• Mycobiology
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• v.51 no.3
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• pp.139-147
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• 2023

Aspergillus sojae has long been considered a domesticated strain of Aspergillus parasiticus. This study delineated relationships among the two species and an Aspergillus PWE36 isolate. Of 25 examined clustered aflatoxin genes of PWE36, 20 gene sequences were identical to those of A. sojae, but all had variations to those of A. parasiticus. Additionally, PWE36 developmental genes of conidiation and sclerotial formation, overall, shared higher degrees of nucleotide sequence identity with A. sojae genes than with A. parasiticus genes. Examination of defective cyclopiazonic acid gene clusters revealed that the PWE36 deletion pattern was identical only to those of A. sojae. Using A. sojae SMF134 genome sequence as a reference, visualization of locally collinear blocks indicated that PWE36 shared higher genome sequence homologies with A. sojae than with A. parasiticus. Phylogenetic inference based on genome-wide single nucleotide polymorphisms (SNPs) and total SNP counts showed that A. sojae strains formed a monophyletic clade and were clonal. Two (Argentinian and Ugandan) A. parasiticus isolates but not including an Ethiopian isolate formed a monophyletic clade, which showed that A. parasiticus population is genetically diverse and distant to A. sojae. PWE36 and A. sojae shared a most recent common ancestor (MRCA). The estimated divergence time for PWE36 and A. sojae was about 0.4 mya. Unlike Aspergillus oryzae, another koji mold that includes genetically diverse populations, the findings that current A. sojae strains formed a monophyletic group and shared the MRCA with PWE36 allow A. sojae to be continuously treated as a species for food safety reasons.

• Journal of Microbiology and Biotechnology
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• v.2 no.3
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• pp.215-219
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• 1992

Biodegradation of azo dyes such as Amaranth, Sudan III and Congo-Red by Aspergillus sojae B-10 was demonstrated using Aspergillus sojae B-10. Aspergillus sojae B-10 showed the greatest decolorization ability when it was cultivated in a nitrogen-limited medium containing, azo dyes(10 mg/l), 2.0% glucose, 0.06% sodium nitrate, 0.1% $KH_PO_4$, 0.5% MgSO_4$ㆍ$7H_2O$ at pH 5.0 and $37^\circ{C}$ for 5 days. Under optimal conditions, Amaranth started being decolorized within 24 hr and was almost complete after decolorization of 4 days incubation. Sudan III was completely decolorized after a cultivation of 5 days. However, Congo-Red was not completely decolorized until 5 days of cultivation.

• Journal of Environmental Health Sciences
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• v.21 no.4
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• pp.10-16
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• 1995

Dyes are released into the environment from industrial wasterwater. They are considered to be a pollution problem because of the wide spread into environment with a variety of colors. In order to biological treatment of industrial dyes waste water, biodegradation of reactive dyes such as Rifacion Red H-3EB, Rifazol Blue BT, Rifacion Yellow P-4G and Rifacion Brown RT were carried out decolorized by Aspergillus sojae B-10. Aspergillus sojae B-10 showed the almost completely biodegradation ability when it was cultivated in a 2.0% glucose, 0.06% sodium nitrite, 0.1% $KH_2PO_4$, 0.5% $MgSO_4\cdot 7H_2O$ containing each reactive dyes (500 ppm) under the optimal conditions of 32$\circ$C and pH 5. The mycelium of Aspergillus sojae B-10 was produced extracellular enzyme which has concerned responsible for dyes biodegradation. Under optimal conditions, reactive dyes started being decolorized within 24 hr and its was almost decolorized c ompletely after 5 days incubation. Rifazol blue RT was not completely decolorized until 5 days of cultivation. Rafacion Red BT, Rifasol blue BT and Rifacion yellow P-4G were completely decolorized after 5 days cultivation.

• Journal of Environmental Health Sciences
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• v.21 no.4
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• pp.49-55
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• 1995

Dyes are released into the environment as industrial wasterwater. Dyes are considered to be a pollution problem because of the wide spread into environment with a variety of colors. Continuous biodegradation of reactive dyes such as Rifacion Red H-3EB, Rifazol Blue BT, Rifacion Yellow P4G and Rifacion Brown RT were demonstrated using multistage rotating disc contactor immobilized by Aspergillus sojae B-10. Aspergillus sojae B-10 was cultivated the optimal medium containing 2.0% glucose, 0.08% $NaNO_3$, 0.1% $KH_2PO_4$ and 0.5% $MgSO_4\cdot 7H_2O$, pH 5 at 32$\circ$C. Mycelium of Aspergillus sojae B-10 were guck to the rotating disc for 10 days until steady state. For continuous biodegradation of reactive dyes by using rotating disc contactor, it was most effective biodegradation in the medium containing 1,000 ppm each dyes at the medium feeding rate of 20 ml per hour. Under the conditions biodegradation of each dyes on 2, 4 and 6 days were 20~50%, 75% and 96%, respectively. Therefore, practical application of reactive dyes were carried out at the feeding rate of 20 ml/h as synthetic wasterwater containing 500 ppm of mixture reactive dyes. It was found the highest levels of 94% biodegradation during 20 days.

• Proceedings of the Korean Society of Life Science Conference
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• 2003.10a
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• pp.159-159
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• 2003

• 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.7
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• pp.67-77
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• 1966

For the production of proteolytic enzyme wilth Aspergillus, the examination is made on the culture-time and koji extracting conditions, during producing koji. 1. The highest activity showed up when the culture-time took 50 hours for Aspergillus sojae and 60 hours for Aspergillus flavus. 2. When the cultured koji was extracted by a buffer solution and water, the former gave the product of higher activity until pH 7 through pH 12, and water until pH 3 through pH 7. 3. In the method of crushing and granule extractions, crushing extraction produced the one of higher activity than granule. 4. The highest activity showed up when Aspergillus sojae took 5 hours (Aspergillus flavus 4 hours) in the time of extracting enzyme solution. 5. The highest activity showed up when both Aspergillu sojae and Aspergillus flavus reacted and indicated $37.60^{\circ}C$ in the reaction temperature and activity.

• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.4
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• pp.309-312
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• 2004

Aspergillus sojae B-l0 was immobilized and used to treat model dye compounds. The model wastewater, containing 10 ppm of azo dyes such as Amaranth, Sudan III, and Congo Red, was treated with cells attached to a rotating disc contactor (RDC). Amaranth was decolorized more easily than were Sudan III and Congo Red. Decolorization of Amaranth began within a day, and the dye was completely decolorized within 5 days of incubation. Both Sudan III and Congo Red were almost completely decolorized after 5 days of incubation. Semicontinuous decolorization of azo by reusing attached mycelia resulted in almost complete decolorization in 20 days. This experiment indicated that decolorization was successfully conducted by removing azo dyes with Aspergillus sojae B-10.

• Food Science and Biotechnology
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• v.17 no.3
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• pp.527-533
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• 2008

For preparation of high quality kochujang by the traditional fermentation method, 4 types of kochujang were prepared with brick- or grain-shaped meju fermented with different strains (Aspergillus sojae, Aspergillus oryzae+Bacillus subtilis). After 100 days of fermentation at $25^{\circ}C$, the moisture, pH, salt, and ethanol content of kochujang were 40.52-43.20%, 4.71-4.82, 8.7-9.1%, and 0.75-0.94%, respectively, showing slight differences according to the strains and shapes of meju. Titratable acidities were slightly increased for up to 60 days of fermentation. The amino-type nitrogen content of kochujang prepared with brick-shaped meju (A. oryzae+B. subtilis) was the highest (164.20 mg%) among all of the kochujang types. The redness (a) value of kochujang prepared with brick-shaped meju (A. sojae) were higher (19.08) than those of other treatments (18.37-18.59). Sensory evaluation of kochujang prepared with grain-shaped meju (A. sojae) showed the highest scores for color and overall acceptability, 'at $6.43{\pm}1.87$ and $6.29{\pm}1.44$, respectively. It was estimated that high quality kochujang could be made by using meju fermented with selected strains.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.251-261
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• 2017

Initially, we screened 18 Aspergillus sojae-like strains from Aspergillus spp. isolated from meju (Korean traditional fermented soybean brick) according to their morphological characteristics. Because members of Aspergillus section Flavi are often incorrectly identified because of their phylogenetic similarity, we re-identified these strains at the morphological and molecular genetic levels. Fourteen strains were finally identified as A. sojae. The isolates produced protease and ${\alpha}-amylase$ with ranges of 2.66-10.64 and 21.53-106.73 unit/g-initial dry substrate (U/g-IDS), respectively, which were equivalent to those of the koji (starter mold) strains employed to produce Japanese soy sauce. Among the isolates and Japanese koji strains, strains SMF 127 and SMF 131 had the highest leucine aminopeptidase (LAP) activities at 6.00 and 6.06 U/g-IDS, respectively. LAP plays an important role in flavor development because of the production of low-molecular-weight peptides that affect the taste and decrease bitterness. SMF 127 and SMF 131 appeared to be non-aflatoxigenic because of a termination point mutation in aflR and the lack of the polyketide synthase gene found in other A. sojae strains. In addition, SMF 127 and SMF 131 were not cyclopiazonic acid (CPA) producers because of the deletion of maoA, dmaT, and pks/nrps, which are involved in CPA biosynthesis. Therefore, A. sojae strains such as SMF 127 and SMF 131, which have high protease and LAP activities and are free of safety issues, can be considered good starters for soybean fermentations, such as in the production of the Korean fermented soybean products meju, doenjang, and ganjang.