• Korean Journal of Agricultural Science
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• v.24 no.2
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• pp.283-289
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• 1997

CNU O4-5 isolated from conventional Meju, which is used as raw material for making a soybean fermentation food, identified as an Aspergillus oryzae. To make koji, Aspergillus oryzae CNU O4-5 was cultured for 3-4 days at $30^{\circ}C$ with various grain materials such as flour, soybean powder, flour+soybean powder(1:1), soaked soybean and rice. The koji was evaluated for analyze the angiotesin converting enzyne(ACE) inhibition, antioxidative activity, superoxide dismutase(SOD) activity, amylase and protease activity. $\alpha$-amylase and glucoamylase activities of flour koji were higher than those of the koji soybean powder. However neutral and alkaline protease activities of flour koji were lower than those of flour+soybean powder and soybean koji. Amylase and protease activities of kojies of soaked soybean and rice showed very low level. The range of the ACE inhibition rate by hot water fraction of the kojies, which are cultured with various gain materials, were from 45% to 54%. The anti oxidative activity of ethanol-fraction of koji, which is made by using the soybean powder or soaked soybean, prolonged for 6 days in lard at $60^{\circ}C$. The SOD activity of grinded fraction of koji, which is made by using the flour or soybean powder, was same as 2,000 units per g of each koji.

• The Korean Journal of Mycology
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• v.42 no.3
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• pp.191-200
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• 2014

Nuruk samples collected from various regions in Korea were investigated in terms of fungal contents and diversity. In measurement of colony forming unit (CFU) in Nuruk suspensions on DRBC agar, Nuruk samples MS4, MS8, and MS10 were among the highest fungal density, with $1,278.9{\pm}21.6$ (${\times}10^4$), $1,868.0{\pm}27.7$ (${\times}10^4$), and $775.1{\pm}19.2$ (${\times}10^4$) were among the samples showing the highest fungal density. CFU per 20 mg Nuruk, respectively. The majority of fungal components were yeasts, including Pichia anomala, P. kudriavzevii, Kluyveromyces marxianus, and Saccharomycopsis fibuligera, whereas Aspergillus oryzae and Rhizopus oryzae, the representative Nuruk fungi, were predominant only in the low fungal density Nuruks (MS2, MS5, and MS11). Saccharification capability of the fungal isolates was assessed by measurement of amylase activity in the culture broth. The highest amylase activity was found in A. niger and A. luchuensis, followed by S. fibuligera. A. oryzae and R. oryzae showed fair amylase activity but significantly lower than those of the three fungal species. R. oryzae was suggested to play an additional role in degradation of ${\beta}$-glucan in crop component of Nuruk since R. oryzae was the only fungus that showed ${\beta}$-glucanase activity among the fungal isolates. To confirm the safety of Nuruk, aflatoxigenicity of the isolated Aspergillus was estimated using the DNA markers norB-cypA, aflR, and omtA. All of the isolates turned out to be non-aflatoxigenic as evidenced by the deletion of gene markers, norB-cypA and aflR, and the absence of aflatoxin in the culture supernatants shown by TLC analysis.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2003.06a
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• pp.69-74
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• 2003

• Journal of Microbiology
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• v.39 no.2
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• pp.95-101
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• 2001

In an effort to develop an efficient expression and secretion system for heterologous proteins in Aspergilius nidulans, the PCR-amplified coding sequence for alkaline pretense (AlpA) of A. oryzae was cloned into a fungal expression vector downstream of A. nidulans aicA (alcohol dehydrogenase) promoter to yield pRAAlp. Transformation of A. nidulans with pRAAlp gave stable transformants harboring various copy numbers (3 to 10) of integrated alpA gene, from among which 6 representatives were selected. On a medium containing 0.8% ammonium sulfate that represses the expression of the host's own pretense, the alcA prumoter-controlled AlpA expression was strongly induced by threonine but repressed by glucose. The level of AlpA secretion was highest (approximately 666 mU/ml) in transformant ALP6 containing the largest copy number integrated alpA. However, the level of AlpA secretion was not necessarily proportional to the copy numbers of the integrated alpA genes. The N-terminal sequence or the secreted mature AlpA was determined to be Gly-Leu-Thr-Thr-Gln-Lys-Ser and its molecular mass to be approximately 34 kDa, indicating that AlpA is properly processed by the removal of 121 N-terminal amino acids.

• Applied Biological Chemistry
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• v.29 no.3
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• pp.255-259
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• 1986

The aflatoxin production by Aspergillus ATCC 15517 decreased in the mixed culture with Aspergillus awamori, Aspergillus kawachii, Aspergillus niger, Aspergillus oryzae, or with Aspergillus shirousamii to 1.3%, 13.8%, 1.3%, 0.7%, or 38.5% of that of monoculture respectively. These koji molds degraded $75%{\sim}100%$ of added aflatoxin $B_1\;(791{\mu}g/50ml\;YES medium)$. A. awamori secreted during growth aflatoxin degrading factor(s) which was heat-labile. The degraded aflatoxin by the factor(s) showed no toxicity against Bacillus megaterium NRRL B-1368.

• Food Science and Preservation
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• v.20 no.3
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• pp.379-385
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• 2013

To establish the optimal manufacturing conditions of soybean koji, soybean Koji prepared with Aspergillus oryzae 6-M-1 and Bacillus subtilis 3-B-1 isolated from traditional Korean meju. During 7 days of making Koji, the amount of amino-type nitrogen was getting more increase. The amount of amino-type nitrogen of Koji prepared with A. oryzae 6-M-1 was 686.16 mg% (w/w), that of Koji with B. subtilis 3-B-1 was 643.46 mg% (w/w) at seventh day of making Koji. The ${\alpha}$-amylase activity of Koji prepared with A. oryzae 6-M-1 was 1472.54 unit/g, that of Koji with B. subtilis 3-B-1 was 791.00 units/g on the seventh day of the making. The acidic protease activity of Koji prepared with A. oryzae 6-M-1 was 309.00 unit/g, that of Koji with B. subtilis 3-B-1 was 135.88 unit/g at 7th day of making. The amount of amino-type nitrogen and enzyme activities of soybean Koji prepared with A. oryzae 6-M-1 and B. subtilis 3-B-1 were produced more than those of wheat flour Koji made in factory. Sensory evaluation on a commercial doenjang and doenjangs prepared with A. oryzae 6-M-1 and B. subtilis 3-B-1 was not significantly different at p<0.05.

• Korean Journal of Food Science and Technology
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• v.49 no.3
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• pp.286-295
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• 2017

This study was performed to develop a liquid flavoring material from Tenebrio molitor larva by using Aspergillus oryzae. T. molitor with 1% A. oryzae for 48 hours yielded the highest protease activity. Different salt concentrations and rice flour addition affected the fermentation characteristics for 90 days. LN (low salt, rice flour non-addition) yielded high protease activity, and total nitrogen and amino-type nitrogen contents. LN showed Glu accounting to 15.16% of the free amino acids and yielded high scores of sweet and savory taste, and overall acceptance after 90 days. Rice flour addition group showed high content of total and reducing sugars with high amylase activity, however, low salt concentration had more effect on sensory acceptance than rice flour addition had (p<0.05). All samples had total acidity <1% and LN (90) showed the highest browning index and aroma intensity, as noted from maillard reaction, as well as good sensory acceptance.

• Korean Journal of Agricultural Science
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• v.13 no.2
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• pp.279-288
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• 1986

One hundred and fifty one mutant strains were obtained from the parent strain Aspergillus oryzae MF by ultra-violet ray irradiation. Among those mutants a strain, Asp. oryzae UM-36 which hyperprodued protease, was selected and its morphological characteristics and the production of enzymes protease, ${\alpha}$-amylase, and glucoamylase on wheat bran koji and on soy-sauce koji were studied. The results obtained were as follows 1. The selected mutant showed slower growth and weak sporulation on malt agar and on Czapek agar than the parent strain. 2. The conidiophores of the mutant were generally shorter than those of the parent when grown on malt agar. 3. Sectoring in colonies was not found when grown on malt agar and on Czapek agar. 4. The level of protease production by the mutant was increased approximately 1,4-fold higher on wheat bran koji and 2-fold higher on soysauce koji than by the parent. 5. The production of ${\alpha}$-amylase and glucoamylase by the mutant were also increased as compared with the parent on wheat bran koji and on soy sauce koji. 6. In the case of parent strain and mutant strain, the highest activity of protease appeared after three days in wheat bran medium at $30^{\circ}C$ incubation, but the highest activities of ${\alpha}$-amylase and glucoamylase appeared after two days.

• Food Science and Preservation
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• v.23 no.1
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• pp.117-126
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• 2016

This study was performed to provide information for improving the quality characteristics of tangerine peel Soksungjang. Tangerine peel Soksungjangs were prepared with 10% tangerine peel powder by addition of different koji such as Rhizopus oligosporus (RS, RTS) and Aspergillus oryzae (AS, ATS). As a result, the moisture content was not changed and crude protein content decreased during fermentation in all samples. The pH of RS (Soksungjang manufactured with Rhizopus oligosporus koji) and RTS (Soksungjang manufactured with Rhizopus oligosporus koji and 10% tangerine peel powder) was not changed, whereas pH of AS (Soksungjang manufactured with Aspergillus oryzae) and ATS (Soksungjang manufactured with Aspergillus oryzae koji and 10% tangerine peel powder) decreased rapidly after 10 days of fermentation. The acidity values of all the samples increased during fermentation. The major free sugars were glucose, fructose, and maltose; while, the major organic acids were citric acid, succinic acid, acetic acid, and lactic acid in all the samples. The amino nitrogen content and protease activity were highest in the AS and ATS. Conversely, the reducing sugar content and ${\alpha}$-amylase activity were highest in the RS and RTS. The major free amino acids in all samples were glutamic acid, lysine, leucine, and arginine. Sixty kinds of volatile flavor compounds were identified from all samples; the majority of which were 21 alcohols, 14 hydrocarbons, 5 esters, and others identifies as acids, ketones, and aldehydes.

• Journal of Life Science
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• v.22 no.12
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• pp.1704-1711
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• 2012

Three mold strains, Aspergillus oryzae (A. oryzae), Aspergillus kawachii (A. kawachii), and Monascus purpureus (M. purpureus), were tested for fermentation of Acanthopanax senticosus (A. senticosus) leaf, root, stem, and fruit powders. The fermented A. senticosus materials were then tested for bioactive materials (phenolic compounds, flavonoids, mineral and fatty acid) and biological activities (DPPH free radical scavenging activity, reducing power, and tyrosinase inhibition activity). The highest concentrations of phenolic compounds and flavonoids were NFASL at 4.11% and MPASL at 2.30%, respectively. Major minerals were Ca, K, Mg and Mn. Major fatty acids in fermented A. senticosus powders were palmitic, linolenic, and stearic acids. DPPH radical scavenging activity was slightly stronger in non-fermented than in fermented A. senticosus. Tyrosinase inhibition activity was stronger in fermented A. senticosus than in NFAG. The Fe/Cu reducing powers were stronger in non-fermented A. senticosus than in any of the fermented A. senticosus materials. Overall, the study provides basic data for understanding the biological activities and chemical characteristics of A. senticosus fermented by molds for the development of functional foods.