141-149
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• 1990

$\beta$-glucosidase derived from Aspergillus niger was immobilized by (1) covalent linkage on chitin and chitosan with glutaraldehyde, (2) adsorption on DEAE-cellulose and Amberite IRA93 after succinylation, and (3) entrapment on alginate and polyacrylamide gels with various cross linking agents. The retention yield of $\beta$-glucosidase immobilized on chitosan was 31.5% and operational stability was 69% after continuous operation at column reactor(5$0^{\circ}C$ at pH 4.8) for 15 days. The retention yield and operational stability were 24.7% and 60% respectively, in adsorption on Amberite IRA 93. On the other hand, the entrapment method by alginate and polyacrylamide gel was identified to be not appropriate due to the continuous elution of inlmobilized $\beta$-glucosidase. Optimum conditions for the immobilization on chitosan were also studied with optimum pH of 4.8 and glutaraldehyde concentration of 0.4%(w/v). The properties and stability of immobilized $\beta$-glucosidase are also investigted. The conversion yield of cellobiose to glucose was also analyzed using the column type enzyme reactor to evaluate the effectiveness of immobilized enzyme.

• Journal of Pharmacopuncture
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• v.15 no.1
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• pp.23-28
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• 2012

Objective: This experimental study was designed to investigate the safety and the effectiveness of Samjeong pharmacopuncture solution (SPS) manufactured by using a the lowtemperature extract on process. Methods: To identify the safety and the effectiveness of using SPS as eye drops, we performed applied eye irritation tests on rabbits and antibacterial tests for Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Aspergillus niger, Fusarium oxysporum, and Candida albicans. The eye irritation test was performed according to the toxicity testing regulation of the Korea Food & Drug Administration (2009. 8. 24, KFDA 2009-116). After SPS had been applied on the left eye of the rabbits, eye irritation in the cornea, iris and conjunctiva was observed on the 1st, 2nd, 3rd, 4th & 7th day. After SPS had been dropped on bacterial species that cause keratitis, the minimum inhibition concentration and the size of the inhibition zone were measured. The anti-bacterial potency was also measured by taking the size of inhibition zone. Results: After SPS had been administered on the left eye of the rabbits, none of nine rabbits were found to show abnormal signs or weight changes. After SPS had been administered on the left eye of the rabbits, no eye irritation in the cornea, iris and conjunctiva was observed on the 1st, 2nd, 3rd, 4th & 7th day. No specific response was detected in MIC for bacterial species Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Aspergillus niger, Fusarium oxysporum, and Candida albicans after SPS had been applied. Conclusions: This study suggests that SPS is a non-toxic and non-irritant medicine that does not cause any of eye irritation in rabbits, but it has no antibacterial effects on bacterial species that are well known to cause keratitis. These results suggest that more research is required on extracts from herbal medicines for treating keratitis.

• Journal of Applied Biological Chemistry
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• v.57 no.2
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• pp.123-129
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• 2014

The antioxidant and antimicrobial activities of Camellia oleifera seed oil were studied. Four kinds of seed oil samples were prepared, crude oil and refined oil, extracted by cold pressing method (CPC, CPR), and organic solvent extraction (OSC, OSR). Antioxidant activity analysis was measured in 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid)-diammonium salt, ferric reducing Ability of Plasma, and 2,2-diphenyl-1-picrylhydrazyl assays. Besides, the percentage of inhibition of red blood cells hemolysis induced by 2,2'-azobis(2-amidnopropane) dihydrochlorid, the lag time of LDL conjugated dienes formation in vitro, and the inhibitors of loss in tryptophan fluorescence were all used to estimate the antioxidant activity of the samples. The total phenolic contents (TPC) were detemined by Folin-Ciocalteu method. The TPC of the C. oleifera seed oils can be arranged in descending order: CPC ($1.9172{\mu}g/mL$) > OSC ($1.5218{\mu}g/mL$) > CPR ($1.0611{\mu}g/mL$) > OSR ($0.6782{\mu}g/mL$). And the oils were investigated for activity against Escherichia coli, Bacillus subtilis, Saccharomyces cerevisiae and Aspergillus niger. The results showed the antioxidant activity of crude oil by cold pressing method was stronger than others, and all oils did inhibit activity of the top three bacteria expert A. niger. The further significance of the study contributes to measure the antioxidant and antimicrobial activity of the potential health benefits by the different methods of preparation and the oil of C. oleifera seeds acting as free radical scavenger, pharmaceuticals and preservatives may offer some information in medicine and cosmetic not just in food field.

• Journal of the Korean Chemical Society
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• v.65 no.2
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• pp.93-105
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• 2021

Mononuclear Cu(II), Ni(II), Co(II), Mn(II), Zn(II), Fe(III), Ru(III), and UO2(II) complexes of 2-hydroxy-4-(p-tolyldiazenyl)benzylidene)-2-(p-tolylamino)acetohydrazide (H2L) were prepared by direct method. The ligand and its complexes were isolated in solid state and characterized by analytical techniques such as elemental and thermal analyses, molar conductance, magnetic susceptibility measurements and spectroscopic techniques such as UV-Visible, IR, 1H-NMR and 13C-NMR. The spectral data indicated that the ligand acted as neutral/monobasic bidentate or monobasic/dibasic tridentate ligand bonded to the metal ions through the oxygen atom of ketonic or enolic carbonyl group, azomethine nitrogen atom and deprotonated/protonated phenolic oxygen atom forming either tetragonally distorted octahedral or octahedral. Antimicrobial activities of the ligand and its complexes were evaluated against Escherichia coli, Bacillus subtilis and Aspergillus niger by well diffusion method. The results of antifungal activity showed that the Fe(III) complex (10) exhibited higher antifungal against Aspergillus niger than the other complexes. However, the results of antibacterial activity revealed that Cu(II) complex (4) is the most active against Escherichia coli while the Cu(II) complex (5) and Fe(III) complex (10) exhibited higher antibacterial effect on Bacillus subtilis than the other complexes.

• Journal of Food Hygiene and Safety
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• v.38 no.2
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• pp.63-68
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• 2023

In this study, we analyzed the effect of storage conditions on the survival of fungi in red pepper powder. Red pepper powder was inoculated with a total of six fungal species, namely Aspergillus terreus, Aspergillus flavus, Rhizopus microsporus, Aspergillus fumigatus, Aspergillus niger, and Aspergillus ochraceus at a final cell count of 4-6 log CFU/g. After inoculating the sterilized red pepper powder with fungi, we dried the powder on a clean bench and packaged it in zipper bags. Following drying, the water activity was 0.502±0.001. Subsequently, the red pepper powder inoculated with fungi was stored at -20℃, 5℃, 15℃, and 25℃. All six species of fungi perished the quickest at 25℃ and survived for the longest (168 days) at -20℃. In summary, this study showed that fungi survive for an extended period in red pepper powder at -20℃ and 5℃ compared to 15℃ and 25℃. Therefore, to prevent fungal contamination, red pepper powder should have a water activity below 0.6 and be stored in a zipper bag at room temperature.

• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.1
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• pp.71-80
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• 2019

We have been experimenting for industrialize four kinds of wildflowers(Smilax china, Saururus chinensis, Houttuynia cordata and Zizania caduciflora) which are used for Korean medicinal plants for a long time as Korean resources plants. Smilax china, Saururus chinensis, Houttuynia cordata was used for roots and Zizania caduciflora used for leaves. Extraction was carried out in 50% ethyl alcohol, which was concentrated by freezing the material and then injected at a low concentration of 100ppm. The results of the study on the antibacterial potential activity and antifungal potential activity using the four wildflowers strains were as follows. 1. The results of the sterilization and antibacterial potential activity and antifungal potential activity were as follows. Houttuynia cordata showed good inhibitory effect for Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa. The inhibitory power of Zizania caduciflora was proved to some extent. However, other cultivars showed little antibacterial and antifungal activity. 2. The antifungal potential activity against Candida albicans, Aspergillus niger, Aspergillus fumigatus, and Cryptococcus neoformans was small but some inhibition against Candida albicans was confirmed. There was no inhibition of other fungi potential at all.

• Economic and Environmental Geology
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• v.57 no.1
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• pp.25-39
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• 2024

The Téra manganese deposit represents the most significant manganese mineralization discovered in Niger up today. The main host rocks of this ore are gondites, which are a garnet and quartz rich metamorphic rocks. The supergene weathering developed an alteration profile on these gondites. This study aims to identify the mineralogical composition of gondites and associated rocks, in order to highlight the origine of rocks and the manganese enrichment. The methodological approach adopted involved a field study followed by polarizing microscopic analysis using transmitted and reflected lights. Additionally, quantitative X-ray diffraction (XRD) analysis was performed to assess the manganese ore minerals present in the gondite and associated rocks, including mica schists, amphibolites, and quartzites. The petrographic study revealed a paragenesis characterized by the presence of kyanite, staurolites, garnets and plagioclases that are generally poikiloblasts with quartz and opaque minerals inclusions, emphasizing the internal schistosity which is planar, helicitic or microfolded. These features indicate a prograde metamorphism until high-pressure amphibolite facies conditions. These conditions are followed by greenschist facies conditions marked by calcite, epidote, muscovite, chlorite and muscovite assemblage which emphasizes the vertical tectonics. Depending on the alteration process, the manganese ore exhibit a granular texture at the bottom of the gondite hills, transitioning to a colloform texture towards the top, passing through the epigenization and replacement texture. The XRD analysis further revealed that the studied rocks originated from a volcano-sedimentary complex, characterized by alternating marly, arenaceous and pelitic sequences associated with submarine exhalations.

• Nuclear Engineering and Technology
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• v.56 no.5
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• pp.1880-1886
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• 2024

To elucidate the mechanism of damage caused by hyphae and organic acids produced by Aspergillus Niger on the surface and internal structure of uranium ore, direct uranium leaching, indirect uranium leaching and semidirect uranium leaching were conducted, and the surface morphology, strength, mineral crystallinity, porosity, and permeability of the ore were analyzed. The results demonstrated that the combination of biomechanical forces exerted by hyphae and the complexation effects of organic acids led to the dissolution of SiO₂ and other substances on the surface of ore, resulting in exfoliation from the exterior to the interior, thereby promoting uranium recovery. Furthermore, the proton exchange involving H⁺ and the complexation of organic acids resulted in the dissolution of cations within the ore, causing destruction to the crystal lattice structure of minerals and increasing the porosity and permeability inside the ore. The dominant factor contributing to ore damage during recovery was organic acids.