• Korean Journal of Food Science and Technology
• /
• v.36 no.1
• /
• pp.81-85
• /
• 2004

Quality characteristics of kochujang made with Aspergillus oryzae-and/or Cordyceps sp.-inoculated koji were investigated. Protease activity of Cordyceps sp.-inoculated koji was higher than that of A. oryzae-inoculated one. Sensory evaluation showed that kochujang made with mixture of A. oryzae-and Cordyceps sp.-inoculated koji (70 : 30, w/w) was superior to others.

• Microbiology and Biotechnology Letters
• /
• v.44 no.1
• /
• pp.40-47
• /
• 2016

This study was conducted to evaluate the possible utility of 3 Aspergillus oryzae strains (designated as SCF-6, SCF-37, and JJSH-1), isolated from Korean traditional fermented materials, as starter cultures in the soybean paste industry. Doenjang (fermented soybean paste) was made with the A. oryzae strains described above, and its quality attributes were analyzed during a 60-day aging period. No significant differences in pH, moisture, or salt content were detected among the doenjang varieties made with the 3 Aspergillus strains. The concentration of amino-nitrogen, an indicator of doenjang aging, increased in each sample during the aging period. After the 60-day aging period, the contents of amino-nitrogen and free amino acid in doenjang made with SCF-6 showed the highest concentrations among the tested doenjang products: 971.6 and 8,064.9 mg%, respectively. Measurements of the color of doenjang showed that lightness and yellowness decreased during the aging period, but redness increased. After the 60-day aging period, the ${\gamma}$-aminobutyric-n-acid (GABA) concentrations in doenjang made with SCF-6 and SCF-37 were 61.3 and 53.7 mg%, respectively. In doenjang samples, aflatoxin was not detected and the concentrations of biogenic amines (histamine and tyramine) were 2.55-5.60 mg/kg and 3.70-5.87 mg/kg, respectively. These results indicated that A. oryzae SCF-6 isolated from traditional fermented foods could be useful as a starter culture in the soybean paste industry.

• Microbiology and Biotechnology Letters
• /
• v.39 no.4
• /
• pp.357-363
• /
• 2011

This study focus was primarily the development of liquid starters for Aspergillus oryzae and Aspergillus niger prepared with wheat bran as a low cost culture medium. For the preparation of the liquid media wheat bran was added at rates of 0, 5, 10, 15 and 20% and the Aspergillus sp. strains were then inoculated to these prepared broths. The results indicated that the more that wheat bran was contained in the medium, the more mycelia was produced for A. oryzae and A. niger. The highest enzyme activities were obtained with a 10~15% adding rate of wheat bran for both strains. Changes in the enzyme activities of the liquid starters during various incubation times (0, 24, 48, 72 and 96 hrs), indicated that the highest enzyme activities were seen between 48 and 72 hrs of culture. In addition, a comparative study was carried out on the production of enzymes using wheat as a substrate in nuruk, with liquid starter made from fermented agents according to the same concentrations used with the wheat bran. The pH, acidity, amino acidity, reducing sugar content and enzyme activity (${\alpha}$-amylase, glucoamylase, acidic protease) of wheat nuruk made with liquid starter were compared with those of wheat nuruk made with solid starter. The results suggest that the liquid starter is superior in both cases.

• Journal of Applied Biological Chemistry
• /
• v.57 no.3
• /
• pp.197-203
• /
• 2014

Various parameters such as solvent selection, concentration, solid/liquid ratio, soaking time, temperature, stationary, shaking conditions, and repeated extractions were investigated in order to determine the optimum extraction conditions of ${\beta}$-glucosidase from bagasse fermented by mixed culture of Aspergillus niger NRC 7A and Aspergillus oryzae NRRL 447. Among various solvents tested, non ionic detergents gave the best results than the inorganic or organic salt solutions and distilled water. The optimum conditions for extraction of ${\beta}$-glucosidase were 30 min soaking time at $40^{\circ}C$ under shaking condition at 150 rpm, with solid/liquid ratio 1:15 (w/v), which yielded $2882.74{\pm}95.52U/g$ fermented culture (g fc) of enzyme activity. With repeated washes under the above optimum conditions, the results showed that enzyme extracted in the $1^{st}$ and $2^{nd}$ washes represents about 90% of the total activity.

• Mycobiology
• /
• v.28 no.3
• /
• pp.119-122
• /
• 2000

Phytases (myo-inositol hexakisphosphate phosphohydrolase; EC 3.1.3.8) are enzymes which catalyze the hydrolisys of phytate into myo-inositol and inorganic phosphates. Phytases are found in plants and a variety of microorganisms. Aspergillus species were treated with 254 nm of UV irradiation for the screening of phytase overproducing mutant strains. At 15 minute irradiation, the survivals of population were less than 5%, and UV irradiation time was decided at 20 minute for the isolation of mutant strains. Four UV mutant strains in A. oryzae (YUV-47, -169, -341, -511) and six in A. ficuum (FUV-17, -36, -69, -193, -317, -419) were isolated on PSM media containing ammonium phosphate. The specific enzyme activities of A. ficuum mutants are 110 to 140% higher than that of wild type.

• YAKHAK HOEJI
• /
• v.16 no.2
• /
• pp.97-107
• /
• 1972

Thirty-three Mannich bases of 2,2'-methylene bis(3,4,6-trichlorophenoxyacetic acid) were synthesized as potential antimicrobial agents and tested against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Trichophyton rubrum, Microsporum gypseum, Epidermophyton floccosum, Aspergillus niger and Aspergillus oryzae in vitro. It was found that: 1) Compounds 24 and 22 were active against Staphylococcus aureus and Bacillus subtilis at the concn. of 1 $\mu$g/ml respectively; 2) Compounds 9 and 29 were active against Trichophyton rubrum at the concn. of 2 $\mu$g/ml respectively; 3) Compouns 9 and 30 were active against Microsporum gypseum at the concn. of 2 $\mu$g/ml respectively; 4) Compounds 6,9,13,15,21,28,29,31,33 and 34 were active against Epidermophyton floccosum at the concn. of 1 $\mu$g/ml respectively; 5) Compounds 6,9,18 and 28 were active against Aspergillus niger and Aspergillus oryzae at the concn. of 1 $\mu$g/ml respectively.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.2
• /
• pp.230-234
• /
• 2019

Currently, the genetic modification of Aspergillus oryzae is mainly dependent on protoplast-mediated transformation (PMT). In this study, we established a dual selection marker system in an industrial A. oryzae 3.042 strain by using Agrobacterium tumefaciens-mediated transformation (ATMT). We first constructed a uridine/uracil auxotrophic A. oryzae 3.042 strain and a pyrithiamine (PT)-resistance binary vector. Then, we established the ATMT system by using uridine/uracil auxotrophy and PT-resistance genes as selection markers. Finally, a dual selection marker ATMT system was developed. This study demonstrates a useful dual selection marker transformation system for genetic manipulations of A. oryzae 3.042.

• Korean Journal of Food Science and Technology
• /
• v.47 no.1
• /
• pp.111-118
• /
• 2015

In the present study, the phenolic compound level, antioxidant activity, and inhibition of lipid accumulation in Aspergillus oryzae-fermented water extracts of the Platycodon grandiflorum (PG) root and the Curcuma longa (CL) root were determined. Total polyphenol and flavonoid contents were decreased after fermentation. However, the flavonoid content of the fermented PG (FPG) was increased by 2.9-fold that of the PG before fermentation. In addition, the antioxidant activities were significantly decreased following fermentation. The potential anti-obesity activity was assessed by determining lipid accumulation and mRNA expression of sterol regulatory element-binding protein 1c (SREBP-1c) and peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) in 3T3-L1 cells. Aspergillus-fermented extracts of PG and CL roots decreased lipid accumulation, and mRNA expression of SREBP-1c and $PPAR{\gamma}$ in 3T3-L1 cells. These results indicate that Aspergillus fermentation augments the anti-obesity activity of PG and CL by regulating the expression of the genes involved in lipid accumulation and cell differentiation of 3T3-L1 cells.

• Korean Journal of Food Science and Technology
• /
• v.32 no.2
• /
• pp.410-416
• /
• 2000

Changes in microflora and enzyme activities of three kinds of kochujang were investigated during 6 months of fermentation. Three different kinds of kochujang were prepared using Aspergillus oryzae, Aspergillus oryzae plus Bacillus licheniformis and Aspergillus oryzae, Bacillus licheniformis plus Saccharomyces rouxii. The pH of kochujang showed a slight decrease during fermentation. The number of mold and bacteria increased up to 30 days of fermentation and then decreased rapidly thereafter and the numbers of yeast increased after 30 days of fermentation. The viable cell counts of anaerobic bacteria increased remarkably up to 30 days of fermentation and then decreased to 60 days of fermentation. The activities of ${\alpha}-$, ${\beta}-\;amylase$ and protease were the highest in kochujang prepared with Aspergillus oryzae plus Bacillus licheniformis.

• Microbiology and Biotechnology Letters
• /
• v.31 no.2
• /
• pp.124-128
• /
• 2003

In order to isolate and characterize a novel fungal strain capable of producing cellulase, each samples of the old rice straw, soil, and the old tree were screened by congo red test. One of the fungi screened has been identified as Aspergillus tubingensis strain from the results of the phylogenic analysis based on partial DNA sequence and the basis of its biochemical properties. A carboxymethyl cellulase activity of the strain was higher than that of A. oryzae KCTC 6291. In CMCase activity measurement, it wasn't sensitive about pH 2.0, 3.0, 4.0, but the enzyme was more stable than A. oryzae under the various pH and temperature conditions and the enzyme activity was more similar to neutrality and alkali. Therefore, it could be suggested that the isolated strain has a potential possibility for the developing of the probiotics.