• Journal of Microbiology and Biotechnology
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• 제28권12호
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• pp.1971-1981
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• 2018

In this study, we investigated the altered enzymatic activities and metabolite profiles of koji fermented using varying permutations of Aspergillus oryzae and/or Bacillus amyloliquefaciens. Notably, the protease and ${\beta}$-glucosidase activities were manifold increased in co-inoculated (CO) koji samples (co-inoculation of A. oryzae and B. amyloliquefaciens). Furthermore, gas chromatography-mass spectrometry (GC-MS)-based metabolite profiling indicates that levels of amino acids, organic acids, sugars, sugar alcohols, fatty acids, nucleosides, and vitamins were distinctly higher in CO, SA (sequential inoculation of A. oryzae, followed by B. amyloliquefaciens), and SB (sequential inoculation of B. amyloliquefaciens, followed by A. oryzae). The multivariate principal component analysis (PCA) plot based on GC-MS datasets indicated a clustered pattern for MA and MB (koji samples inoculated either with A. oryzae or B. amyloliquefaciens) across PC2 (20.0%). In contrast, the CO, SA, and SB metabolite profiles displayed segregated patterns across PLS1 (22.2%) and PLS2 (21.1%) in the partial least-square discriminant analysis (PLS-DA) model. Intriguingly, the observed disparity in the levels of primary metabolites was engendered largely by higher relative levels of sugars and sugar alcohols in MA, SA, and CO koji samples, which was commensurate with the relative amylase activities in respective samples. Collectively, the present study emphasizes the utility of integrated biochemical and metabolomic approaches for achieving the optimal permutation of fermentative inocula for industrial koji preparation.

• Journal of Microbiology
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• 제43권6호
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• pp.475-486
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• 2005

Fungal secondary metabolites constitute a wide variety of compounds which either playa vital role in agricultural, pharmaceutical and industrial contexts, or have devastating effects on agriculture, animal and human affairs by virtue of their toxigenicity. Owing to their beneficial and deleterious characteristics, these complex compounds and the genes responsible for their synthesis have been the subjects of extensive investigation by microbiologists and pharmacologists. A majority of the fungal secondary metabolic genes are classified as type I polyketide synthases (PKS) which are often clustered with other secondary metabolism related genes. In this review we discuss on the significance of our recent discovery of chalcone synthase (CHS) genes belonging to the type III PKS superfamily in an industrially important fungus, Aspergillus oryzae. CHS genes are known to playa vital role in the biosynthesis of flavonoids in plants. A comparative genome analyses revealed the unique character of A. oryzae with four CHS-like genes (csyA, csyB, csyC and csyD) amongst other Aspergilli (Aspergillus nidulans and Aspergillus fumigatus) which contained none of the CHS-like genes. Some other fungi such as Neurospora crassa, Fusarium graminearum, Magnaporthe grisea, Podospora anserina and Phanerochaete chrysosporium also contained putative type III PKSs, with a phylogenic distinction from bacteria and plants. The enzymatically active nature of these newly discovered homologues is expected owing to the conservation in the catalytic residues across the different species of plants and fungi, and also by the fact that a majority of these genes (csyA, csyB and csyD) were expressed in A. oryzae. While this finding brings filamentous fungi closer to plants and bacteria which until recently were the only ones considered to possess the type III PKSs, the presence of putative genes encoding other principal enzymes involved in the phenylpropanoid and flavonoid biosynthesis (viz., phenylalanine ammonia-lyase, cinnamic acid hydroxylase and p-coumarate CoA ligase) in the A. oryzae genome undoubtedly prove the extent of its metabolic diversity. Since many of these genes have not been identified earlier, knowledge on their corresponding products or activities remain undeciphered. In future, it is anticipated that these enzymes may be reasonable targets for metabolic engineering in fungi to produce agriculturally and nutritionally important metabolites.

• Fisheries and Aquatic Sciences
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• 제13권1호
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• pp.12-17
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• 2010

This study was conducted to evaluate the potential of a microbial fermentation procedure to improve the functional qualities of seaweeds. Aspergillus oryzae, which has been used in traditional Korean fermented foods, was inoculated and cultivated in an aqueous extract of sea tangle (Laminaria japonica). Fermentation of the sea tangle extract by A. oryzae for 4 days resulted in a 3-fold increase in $\gamma$-aminobutyric acid (GABA) content. GABA is known to be a bioactive compound. Fungal fermentation of the extract also enhanced its antioxidant activity and increased its total content of phenolic compounds. It was assumed that these changes stemmed from the biodegradation of active compounds of the sea tangle packaged within its rigid structural matrix or occurred as result of fungal fermentation. These results suggested that the application of microbial fermentation to the processing of seaweeds will help in the development of processed foods to meet consumer demands.

• 대한본초학회지
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• 제26권4호
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• pp.109-113
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• 2011

Objectives : We investigated the antioxidant and Antidiabetic effects of Cnidii Rhizoma Fermentata by Aspergillus oryzae and Aspergillus Kawauchi for 3days. Methods : In this study we compared Cnidii Rhizoma Fermentata with Aspergillus oryzae and Aspergillus Kawauchi that examined using reducing sugar, DPPH radical scavenging activity, ${\alpha}$-amylase and ${\alpha}$-glucosidase inhibitory activity. Also determined changes of pH and sugar content during fermentation for 3days. Results : The values for DPPH radical scavenging activity of Cnidii Rhizoma fermented by Aspergillus oryzae (86.6%) was higher than that of Aspergillus Kawauchi (77.9%). In ${\alpha}$-amylase inhibitory activity, fermented by Aspergillus Kawauchi had the highest inhibitory activity among other groups. But in ${\alpha}$-glucosidase inhibitory activity, fermented by Aspergillus oryzae had the highest inhibitory activity among other groups. While all groups of the sugar content increased During 3days fermentation, the pH was decreased. Conclusions : Based on these results, It was suggested that Cnidii Rhizoma Fermentata can be a useful and cost-effective resource for fuctional food and medicine.

• Journal of Applied Biological Chemistry
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• 제63권3호
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• pp.229-234
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• 2020

Beer production with rice or other malt substitutes suffers from a lack of suitable enzymes for saccharification. For this reason, rice nuruk (fermentation starter) was tested as a starch replacement for malt in the saccharification process of beer production. The results of this study show that the enzyme activities of rice nuruk made with brewing fungi were higher than those of malt. Saccharification and glucoamylase activities were high in Aspergillus awamori KCCM 30790 and α-amylase activity was high in Aspergillus oryzae CF1003. Overall, malt beer had significantly higher alcohol, pH, total acid, volatile acids, amino acids, free amino nitrogen, bitterness unit and ΔE than rice nuruk beer. Where as Aspergillus awamori KCCM 30790 beer had significantly higher soluble solids, reducing sugar than malt beer. According to a sensory evaluation, malt beer was better color, flavor and Aspergillus oryzae CF1003 beer was better taste, texture, overall acceptability than other beer. Therefore Aspergillus awamori KCCM 30790 beer was suitable considering enzyme activities (saccharification, glucoalmylase) and physicochemical characteristics (soluble solids, reducing sugar). And then Aspergillus oryzae CF1003 beer was suitable considering sensory evaluation (taste, texture, overall acceptability). Therefore rice nuruk like Aspergillus awamori KCCM 30790 and Aspergillus oryzae CF1003 were suitable as a substitute material that can replace for malt in beer proceccing.

• 한국미생물·생명공학회지
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• 제10권3호
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• pp.227-232
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• 1982

삶은 콩을 이용한 고체 배지상에서 Aspergillus oryzae의 성장 속도를 측정하는 방법에 대하여 연구하고 이들 방법을 대두와 루우핀콩 배지에서의 균 성장 특성을 비교하는데 적용하였다. 여러가지 배지 조건에서 배양 기간에 따른 균체 colony의 형성시간 크기변화, $\alpha$-아미노 질소함량의 변화, 포자형성 시간 및 균사길이의 변화등을 측정 비교하였다. 배지의 종류에 따라 Aspergillus oryzae는 특정한 균체 colony 형성시간을 나타내었으며 colony 형성후 부터는 colony 직경의 크기는 배양시간에 따라 직선적으로 증가하였다. 균체colony 직경은 배지중의 $\alpha$-아미노 질소함량과 높은 직접적인 상관관계를 나타내었으나 배지의 수분함량이 변하면 이러한 상관관계가 성립되지 않았다. 오히려 배지의 수분함량이 증가하면(60%-85%) $\alpha$-아미노 질소함량은 증가하나 colony 직경은 감소하는 역 관계를 나타내었다. 일반적으로 Aspergillus oryzae는 삶은 루우핀콩 페이스트에서 최초 성장 속도가 대두보다 발랐으며. 루우핀콩 배지에서의 colony 형성시간이 24시간인데 반해 대두에서는 44.4 시간이 걸렸다. 그러나 colony 형성이후의 성장 속도는 대두에서 더 빠르게 나타나 대두의 경우 8.83mm/day 인데 반하여 루우핀 콩에서는 7.05mm/day이었다. spore 형성 시간은 colony 형성 시간과 깊은 상관관계를 나타내었으며 일반적으로 루우핀콩에서 spore 형성 시간이 짧았다. 콩의 표면에서 균사길이를 측정하는 방법은 간단하고 빨리 균체의 성장 속도를 비교할수 있 었으며 특히 콩의 구조와 형태가 균체 성장에 미치는 영향을 조사하는데 편리하였다. 본 실 험에서는 이 방법으로 루우핀콩의 두꺼운 외피가 균체 성장을 저해하고 있음을 발견하였다.

• 한국식품영양학회지
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• 제6권2호
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• pp.89-95
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• 1993

A Nuluk, a Korean traditional Koji for brewing, was made with wheat flour and Aspergillus oryzae L2 which had a good aroma and strong abilities In producing saccharogenic and dextrogenic enzymes. The cultural conditions for the production of saccharogenic and proteolytic enzymes were tested. The productivity of dextrogenic enzyme was improved when Nuluk was made with unsteamed wheat flour as compared with steamed one, but that of proteolytic enzyme was reduced. The addition of water containing 0.5% hydrochloric acid was unfavorable for the production of those two enzymes. The optimum ratio of water added to wheat flour for the production of those two enzymes was 28$^{\circ}C$ on the basis of wheat flour, The productivity of saccharogenic enzyme was enhanced when the Nuluk was molded after 20 hours of precultivation, but that of proteolytic enzyme was reduced as compared with no molding. The optimum temperatures for the production of saccharogenic enzyme and proteolytic enzyme were 36$^{\circ}C$ and 28$^{\circ}C$, respectively.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권4호
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• pp.253-262
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• 2000

Aspergillus is considered to be an attractive host for heterologous protein production because of its safety and ability to secrete large amounts of proteins. In order to obtain high productivity, thus far promoters of amylases have been most widely used in A. oryzae. Recent progress in cloning and expression analysis, including EST sequencing, revealed that glycolytic genes represent some of those most strongly expressed in A. oryzae. Therefore, promoters of glycolytic genes could be important alternatives to promoters of amylases because lower amounts of proteases are produced in the presence of glucose. Several A. oryzae transcription factors responsible for the induction and/or maximum expression of many industrially important genes encoding amylases and proteases have been cloned and characterized. In addition to the transcriptional regulatory factors, the gene encoding the largest subunit of RNa polymerase II, constituting the basic transcription machinery, has also been cloned from A. oryzae. This recently acquired understanding of the details of transcriptional regulatory mechanisms and factors will facilitate engineering flexible controls for the expression of proteins important for the fermentation industries.

• 한국균학회지
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• 제40권4호
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• pp.187-190
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• 2012

다양한 향미를 가진 막걸리의 개발을 위해 전통누룩으로부터 분리한 곰팡이로 입국을 제조한 후 품질특성을 분석하여 입국의 규격에 적합하며 이취가 없고 관능이 우수한 9균주를 입국 제조용 우수균주로 최종 선발하였다. 선발된 균주는 Aspergillus oryzae(C1-5-2-2, C20-7-3, CN1.3.1-4, CN16.19.1-1, N152-1, N220-1), Mycocladus corymbiferus(N162-2), Rhizopus oryzae(N20), Lichtheimia corymbifera(N21)로 동정되었으며, 제조한 입국의 산도는 5.0~6.8, 당화력은 128~241sp이었다.

• 한국식품영양과학회지
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• 제29권6호
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• pp.987-994
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• 2000

한국 전통누룩으로부터 분리.동정된 Asp. coreanus NR 15-1, Asp. oryzae NR 15-3, 그리고 Asp. oryzae NR 2-5로부터 amylase활성이 높고 세포융합에 사용될 변이주를 분리하고 그의 특성을 검토했다. Aspergillus 속 사상균을 변이처리하기 위한 변이원으로는 NTG를 사용하였으며 Asp. coreanus NR 15-1로부터 총 15종의 변이주중 8종의 영양요구변이주, Asp. oryzae NR 15-3 으로부터 총 5종중 3종의 영양요구변이주를, Asp. oryzae NR 2-5로부터 총 6종중 2종의 영양요구변이주를 분리하였다. 이들 영양요구변이주는 최소배지 에서는 생육하지 않았으며 특정 아미노산과 핵산염기 등을 배지에 첨가했을 경우에만 생육하였다. 분리된 변이주의 당화력, 액화력 및 산 생성능 등을 검토한 결과, 산 생성능이 우수한 균주인 Asp. coreanus NR 15-1로부터 glucoamylase 활성이 높은 \ulcorner(Arg.￣) 변이주와 Asp. oryzae NR 2-5로 부터 $\alpha$-amylase 활성이 우수한 영양요구변이주인 Z6(Ade.￣) 변이주를 세포융합에 사용이 가능한 변이주라 사료되었다. 앞으로 이 들의 변이주를 대상으로 세포융합을 통해 우수한 사상균주를 획득할 수 있는 기초적 자료가 됨으로서 전통누룩의 과학화에 기여할 뿔만 아니라 외국 주류와 경쟁력이 있고 과학화된 전통주류의 개발이 가능하리 라 사료된다.