• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.6
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• pp.987-994
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• 2000

Aspergillus coreanus NR 15-1, Asp. oryzae NR 15-3 and Asp. oryzae NR 2-5 isolated from traditional Korean nuruk were screened as parental strains producing starch hydrolyzing enzymes. They were mutagenized by N-methyl -N'-nitro-N-nitrosoguanidine (NTG) and mutants were isolated for analysis of various amylase activities and the ability of acid production. Among them, the mutants harboring high saccharogenic activity, dextrinogenic activity, and the ability of acid production were selected. Fifteen, six, and five strains of mutants were isolated from Asp. coreanus NR 15-1, Asp. oryzae NR 2-5, and Asp. oryzae NR 15-3, respectively followed by NTG mutagenesis. Among these mutants, thirteen strains were identified as auxotrophic mutants. \ulcorner (Arg.￣) mutant from Asp. coreanus NR 15-1 showed high glucoamylase activity and total acid productivity. Z6 (Ade.￣) mutant from Asp. oryzae NR 2-5 showed the highest $\alpha$-amylase activity, therefore \ulcorner and Z6 mutant were selected.

• The Korean Journal of Food And Nutrition
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• v.9 no.4
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• pp.398-403
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• 1996

To produce low salt fermented anchovy by an accelerated method with Asp. oryzae and Bacillus sp. koji and taste properties after the 60 day fermentation were examined. The main free amino acids of 60 day fermented anchovy paste were valine, isoleucine, proline, alanine, lysine, glutamic acid and aspartic acid. Total amount of free amino acids was the highest in non koji anchovy paste wit 2,624.76mg%. Among the koji added samples, Asp. oryzae koji added on was the highest in the amount o free amino acids. Hypoxanthine accounted for 84.14~95.4% of total nucleotides and their related compounds; Asp. oryzae koji added anchovy paste was the highest in nucleotides other related. Citric acid and lactic acid accounted for 94.9~96.7% of total non-volatile organic acids; Asp. oryzae koji added sample was the highest in non-volatile organic acids with 287.93mg%. The Hunter a and b values gradually increased during the fermentation, but the L value decreased until day 30 or 40 and increased steadily after that. The a and b values were higher in the use of Asp. oryzae koji than in Bccillus sp. koji, but the L value was to the contrary. The Asp. oryzae koji added anchovy paste was good in the aspect of color and taste compared to others. In the aspect of odor, the anchovy paste using the mixture of Asp. oryzae and Bacillus sp. koji was the best. Overall aceptability of sensory evaluation was higher in the mixture of Asp. oryzae and Bacillus sp. koji tan in the others.

• Korean Journal of Microbiology
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• v.6 no.3
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• pp.81-86
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• 1968

1. Amylolytic enzyme activities of Asp. oryzae and Asp. oryzae var. fulvus using the glucose as the carbon sources increased remarkably according to the decrease of the residual sugars. 2. The amylase productions of Asp. oryzae and Asp. oryzae var. fulvus were increased and enhanced when the organisms lave belen cultured in modified Koji media containing maltose as adaptive substrate. However, being devoid of maltose the level of amylase activities were lower and the begining of the production was prolonged. 3. The effects of C-sources on the amylase production of them were observed. The level of amylase activity varied with C-sources and their concentrations Marked increase of amylase production was afforded by starch and maltose. The effects of citric acid and tartaric acid were little or nothing. 4. Using the sucrose and lactose as the adaptive substrates both strains show the maximum amylolytic enzyme activities at the 3% concentrations of those sugars.

• Applied Biological Chemistry
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• v.35 no.5
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• pp.351-360
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• 1992

In order to improve the qualities of Doenjang were investigated on the enzyme activity in the koji and changes in chemical composition, flavors and sensory envaluation of Doenjang which were prepared with Rh. delemar koji, Asp. oryzae koji and traditional Meju with mixed koji and soybean as the ratio of optimum mixture. Asp. oryzae koji was indicated highest activities ${\alpha}$ and ${\beta}-amylase$ as 312 mg/ml, 235 mg/ml while Rh. delemar the lowest activities as 16 mg/ml, 38 mg/ml in aging for 40 days amino type ntrogen was the highest in the Asp. oryzae and Rh. delmear mixture koji(D group), Asp. oryzae(A group), and Asp. oryzae koji and Rh. delemar koji(C group) as 460 mg%, 440 mg% and 426 mg% in aging for 40 days. The main flavor components of Doenjang were detected as fellows phenol-2-kmethoxy, 4H-pyran-4-one-3-hydroxy-2-methyl, benzenthanol, 1-octan-3-ol, tetra-methyl pryrazine, 1,3,6 cyclooctatrien. Asp. oryzae(A) and Asp. oryzae koji with Rh. delemar koji mixture(C), group were the most excellent in taste, flavor color for fermented Doenjang at 40 days.

• Korean Journal of Microbiology
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• v.6 no.1
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• pp.6-11
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• 1968

Through the present experiment the various Aspergilli have been isolated from 53 Meju specimens (fermented soy bean cake) which were collected from 43 local areas in Korea and those of them are arranged as 6 different groups: Asp. flavus-oryzae group (38 strains), Asp. niger group (11 strains) Asp. nidulans group (5 strains), Asp. clavatus group (4 strains), Asp. fumigatus group (3 strains), and Asp. ochraceus group (2 strains), as the result of identification of them by the group key of Thom and Raper. Further identifications of them according to the species keys of Thom and Raper, Yamata and Sakakuchi have been also conducted and the results obtained are following as: 1. Group members (38) of Asp. flavus-oryzae group are identified as. Asp. oryzae, Asp. oryzae var. fulvus, Asp. flavus. and Asp. parasiticus, not identified two different strains belong to this group. 2. Group members (11) of Asp. niger group are identified as Asp. niger and Asp. phoenicus. 3. Group members (5) of Asp. nidulans groups are identified as the same species, Asp. nidulans. 4. Group members (4) of Asp. clavatus group are identified as the same species, Asp. clavatits. 5. Group members (3) of Asp. fumigatus group are identified as the same species, Asp. fumigatus. 6. Group members (2) of Asp. ochraceits group are identified as the same species, Asp. sulphereus.

• Applied Biological Chemistry
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• v.32 no.3
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• pp.295-302
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• 1989

This study was carried out as a preliminary test to investigate the improvement of soysauce and soybean paste for natural food. The soybean was treated on raw, soaked, roasted, and steamed condition and it was maked that rice koji was inoculated by Asp. oryzae, Asp. niger, Asp. awamori and on natural condition fermented. They were maked raw soybean-soypaste $(S_0)$, soaked soybean-soypaste $(S_1)$, roasted soybean-soypaste $(S_2)$, and steamed soybean-soypaste $(S_3)$ from soybean (60%), rice koji (30%) and salt (10%) respectively in order to investigate the changes of enzymes activity(amylase, protease, lipase and lipoxygenase activity) during fermentation of them. The results obtained were summarized as follows; Amylase activity was in the order of natural fermented microorganisms>Asp. oryzae>Asp. awamori>Asp. niger in the microorganisms, and $S_0>S_1>S_2>S_3$ in the soybean treatments. Protease activity was in the order of natural fermented microorganisms>Asp. niger>Asp. oryzae>Asp. awamori in the microorganisms, and $S_3>S_2>S_1>S_0$ in the soybean treatments. Lipase activity was a similar tendency in the microorganisms, but it was in the order of $S_0>S_1>S_3>S_2$ in the soybean treatments. Lipoxygenase activity was in the order of natural fermented microorganisms>Asp. oryzae>Asp. awamori>Asp. niger in the microorganisms, and $S_0>S_1>S_3>S_2$ in the treatments.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.2
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• pp.69-76
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• 1990

To substitute the soy-sauce 'koji' used in fish sauce processing with molded sardine meal(MSM) 'koji', the culture conditions of MSM be inoculated with Aspergillus spp. were investigated. To prepare the MSM, Asp. awamori(KFCC. 11439), Asp. guercinus (KFCC. l1595), Asp. niger(KFCC. 11239), Asp. oryzae(KFCC. 32343), and Asp. sojae(KFCC. 11559) were inoculated upon the chopped sardine with $20\%$ (w/w) corn starch after steriling it at $121^{\circ}C$ for 15min. Sporulation time cultured with Asp. spp. at $30^{\circ}C$ was 48hrs and color of mycelium on the surface of MSM inoculated with Asp. awamari and Asp. oryzae were black, that of MSM inoculated with the other strains were yellowish brown. The activity of protease and lipase from the MSM were increased till the 72hrs of culture at $30^{\circ}C$, while the content of trimethylamine was decreased after 96hrs of culture period at same condition with exception of Asp. niger. Asp. oryzae and Asp. sojae showed superior in pro-tease and lipase activity in comparison with the other strains, and maximum activity of protease and lipase of MSM was observed after 72hrs of culture period. The optimum pH and temperature for the activity of MSM inoculated with Asp. oryzae and Asp. sojae were pH 9.0, $30\~35^{\circ}C$ and pH $6\~7$, $35^{\circ}C$, respectively.

• Applied Biological Chemistry
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• v.21 no.2
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• pp.123-130
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• 1978

Asp. oryzae D and H strains were cultured in the wheat bran and Czapek-Dox liquid media containing garlic powder in order to investigate the effect of garlic on the enzyme production and growth of Asp. oryzae. The results obtained were as follows; 1. Wheat bran media containing 0.5 to 2% garlic powder yielded increased in acid protease activity of the Asp. oryzae D strain while the best activity appeared at 2 to 6% in alkaline protease and 0.5% in neutral protease. 2. The protease activities of Asp. oryzae H strain was similar to that of the control in wheat bran media containing 0.5 to 8% garlic powder, but the peak appeared at the garlic powder concentration of 30%. 3. Garlic powder increased the $\alpha$-and Glucoamylase activities of Asp. oryzae H strain. 4. Garlic powder inhibited the both Asp. oryzae strains from the cellulase production. 5. Czapek-Dex liquid media containing 0.5 to 6% garlic powder yielded increase in dry mycerial weight in comparison with the control, and the increament was much more in case of the Asp. oryzae H strain. 6. As the amount of the garlic powder added to the Czapek-Dox liquid media increased, the pH of the cultured media of Asp. oryzae D strains was on the decrease while the media of H strain increased. 7. As the amount of the garlic powder added increased, the acidity of the cultured Czapek-Dex media increased. 8. The growth rate of the two Asp. oryzae strains were remarkably inhibited and no growth appeared in wheat bran and Czapek-Dox media containing garlic powder more over 10%. 9. The utility rate of reducing sugar was the highest in the Czapek-Dox liquid media containing 1 to 2% garlic powder.

• Korean Journal of Food Science and Technology
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• v.9 no.3
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• pp.205-210
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• 1977

From samples of red pepper powder sold in Korea were isolated and identified 13 species of molds (Aspergillus amstelodami, Asp. chevalieri, Asp. clavatus, Asp. flavus, Asp. janus var. effusus, Asp. oryzae, Asp. oryzae var. brevis, Asp. repens, Asp. sydowi, Asp. thomii, Asp. tubingensis, Penicillium thomii, Scopulariopsis brevicaulis) and 5 species of bacteria (Bacillus pumilus, Bac. subtilis, Micrococcus luteus, M. varians, Staphylococcus aureus). Radiosensitivity of these microorganisms was examined to give $D_{10}$ values of $14{\sim}41\;krad$ for molds, $11{\sim}24\;krad$ for bacterial vegetative cells and $190{\sim}250\;krad$ for bacterial spores. The red pepper powder was contaminated with $2{\sim}3{\times}10^2$ mold counts/g and $3{\sim}6{\times}10^7$ bacterial counts/g, which would be sufficiently destroyed by irradiating 200 krad ${\gamma}-rays$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.15 no.4
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• pp.1-9
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• 1986

The mashes of soybean paste were preparea using the conventional meju fermented naturally by wild microoganisms or the new types of meju fermented by pure cultures of Aspergillus oryzae, Bacillus natto and B. subtilis to elucidate changes during the aging period. The results obtained are as follows ; The soybean paste made with conventional meiu and Asp. oryzae meju showed higher content of amino nitrogen than those of B, natto and B. subtilis meju. Soybean paste made with conventional meju contained a little more content of total and reducing sugars than other soybean pastes. ph during aging period was higher than 5.0 for the Asp. oryzae paste while less than 4.5 for B. subtilis paste. Aspartic acid. threonine, serine, glutamic acid, glycine, alanine, cystine, valine, methionne, leucine and histidine for Asp. oryzae paste ; tyrosine, arginine and proline for conventional meju paste; and isoleucine and phenylalanine for B. subtilis paste were found to be peak amount 90 days after the preparation. The content of total free amino acid was high in the order of Asp. oryzae paste, conventional paste, B. natto paste and B. subtilis paste.