• Food Science and Preservation
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• v.24 no.8
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• pp.1168-1179
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• 2017

In this study, we tried to screen the Bacillus strain having safety probability by isolation of strains from traditional fermented food, measurement of probiotic properties, and the fermentative characteristics of Cheonggukjang. We isolated 400 Bacillus-like isolates from traditional fermented foods. Selected strains examined on the prevalent characteristic such as extracellular enzyme and antibacterial activities, and their safety probability was confirmed by biogenic amine productivity, hemolytic, and harmful substances and enzyme productivity. We selected the 5 strains by analysis of biogenic amine, antibacterial and B. cereus toxic associated gene. Five selected strains were examined on cell surface hydrophobicity, and bile and acid tolerance, and we selected the SRCM100730 as the final strain. SRCM100730 was confirmed B. amyloliquefaciens by 16S rRNA sequencing, and named the B. amyloloquefaciens SRCM100730 (KCCM11966P). Finally, we manufactured Cheonggukjang using SRCM100730 for confirmation of fermentation properties. Manufactured Cheonggukjang did not contain B. cereus, and showed that ${\gamma}$-PGA and extracellular enzyme activities were superior to commercial Chunggukjang. Amino nitrogen content was 544.02 mg% and 26 free amino acid were detected, and the bitterness-related amino acid content was lower than commercial Cheonggukjang. Especially, the amount of GABA was 3 fold higher than commercial Cheonggukjang. These results suggest that SRCM100730 have high availability in commercial probiotics market and fermented food industry.

• Journal of The Korean Society of Grassland and Forage Science
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• v.35 no.4
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• pp.321-326
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• 2015

This study was performed to analyze the resident microbial flora and the effects of probiotic inoculation on the fermentation characteristics of whole grain naked barley (Hordeum Vulgare L.) with the goal of evaluating the possibility of utilization as fermented feedstuff. Naked barley grains were harvested 35 days after heading, and the microbial flora was analyzed using MALDI-TOF mass spectrometer. After inoculation of commercial microbes to the naked barley grain (BT), the pH and number of bacteria, such as aerobic bacteria, lactic acid bacteria, yeast and E. coli, were measured and compared with the non-inoculated control (BC). A total of 122 colonies was isolated from the naked barley grain and the most popular bacteria species was Staphylococcus xylosus (n = 30, 24.59%). The pH value decreased more rapidly in BT than in BC, and was significantly lower after 7 days of fermentation at $4.33{\pm}0.02$ and $4.83{\pm}0.01$, respectively. The number of aerobic bacteria, lactic acid bacteria and yeast showed an increasing trend within the first 7 days of fermentation, however, their numbers decreased at 28 and 42 days of fermentation. The population of lactic acid bacteria in BT was higher than in BC, but there was no significant different at 7 days of fermentation, with respective levels of $9.24{\pm}0.20$ and $9.01{\pm}0.10logCFU/g$ (p>0.05). The initial number of E. coli was very high in the naked barley grain but subsequently decreased significantly. After 7 days of fermentation, E. coli was not detected in either BT or BC samples. From these results, it appears that the fermentation of naked barley grain proceeded adequately after 7 days, and that fermentation contributes to the safety of naked barley grain during storage.

• Food Science and Preservation
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• v.22 no.5
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• pp.727-734
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• 2015

In this study, three GRAS (generally recognized as safety) strain was isolated from Doenjang and Cheonggukjang and identified as a protease-producing microorganism, following the appearance of a clear zone around its colony when cultured on a medium containing skim milk. Based on an analysis of the nucleotide sequence of 16S ribosomal RNA, the strains wereas identified as Bacillus amyloliquefaciens and wereas therefore named Bacillus amyloliquefaciens CDD5, Bacillus amyloliquefaciens CPD4, and Bacillus amyloliquefaciens CGD3. Here, we analyzed the protease and ${\alpha}$-glucosidase inhibitory activities of the three B. amyloliquefaciens strains. Among the isolated strains, B. amyloliquefaciens CGD3 exhibited the highest protease activity (9.21 U/mL, 24 hr). The protease activities of B. amyloliquefaciens CDD5 and B. amyloliquefaciens CPD4 reached 1.14 U/mL and 8.02 U/mL, respectively, at 48 hr. The proteases from the three B. amyloliquefaciens strains showed the highest activities within a pH range of 8.0-9.0 at $50^{\circ}C$, and casein was found to be the preferred substrate on evaluating enzyme activity in the substrate specificity assay. The B. amyloliquefaciens strains exhibited maximal growth when the nutrient broth medium had an initial pH within the range of 5.0-10.0, 6-9% sodium chloride (NaCl), and 5% glucose. B. amyloliquefaciens CDD5 exhibited a low ${\alpha}$-glucosidase inhibition rate (5.32%), whereas B. amyloliquefaciens CPD4 and B. amyloliquefaciens CGD3 exhibited relatively higher inhibition rates of 96.89% and 97.55%, respectively.