• Mycobiology
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• v.39 no.4
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• pp.278-282
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• 2011

The objective of this study was to find useful fungi with ${\alpha}$-amylase activity from the Korean traditional nuruk for the quality of traditional Korean alcoholic beverage. In this study, 165 samples of traditional nuruk were collected from 170 regions throughout Korea and the fungi were isolated to a total of 384 strains. In order to investigate the effect of microflora on nuruk, ${\alpha}$-amylase activity, saccharogenic power (SP), starch hydrolysis activity and acid producing activity were evaluated. Ten strains were selected by ${\alpha}$-amylase activity, which ranged from 458.47 to 1,202.75 U/g. The size of the discolored zone for the starch hydrolysis activity of each fungus ranged from 0.3 to 2 cm. The SP of the 10 strains ranged from 228.8 to 433.4 SP. Of the 10 stains, three were identified as Aspergillus oryzae, two as Aspergillus flavus, two as Lichtheimia sp., one as Rhizopus oryzae and two as other strains. The total aflatoxins present in the nuruks were examined using enzyme-linked immunosorbent assay. The 10 nuruks had less than 1.11 ppb of aflatoxins.

• Applied Biological Chemistry
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• v.22 no.3
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• pp.135-141
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• 1979

These experiments were conducted to investigate the conditions of the acid protease production by Rhizopus oryzae and the characteristics of crude enzyme. The results obtained were as follows: 1. The optimum culture time and the optimum amount of added water to the wheat bran medium were about 48 hrs and $80{\sim}120%$, respectively. 2. The addition of $(NH_4)_6Mo_7O_{24},\;(NH_4)_2SO_4,\;NH_4NO_3$, casein, and albumin, respectively, as nitrogen sources to the wheat bran medium was effective. Of these, the optimum concentrations of addition of $(NH_4)_6Mo_7O_{24}$ and casein which were the most effective were 0.1% and 1.0%, respectively. 3. The addition of glucose, galactose, maltose, lactose, and soluble starch, respectively, as carbon sources to the wheat bran medium was effective. Of these, the optimum concentration of addition of glucose which was the most effective was 3.0%. 4. The addition of $KH_2PO_4$ as a phosphate salt to the wheat bran medium was effective. The optimum concentration of addition of $KH_2PO_4$ was 0.3%. 5. The optimum pH for the enzyme action was 2.4, the optimum temperature about $40^{\circ}C$, and the stable pH range $2.0{\sim}5.0$. The enzyme was stab1e below $40^{\circ}C$. 6. The enzyme activity increased rapidly for 10 minutes after addition, thereafter it increased slowly. 7. The enzyme activity increased rapidly to 2 ml of addition, but nearly did not increase at the amounts greater than 2ml.

• The Plant Pathology Journal
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• v.23 no.2
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• pp.113-115
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• 2007

A kind of naphthoquinone, plumbagin was purified and identified from the leaves of Nepenthes $ventricosa\;{\times}\;maxima$ through solvent extraction, silica gel column chromatography, and recrystallization. The yield (0.51%) was higher than that of the root of Plumbago scandens (0.26%), P. capensis (0.15%), and N. thorelii (0.092%). It exhibited antifungal activity against all plant pathogenic fungi tested, Alternaria alternata, Aspergillus niger, Bipolaris oryzae, Fusarium oxysporum, Phytophthora capsici, Rhizoctonia solani, Rhizopus stolonifer var. stolonifer and Sclerotinia sclerotiorum. The minimum inhibitory concentration values ranged from about 4.8 to $56.6\;{\mu}g/ml$ against the above eight fungi and R. solani was the most sensitive.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.6
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• pp.1230-1238
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• 1999

To identify antimicrobial activities of soybean paste, studies have been carried out with laboratory manufactured soybean paste, traditional and improved type soybean paste purchased on the market. The soybean paste fermented with Aspergillus oryzae and Rhizopus tamari and commercial soybean paste were shown antimicrobial activities for Bacillus cereus, Escherichia coli, Listeria monocytogenes, Staphy lococcus aureus, Streptococcus faecalis, Escherichia coli O157:H7, Bacillus subtilis and Salmonella typhimurium. Non fermented soybean paste did not show antimicrobial activities against Bacillus cereus, Escherichia coli, Listeria monocytogenes, Staphylococcus aureus and Streptococcus faecalis. The extract of soybean paste extracted by 80% methanol showed the highest antimicrobial activities of in ethyl acetate fraction and followed butanol fraction, respectively. Antimicrobial activities of traditional and improved type soybean paste were shown against all tested microorganisms and clear zone length of traditional soybean paste was slightly larger than that of improved type. Components of antimicrobial fractions of soybean paste were guessed peptides, 4 hydroxy benzoic acid, benzoic acid by GC MS.

• 한국생태학회:학술대회논문집
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• 2002.08a
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• pp.93-100
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• 2002

Dynamics of certain $N_2$fixing bacteria such as Rhizobium, Azospirillum and Azotobactor, nodule number in dominant legume, Atylosia trinervia, P-solubilizing bacteria, actinomycetes and fungi were studied in unburned and burned site of natural grassland, southern India. Population of $N_2$- fixing bacteria, P-solubilizing bacteria, fungi and nodule number in legume increased significantly in burned sites. On the other hand, the actinomycetes population remained unchanged. Thirty six species of fungi with tricalcium phosphate solubilizing ability were recorded. The most efficient P-solubilizing fungi recognised in the soils of the study sites are Absidia ramosa, Gongronella butlerii, Mortieralla spinosa, Mucor racemosus, Rhizopus nigricans, R. stolonifer, R. oryzae, Aspergillus fumigatus, A. nidulans, A. niger Theilavia terricola and Cheatomium lunasporium.

• Mycobiology
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• v.33 no.4
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• pp.210-214
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• 2005

More than 120 isolates of lactic acid bacteria obtained from Kimchi was screened for antifungal activity against Aspergillus fumigatus. Approximately 10% of the isolates showed inhibitory activity and only 4.16% (five isolates) exhibited strong activity against the indicator fungus A. fumigatus. The five isolates showed a wide rang of antifungal activity against A. flavus, Fusarium moniliforme, Penicillium commune, and Rhizopus oryzae. They were identified by 16S rDNA sequencing as Lactobacillus cruvatus, L. lactis subsp. lactis, L. casei, L. pentosus, and L. sakei. The effect of Lactobacillus on mycelial growth and fungal biomass as well as its ability to produce toxic compounds were determined. The results indicate that the three species, Lactobacillus casei, L. lactis subsp. lactis, and L. pentosus, are active against A. fumigatus.

• Journal of Microbiology and Biotechnology
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• v.17 no.4
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• pp.650-654
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• 2007

In our previous work, a method of pretreating lipase was developed to prevent loss of its activity during covalent immobilization. In this study, Rhizopus oryzae lipase was pretreated before immobilization and then immobilized on a silica gel surface. The effects of the various materials and conditions used in the pretreatment stage on the activity of immobilized lipase were investigated. Immobilized lipase pretreated with 0.1% of soybean oil had better activity than those pretreated with other materials. The optimal temperature, agitation speed, and pretreating time for lipase pretreatment were determined to be $40^{\circ}C$, 200rpm, and 45min, respectively. The activity of immobilized soybean oil pretreated lipase was 630U/g matrix, which is 20 times higher than that of immobilized non-pretreated lipase. In addition, immobilized lipase activity was maintained at levels exceeding 90% of its original activity after 10 reuses.

• The Korean Journal of Ecology
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• v.25 no.4
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• pp.227-234
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• 2002

Dynamics of certain $N_2$ fixing bacteria such as Rhizobium, Azospirillum and Azotobactor, nodule number in dominant legume, Atylosia trinervia, P-solubilizing bacteria, actinomycetes and fungi were studied in unburned and burned site of natural grassland, southern India. Population of $N_2$ - fixing bacteria, P-solubilizing bacteria, fungi and nodule number in legume increased significantly in burned sites. On the other hand, the actino-mycetes population remained unchanged. Thirty six species of fungi with tricalcium phosphate solubilizing ability were recorded. The most efficient P-solubilizing fungi recognised in the soils of the study sites are Absidia ramosa, Gongronella butlerii, Mortieralla spinosa, Mucor racemosus, Rhizopus nigricans, R. stolonifer, R. oryzae, Aspergillus fumigatus, A. nidulans, A. niger, Theilavia terricola and Cheatomium lunasporium.

• Journal of Food Hygiene and Safety
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• v.24 no.3
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• pp.262-266
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• 2009

Antifungal activity of seven natural antimicrobials, such as $\varepsilon$-polylysine, extract of Yucca shidigera, TLS (vitamin B1 derivative), BMB-FS, chitooligosaccharide, KDSP 001, and KDSP 002 were investigated for their applications in functional beverage. Five fungi including Aspergillus niger, Penicillium citrinum, Rhizopus oryzae, Fusarium moniliforme, and Mucor rouxii were applied as test fungi and mininum inhibitory concentrations (MICs) of antimicrobials were examined. TLS exhibited the strongst antifungal activity among tested antimicrobials and the growth of all fungi was inhibited at 100 ppm. The antifungal activity of BMB-FS appeared different. The growth of Fusarium moniliforme was inhibited by BMB-FS at 100 ppm, but it exhibit antifungal activity on P. citrinum, and M. rouxii at 1000ppm. MICs of TLS appeared to be 60 ppm for four test fungi except A. niger (100 ppm). These results indicate the possible usage of TLS and BMB-FS as natural antimicrobials in functional beverage.

• Journal of Life Science
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• v.22 no.1
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• pp.110-116
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• 2012

Nuruk plays a significant role in the flavor and quality of Takju and Yakju, which are produced through saccharification and alcohol fermentation by various microorganisms. In this study, we identified microbial strains isolated from a plate count and PCR-denaturing gradient gel electrophoresis (DGGE) analysis targeting the 16S and 28S rRNA genes, in order to characterize bacterial and fungal diversity in Sansung Nuruk. The numbers of bacteria and fungi in Nuruk were $1.5{\times}10^9$ CFU/g and $2.2{\tims}10^8$ CFU/g, respectively. The 16S rRNA gene sequence indicated that the predominant bacteria in the isolates and PCR-DGGE profile of Nuruk were Kocuria spp., Pantoea spp., Lactobacillus spp., Pediococcus spp., Weissella spp., Staphylococcus spp., endophytic bacterium, uncultured Gamma-proteobacteria, uncultured Cyanobacteria, and Actinobacteria. Dominant bacteria from the PCR-DGGE profile were Pediococcous pentosaceus and uncultured Cyanobacteria. The 28S rRNA gene sequence indicated the predominant fungi in the isolates and PCR-DGGE profile to be Trichomonascus spp. Pichia spp., Torulaspora spp., Wickerhamomyces spp., Sacharomycopsis spp., Lichtheimia spp., Mucor spp., Rhizopus spp. Aspergillus spp., and Cladosporium spp. Dominant fungi from the PCR-DGGE profile were Pichia kudriavzevii and Aspergillus oryzae. The PCR-DGGE technique was used for the first time in this study to assess a microbial community in Nuruk and proved to be an effective protocol for profiling microbial diversity.