• The Korean Journal of Mycology
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• v.26 no.4 s.87
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• pp.478-486
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• 1998

The isolates of Rhizopus collected from Korean traditional fermented food meju and nuruk, were compared with the well known species of Rhizopus donated. The isolates of Rhizopus were identified with the numerical analyses calculated from RAPD-DNA bands, and confirmed with the microscopic observations of morphological features on PDA. The isolates of R. oryzae purchased were segregated through the results of RAPD or the morphological features. The species of R. nigricans, known as an illegitimate species, were different from those of R. stolonife and it is estimated that they are species of Rhizopus, again. According to microscopic observations and the result of RAPD, Some isolates of R. oryzae purchased belong to R. nigricans and are completely different from R. oryzae in their growth. The isolates of R. nigricans included with several isolates of R. oryzae identified for the different phenotypes and were heterogenous. The isolate of R. oligosporus were speculated to be different from morphological features of Rhizopus, but to be similar to the species of Absidia on the apophysis of sporangium. Its sporangiophore or mycelium was observed to be dark black, but the sporangia were not in those of R. oligosporus. The isolates collected from Korean traditional nuruk showed genetic diversity, and also considered to be different tastes in Korean rice wines.

• Food Science and Biotechnology
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• v.18 no.6
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• pp.1423-1429
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• 2009

Rhizopus oryzae KSD-815 was isolated from nuruk that has been used to make Korean traditional wines. This study was performed to investigate the effect of cultures of R. oryzae KSD-815 on cardiovascular disorders and cancer metastasis. Firstly, these cultures were sequentially fractionationed with n-hexane (TAHe), ethylacetate (TAE), n-butanol (TAB), and $H_2O$ (TAW). The TAE inhibited the activity of angiotensin-converting enzyme (ACE) and TAB suppressed platelet aggregation in vitro. TAE and TAB inhibited cell motility of human breast cancer cells. Furthermore, TAW interrupted the formation of neovasculature and tube-like structure, and down-regulated the expression of angiogenic factors, basic fibroblast growth factor (bFGF), tumor necrosis factor-$\alpha$ (TNF-$\alpha$), and hypoxia-inducible factor-$1{\alpha}$ (HIF-$1{\alpha}$) in breast cancer cells. These results indicated that cultures of R. oryzae KSD-815 display the inhibitory activities on hypertension, platelet aggregation, and metastasis, and suggest that these cultures might be further probed for the purposes as therapeutic agents or dietary supplements.

• Journal of the East Asian Society of Dietary Life
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• v.27 no.3
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• pp.348-363
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• 2017

We analyzed the mixed culture characteristics of isolated brewing fungi obtained from Korean traditional nuruk for their development as fermentation starters. In a previous study, we selected appropriate fungi strains based on their large fungi bodies and strong enzyme activities. These fungi strains were mixed cultured under various combination of ratios, pHs and temperatures. As a result, total acidities of R. delemar mixed culture media were higher than those of A. oryzae cultured at $20^{\circ}C$ and $37^{\circ}C$. The pHs of A. luchuensis 34-1 and A. oryzae 37-7 as well as R. delemar 58-8 and A. oryzae 37-7 mixed culture media gradually increased with the culture period. On the contrary, total acidities of the mixed culture media gradually decreased. ${\alpha}-Amylase$ activities of R. delemar 26-4 and R. oryzae 82-7 mixed culture media were strong at $20^{\circ}C$ and pH 4, glucoamylase activities of R. delemar 58-8 and A. oryzae 37-7 were strong at $37^{\circ}C$, pH 3 and 1:2 ratio, and acidic protease activities of R. delemar 26-4 and A. oryzae 78-5 were strong at $20^{\circ}C$, pH 4 and 1:4 ratio. This study provides the optimal mixed culture conditions for fermentation starters based on changes in pH and total acidity, favorable enzyme activities, and fungi varieties.

• Microbiology and Biotechnology Letters
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• v.48 no.4
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• pp.471-479
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• 2020

The aim of this study was to investigate the anti-oxidant and anti-inflammatory activities of the Rhododendron weyrichii flower extract fermented using Shindari, a traditional Jeju barley Nuruk-based fermentation. In this study, we examined the antioxidant potential of R. weyrichii flower extracts (RF) and R. weyrichii flower extracts fermented with Nuruk or Shindari (RFFN or RFFS, respectively) using various in vitro antioxidant assays including DPPH and ABTS radical scavenging assays, total phenol content and FRAP assays. We also evaluated the anti-inflammatory activity of the RF and RFFS on murine RAW 264.7 cells. The anti-inflammatory activity was evaluated by treating the RAW 264.7 cells with various concentrations (6.25, 12.5, 25, and 50 ㎍/ml) of RF or RFFS. As a result, we observed that the ABTS radical scavenging activity and total phenol content of RFFS was higher than that of RF and RFFN. Additionally, lipopolysaccharide-induced nitric oxide (NO) production was significantly lower in RFFS-treated cells when compared to the LPS-treated control. In addition, RFFS-treated cells exhibited decreased expression of inducible NO synthase (iNOS) proteins and high-performance liquid chromatography (HPLC) fingerprinting showed that both the quercetin and quercetin glucoside (quercitrin and isoquercitrin) levels were affected by the fermentation process. In conclusion, our data suggests that traditional fermentation could be an important strategy in improving the biological properties of raw materials including their antioxidant and anti-inflammatory activities. Finally, RFFS may be a candidate for developing topical antioxidant and anti-inflammatory agents.

• Journal of Microbiology and Biotechnology
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• v.32 no.7
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• pp.877-884
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• 2022

Probiotics are microorganisms that can benefit host health when ingested in a live state, and lactic acid bacteria are the most common type. Among fungi, Saccharomyces boulardii (SB) is the only strain known to have a probiotic function with beneficial effects on colitis; however, information on other probiotic yeast strains is limited. Therefore, this study aimed to discover yeast strains expressing intestinal anti-inflammatory activities by exhibiting probiotic properties in dextran sodium sulfate (DSS)-induced colitis mice model. Nuruk (Korean traditional fermentation starter) containing various microbial strains was used as a source for yeast strains, and S. cerevisiae 28-7 (SC28-7) strain was selected with in vitro and in vivo characteristics to enable survival in the intestines. After 14 days of pretreatment with the yeast strains, DSS was co-administered for six days to induce colitis in mice. The results revealed that the disease activity index score was lowered by SC28-7 treatment compared to the DSS group, and the colon length and weight/length ratio were recovered in a pattern similar to that of the normal group. SC28-7 administration significantly reduced the secretion of pro-inflammatory cytokines in the serum and modified the mRNA expression of inflammatory cytokines (interleukin-1β, transforming growth factor-β, and interferon-γ) and proteins involved in gut barrier functions (mucin 2, mucin 3, zonula occludens-1, and occludin) in colon tissues. These results indicate that SC28-7 attenuates DSS-induced colon damage and inflammation, supporting its future use as a probiotic yeast for treating and preventing intestinal inflammatory diseases such as inflammatory bowel disease.

• Microbiology and Biotechnology Letters
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• v.39 no.1
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• pp.56-62
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• 2011

We investigated quality characteristics of Seoktanju (one of the Korean traditional rice wine) which was fermented using five kinds of Korean commercial Nuruks. The purpose of this study was to research what effects on the quality of Seoktanju by using different Nuruks. We analyzed general component such as each mash's temperature change patterns, pH, titrable acidities, reducing sugar contents, volatile acids, and sugar contents during fermentation periods and studied sensory evaluation of produced Seoktanju (10 days). On the whole, temperature change patterns in the each mashes were depend on room temperature. All Seoktanju's pH was reduced rapidly up to three days after first mashing (pH 3.13-3.57) and after that was increased gradually. The end of fermentation pH was pH 3.6-4.05. Mostly, acidities were indicated high(0.59%) and Nuruk-B was showed highest acid value. These results seems to be different as occasion organic acids producing activity depend on the number of yeast, material contents, optimal temperature in the each mashes by fungi and lactic acid bacteria in Nuruks. In reducing sugar contents and sugar contents, Nuruk-C treatment were showed the highest value with 5.36%, $23^{\circ}brix$, respectively and alcohol content was lowest with 8.6%. In the five kinds of reproduced Seoktanju, alcohol content was the highest in the treated Nuruk-A group. Volatile acid value was the highest with 132.6~263.7 ppm at the 3 day after first mashing day but as the fermentation time goes on, it was reduced sharply by 5.25~5.94 ppm. Sensory evaluation was performed with 5 point scale, the Seoktanju using Nuruk-D was presented by 4 point, while Nuruk-A was presented lowest by 2.77 point on overall acceptability.

• Mycobiology
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• v.42 no.4
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• pp.361-367
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• 2014

Makgeolli, also known as Takju, is a non-filtered traditional Korean alcoholic beverage that contains various floating matter, including yeast cells, which contributes to its high physiological functionality. In the present study, we assessed the levels of ${\beta}$-glucan and glutathione in various yeast strains isolated from traditional Korean Nuruk and selected a ${\beta}$-glucan- and glutathione-rich yeast strain to add value to Makgeolli by enhancing its physiological functionality through increased levels of these compounds. Yeast ${\beta}$-glucan levels ranged from 6.26% to 32.69% (dry basis) and were strongly species-dependent. Dried Saccharomyces cerevisiae isolated from Nuruk contained $25.53{\mu}g/mg$ glutathione, $0.70{\mu}g/mg$ oxidized glutathione, and $11.69{\mu}g/g$ and $47.85{\mu}g/g$ spermidine and L-ornithine monohydrochloride, respectively. To produce functional Makgeolli, a ${\beta}$-glucan- and glutathione-rich yeast strain was selected in a screening analysis. Makgeolli fermented with the selected yeast strain contained higher ${\beta}$-glucan and glutathione levels than commercial Makgeolli. Using the selected yeast strain to produce Makgeolli with high ${\beta}$-glucan and glutathione content may enable the production of functional Makgeolli.

• Mycobiology
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• v.45 no.2
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• pp.119-122
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• 2017

Herein, nuruks derived from non-glutinous and glutinous rice inoculated with Aspergillus oryzae N159-1 (having high alpha-amylase and beta-glucosidase activities) were used to produce Korean alcoholic beverages. The resultant beverages had enhanced fruity (ethyl caproate and isoamyl alcohol) and rose (2-phenethyl acetate and phenethyl alcohol) flavors and high taste scores.

• Korean Journal of Food Science and Technology
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• v.54 no.3
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• pp.343-350
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• 2022

In this article, we report a case study on the cause of abnormal fermentation of Takju based on a microbial community analysis of wheat-based Nuruk and Takju using next-generation sequencing. The microbial community showed notable changes during alcoholic fermentation. Members of the genera Aspergillus and Staphylococcus were dominant in Nuruk, whereas Saccharomyces, Pediococcus, Bacillus, Lactobacillus, and Enterobacter were predominant during Takju fermentation. In particular, members of the Enterobacter and Bacillus genera that were present were identified as the opportunistic pathogens B. wiedmannii and E. cloacae. The relative abundance of two species increased in Mitsul-3, wherein the concentration of organic acid rapidly decreased, and in Deotsul-1, in which raw materials were added. Furthermore, the relative abundance of lactic acid bacteria (LAB) in both the Nuruk and Takju was very low. Therefore, this result showed that the abnormal proliferation of E. cloacae and B. wiedmannii in Takju was due to the absence of LAB.

• Korean Journal of Food Science and Technology
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• v.42 no.3
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• pp.298-303
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• 2010

This study was carried out to compare the physicochemical characteristics of Korean traditional wine fermented from foxtail millet and nuruk at different mixing rates. The alcohol contents of fermented wine ranged from 12.70 to 13.38%. Two kinds of commercial nuruks, SH and BS nuruk, were used. The brix degrees of foxtail millet wine fermented by SH and BS nuruks were 21.6 and $22.4^{\circ}Bx$, respectively. The pH, total acidity, and turbidity of the wines fermented by SH and BS nuruks were 3.74 and 3.40, 1.40 and 1.51%, and 0.441 and 0.149, respectively. With an increase in the amount of foxtail millet, brix degree, pH, turbidity, b-value and L-value decreased, and total acidity and a-value increased. Total color difference (${\Delta}Eab$) parameter of the wine fermented by SH nuruk were 8.58, 22.59 and 22.55, while those by BS nuruk were 0.35, 4.08 and 7.16 in 30, 70 and 100% addition rates of foxtail millet, respectively. With an increase in the amount added of foxtail millet, glucose content decreased. The organic acids such as lactic acid and acetic acid were predominantly detected in the fermented wine. Finally, based on sensory evaluations, the wine fermented by BS nuruk showed the best overall quality at the 30% addition rate of foxtail millet.