• Preventive Nutrition and Food Science
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• v.16 no.1
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• pp.37-44
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• 2011

The potential probiotic of a total of 15 Bacillus species isolated from Korean soybean paste (doenjang) was evaluated. Among those tested, the CSY191 and CSY388 strains were selected as probiotic bacteria due to their acid and bile tolerance, respectively. These strains were classified as Bacillus subtilis based on morphological, physiological, and chemotaxonomic features as well as on phylogenetic analysis based on their 16S rDNA sequences. These strains CSY191 and CSY388 showed a significant survival with rate range of 30.0 to 58.3% and of 31.0% to 58.1%, respectively, under artificial gastric acidic conditions at pH 3.0. These CSY191 and CSY388 strains appeared to have high antimicrobial activity against Salmonella Typhimurium, Bacillus cereus and Listeria monocytogenes. Also, methanol extractions (surfactin-like compounds) of strain CSY191 and strain CSY388 activated RAW264.7 microphages and induced the production of nitric oxide (NO) in a concentration-dependent manner, respectively. Therefore, strain CSY191 and strain CSY388 can be used as potential probiotics.

• Korean Journal of Microbiology
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• v.49 no.4
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• pp.391-397
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• 2013

Changes in ${\beta}$-glycosidase activity, total phenolic and isoflavone contents, and antioxidant activities during the fermentation of Korean black soybeans (Seoritae and Seomoktae) fermented food cheonggukjang by the potential probiotic Bacillus subtilis CSY191 were investigated. The levels of total phenolic and isoflavone-malonylglycoside and -aglycone contents increased, while 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity and ferric reducing/antioxidant power (FRAP) increased, but the isoflavone-glycoside contents decreased after cheonggukjang fermentation. The content of antioxidant compounds, including isoflavone-aglycones and -malonylglycosides, was increased by fermenting-processing, whereas the content of isoflavone-glycosides was decreased in the fermented soybeans. In particular, the Seoritae soybean fermented at 3 $7^{\circ}C$ for 48 h displayed the highest antioxidant activities, compared to those of the Seomoktae soybean and the fermented. The highest levels of daidzein, glycitein, and genistein were present at concentrations of 253.0 ${\mu}g/g$, 72.5 ${\mu}g/g$, and 114.1 ${\mu}g/g$ after 48 h of Seoritae soybean fermentation. From those results, we suggest that the high antioxidant activity of cheonggukjang of black soybeans might be related to the markedly higher levels of total phenolic and isoflavone-aglycone and -malonylglycoside contents achieved during fermentation.

• Korean Journal of Environmental Agriculture
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• v.35 no.1
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• pp.62-71
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• 2016

BACKGROUND: Soybeans are the rich sources of isoflavones. To date, the changes of isoflavone contents in various black soybeans cheonggukjang during fermentation by Bacillus subtilis CSY191 has not been investigated.METHODS AND RESULTS: This study investigated the changes of total phenolic and isoflavone contents and antioxidant effects during cheonggukjang fermentation made with four black soybean (BS) cultivars including Cheongja, Cheongja#3, Geomjeong#5, and Ilpumgeomjeong with a potential probiotic Bacillus subtilis CSY191. The total phenolic contents, isoflavone-malonylglycoside and -aglycone contents, and antioxidant activity were increased in cheonggukjang at 48 h fermentation, while the content of isoflavone-glycosides was decreased during cheonggukjang fermentation. In particular, the Cheongja#3 soybean fermented at 37℃ for 48 h displayed the highest antioxidant activities, compared to those of the other BS cultivars tested. Also, the highest levels of total phenolic, daidzein, glycitein, and genistein were present at concentrations of 17.28 mg/g, 283.7 g/g, 39.9 g/g, and 13.2 g/g at the end of Cheongja#3 soybean fermentation.CONCLUSION: The results from this study suggested that the enhanced antioxidant activity of cheonggukjang of BS might be related to increased levels of total phenolic, isoflavon-aglycone, and malonyl-glycoside contents achieved during fermentation. Furthermore, fermented Cheongja#3 soybean showed the highest levels of enhanced antioxidant activities than the other BS cultivars.