• Journal of the Korean Society of Food Culture
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• v.26 no.6
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• pp.734-742
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• 2011

This study was conducted to investigate the physicochemical characteristics of Eungi, which is used as a breakfast or health food. We manufactured lotus root starch and Eungi by a traditional method and discovered that the viscosity of Eungi with 4-5% starch content was similar to fermented milk. When the physicochemical properties and sensory acceptability of a Eungi beverage combined with different amounts (0.5, 1.0, 1.5, and 2.0%) of lotus root starch were investigated, consumer acceptability was highest with Eungi combined with 0.5% starch and 6% sugar. When the physicochemical properties and sensory acceptability of Eungi beverage combined with different extract bases were investigated, the acceptability of taste and texture was highest with purple sweet potato extract and the acceptability of color was highest with omija extracts.

• Food Science and Preservation
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• v.17 no.3
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• pp.410-417
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• 2010

Several extracellular protease-producing bacteria were isolated from Chungkookjang, a traditional Korean food of fermented soybeans, on skim milk agar plates. Among these bacteria, strain D14 exhibited the highest production (15.2 U/mL) and specific activity (40.0 U/mg protein) of extracellular protease activity as assessed on growth in a protease induction medium composed of 1% (w/v) soluble starch, 1.5% (w/v) skim milk, 0.5% (w/v) yeast extract, and 2% (w/v) NaCl. The bacterium was identified as Bacillus subtilis based on morphological and physiological characteristics and 16S rDNA sequence. A BLAST search of 16S rDNA sequences revealed that the isolate was most closely related to Bacillus subtilis subsp. subtilis strain NCIB 3610. The 16S rDNA sequence homology was 99.9%. Our isolate produced the highest level of protease when grown in a protease induction medium containing 1% (w/v) sorbitol and 0.5% (w/v) yeast extract. Fructose and glucose reduced enzyme production to 12.7% and 35.9%, respectively, of the level seen when the strain was grown in medium containing soluble starch. Soytone also reduced enzyme production to 61.4% of the level noted when the strain was grown in medium containing yeast extract.

• Food Science of Animal Resources
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• v.23 no.3
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• pp.262-268
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• 2003

Kefir is a traditional fermented milk in Caucasusian area and is made mainly of milk fermented with lactic acid bacteria and yeasts. Six typical kefir grains were selected from ten kefir grains collected from different locals in Korea. Kefir grains were gelatinous in texture and had various shapes of villi, grapes, leaves, hulled millets, and towels. To investigate predominant microflora of kefir grains, SPC, MRS, M17, Rogosa, and APT agar media were used for viable cell count MRS, SPC, and Rogosa media were most acceptable for bacterial cell counts of the selected kefir grains. From one or two of the SPC agar plates which contained around 25∼50 colonies, all grown colonies were isolated and identified. Most predominant bacteria was identified as Lactobacillus fermentum by API 50 CHL kit. The proportions of Lb. fermentum and Lb. brevis among the total identified bacteria were around 41~88% and M4%, respectively. To select the best preservation method for kefir grains, refrigeration, freezing, and freeze drying were compared. Freeze drying was found most suitable for the preservation of kefir grains, based upon their acid-producing activities and production of off-flavors.

• Journal of Microbiology and Biotechnology
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• v.17 no.9
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• pp.1469-1476
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• 2007

Jeot-gal is a traditional Korean fermented seafood and has long been used for seasoning. We isolated 188 strains from shrimp, anchovy, and yellow corvina Jeot-gal, and screened sixteen strains that showed strong fibrinolytic activities on a fibrin plate. Among those strains, the strain that had the largest halo zone was chosen and identified as Bacillus licheniformis by using 16S rDNA sequencing and an API CHB kit. The fibrinolytic activity of Bacillus licheniformis was characterized and designated as bpKJ-31. The active component of bpKJ-31 was identified as a 37 kDa protein, designated bacillopeptidase F, by internal peptide mapping and N-terminal sequencing. The optimum activity of bpKJ-31 was shown at pH 9 and $40^{\circ}C$, with a chromogenic substrate for plasmin. It had high degrading activity for the $B{\beta}$-chain and $A{\alpha}$-chain of fibrin(ogen), and also acted on thrombin, but not skim milk and casein. The amidolytic activity of bpKJ-31 was inhibited by 1 mM phenylmethanesulfonyl fluoride, but 1 mM EDTA did not affect the enzyme activity, indicating that bpKJ-31 is an alkaline serine protease, like a plasmin. The bpKJ-31 showed approximately 14.3% higher fibrinolytic activity than the plasmin. These features of bpKJ-31 make it attractive as a health-promoting biomaterial.

• Food Science and Preservation
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• v.24 no.5
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• pp.707-713
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• 2017

The objective of this study was to select yogurt starter from Korean traditional fermented foods. The 2 strains (KM24, KM32) among 50 strains of isolated lactic acid bacteria selected as starter based on milk clotting ability, antimicrobial activity against various pathogens, tolerance in artificial gastric and bile juice and growth in 10 % skimmed milk. The strains were identified as Lacobacillus plantarum (KM32) and Pediococcus pentosacesus (KM24) by 16S rRNA gene sequencing. Viable cell number of yogurt fermented with mixed strains (KM24 and KM32) was 9.66 log CFU/mL after fermentation for 48 h and maintained $10^9CFU/mL$ during fermentation for 72 h at $37^{\circ}C$. The pH and titratable acidity of mixed cultured yogurt were 4.25% and 0.83% after fermentation for 48 h at $37^{\circ}C$, respectively. The physico-chemical characteristics of mixed cultured yogurt after fermentation for 48 h were $38.45{\mu}g/mL$ (polyphenol content), 48.57% (DPPH radical scavenging activity) and 465.40 cp (viscosity), respectively. The mixed cultured yogurt maintained $10^9CFU/mL$ of lactic acid bacteria during storage 10 days at $4^{\circ}C$. The viable cell number of yogurt prepared with mixed culture(KM32+KM24) maintained higher and than that of control (L. casei) during storage. These results indicated the potential use of selected strains (KM32+KM24) isolated from kimchi as a yogurt starter with strong acid tolerance and probiotics properties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.7
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• pp.1109-1114
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• 2013

Microbial community analysis was performed on Tarak, a traditional Korean fermented milk product, by 16S rDNA cloning and pyrosequencing to obtain basic data for the standardization and systematization of the Tarak manufacturing process. Microbial analysis of the prokaryotic community revealed a slight difference in microbial abundance between Bontarak (n) and Tarak (n+1), but Firmicute was dominant at the phylum level. At the genus level, the Lactobacillus and Leuconostoc genera constituted over 90% of the population in Bontarak, but Lactococcus was the dominant genus in Tarak. Bontarak and Tarak showed further differences at the species level. Leuconostoc citreum was the dominant species in Bontarak, constituting 40% of the population. In eukaryotic community analysis, all samples were composed of Ascomycota at the phylum level. At the genus level, Saccharomyces was dominant in Bontarak (85% of the population), while Issatchenkia was dominant in Tarak (95% of the population). At the species level, Saccharomyces cerevisiae was detected at a relative abundance in Bontarak (82%), and Pichia kudriavzevii was the dominant species in Tarak, with a relative abundance of 95%. Sensory evaluation indicated that Tarak had a better appearance and texture than Bontarak. As sweetness was not significantly different between the two samples just slightly higher in Tarak, this was likely due to a significant decrease in sourness in Tarak. These results suggest that the microbial community used affects the quality of Tarak produced. Thus, a stable microbial community must be maintained for the production of Tarak with consistent quality.

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.506-515
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• 1995

The cultural characteristics of 60 strains of psychrotrophic lactic acid bacteria which were isolated from kimchi, a Korean traditional fermented vegetable food, and identified as Leuconostoc mesenteroides subsp. mesenteroides, Leu. mesenteroides subsp. dextranicum, Leu. paramesenteroides, Leu. lactis, Lactobacillus bavaricus and Lac. homohiochii were tested. All strains grew at $5^{\circ}C,\;10^{\circ}C\;and\;37^{\circ}C$ in tomato glucose broth, but not at $45^{\circ}C$. The optimum growth temperature of Leu. mesenteroides and Lactobacillus sp. were $33{\sim}34^{\circ}C\;and\;34{\sim}36^{\circ}C$, respectively. All strains of Leu. mesenteroides and Lactobacillus sp. grew at 4.8 and 4.2 of initial pH, but not at 4.0. The final pH of Leu. mesenteroides and Lactobacillus sp. in glucose broth were $3.84{\sim}4.10\;and\;3.82{\sim}3.99$, respectively. None of the 60 strains clotted milk nor reduced litmus in litmus milk. All strains of Leu. mesenteroides and Lactobacillus sp. grew in tomato glucose broth containing 7% ethanol or 6.5% NaCl, but not in the broth containing 15% ethanol or 10% NaCl. All strains grew in tomato glucose broth containing 40% bile juice and survived in the artificial gastric juice of pH 3.5. Furthermore, all strains of Leu. mesenteroides survived in the artificial gastric juice of pH 3.0. Since many strains of lactic acid bacteria tested in this study showed differences in several physiological characteristics from those described in Bergey's Manual of Systematic Bacteriology, it was considered that further tests would be necessary to clarify their positions in taxonomic system.

• Journal of Life Science
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• v.19 no.10
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• pp.1424-1431
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• 2009

Shrimp Jeot-Gal is a popular traditional Korean fermented seafood and has been used for seasoning. We isolated a bacterium showing strong extra-cellular fibrinolysis and chitinase activity from shrimp Jeot-Gal and the strain was designated SC082. SC082 was identified as Bacillus licheniformis by 16S rRNA sequence homology search. B. licheniformis SC082 exhibited optimum temperature, pH, and salt concentration at $37^{\circ}C$, pH 7.0, and 6%, respectively. Substrate specificity of the culture supernatant from B. licheniformis SC082 was detected in fibrin, skim milk, and chitin plate. The fibrinolytic activity was highly maintained up to $50^{\circ}C$ at a pH of 7.0 for 3 hr and was stable up to pH 9.0 at $37^{\circ}C$ for 3 hr. The chitinase activity was remarkably induced by addition of 1.0% colloidal chitin and the pH and temperature optima of the enzyme were 5.0 and $45^{\circ}C$, respectively. In sodium dodecyl sulfate-polyacrylamide gel electrophoresis and zymogram analysis, this strain produced three fibrinolytic isozymes and two chitinase isozymes. The approximate molecular weights of the putative fibrinolytic enzymes were 23.0, 62.0, and 72.0 kDa and those of the chitinases were 62.0 and 55.0 kDa, respectively. The antioxidant activity of SC082 was also measured by using 2,2-diphenyl-l-picryl-hydrazyl (DPPH) free radical. The DPPH radical scavenging was slightly increased in a dose-dependent manner.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.6
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• pp.812-813
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• 1995

Lactococcal cells are nutritionally fastidious and thus, generally cultured either in milk or M17 medium (Terzaghi and Sandine, 1975). In this study, Lactococcus cremoris wild-type (KH) and its less­proteolytic mutant (KHA1) cells were grown on the M17 medium or with modified M17 medium by replicated parallel experiments. The modified M17 medium had the same composition as M17 medium, except that lactose was replaced by glucose. Analyses of culture-broth samples, in which the M17 and the modified M17 media were used, were conducted by high-performance liquid chromatography (HPLC). But, working with these media created noisy problems in analyses of samples. Therefore, a new semi-synthetic medium was developed on the basis of nutritional requirements (Morishita et al., 1981). The composition of the semi-synthetic medium determined on the basis of the nutritional requirements and the composition of milk, is presented in Table 1. The composition of M17 medium is also presented and compared in the table. L. cremoris KH and KHA1 cells were grown again on the new synthetic medium containing glucose or lactose. The broth samples were then drawn and analyzed by HPLC. Clearer separations of fermented products were achieved from the new medium than those with the M17 and the modified M17 media. In comparison with the M17 or the modified M17 media, growth on the new medium was good (Kim et al, 1993). Additional fermentations were also carried out at a controlled pH of 7.0, where enhanced growth of lactococcal cells was obtained. In the fermentations, samples were also analyzed for the concentrations of sugar and lactic acid. The results showed that the new synthetic medium was as good as or better than the M 17 and the modified M 17 media. This is because casein hydrolysate in the synthetic medium provided a ready supply of amino acids and peptides for L. cremoris KH and KHA1 cells. Lactic acid bacteria (LAB) including Lactococcal cells have been known to be an effective means of preserving foods, at the same time as giving particular tastes in fields of dairy products. LAB also have always occupied an important place in the technology of sea products, and marine LAB have known to be present in traditional fermented products (Ohhira et al, 1988). To apply the new synthetic medium to marine LAB, two different LAB were isolated from pickled anchovy and pollacks caviar and were grown on the new media in which various concentrations of NaCl $(3, 5, 7 and 10\%)$ added. They were also grown on the medium solution in natural seawater $(35\%o\;salinity)$ and on the solution of natural seawater itself, too. As seen in Fig. 1, Marine LAB were grown best on the synthetic medium solution in natural seawater and the higher concentrations of NaCl were added to the medium, the longer lag-phase of growth profile appeared. Marine LAB in natural seawater were not grown well. From these results, the synthetic medium seems good to cultivate cells which are essential to get salted fish aged. In this study, it showed that the new synthetic medium provided adequate nutrition for L. cremoris KH and KHA1 cells, which have been used as cheese starters (Stadhouders et al, 1988). Using this new medium, the acid production capability of starter cultures could be also measured quantitatively. Thus, this new medium was inferior to the M17 or the modified M17 medium in culturing the cheese starters and in measuring fermentation characteristics of the starter cells. Moreover, this new medium found to be good for selected and well-identified marine LAB which are used in rapid fermentations of low-salted fish.

• Journal of Life Science
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• v.28 no.11
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• pp.1347-1353
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• 2018

The fermentation of non-digestible soy meal can convert polysaccharides into many compounds that have a wide variety of biological functions. Bacillus strains are capable of hydrolyzing non-digestible saccharides, such as melibiose, raffinose, and stachyose, found in soy meal components. A highly active ${\alpha}$-galactosidase (${\alpha}$-d-galactoside galactohydrolase, EC 3.2.1.22) was isolated from a bacterium in a traditional Korean fermented medicinal herb preparation. The isolate, T2-16, was identified as Bacillus coagulans based on its 16S rRNA sequence and biochemical properties, and the strain was named Bacillus coagulans NRR-1207. When incubated in 10%(w/v) skim milk, Bacillus coagulans NRR1207 caused a decrease in the pH of the culture medium, as well as an increase in titratable acidity and viable cell counts. This strain also showed higher activities of ${\alpha}$-galactosidase, ${\beta}$-galactosidase, ${\alpha}$-glucosidase, naphthol-AS-BO-phosphohydrolase, and acid phosphatase when compared to other enzymes. It hydrolyzed oligomeric substrates, such as raffinose and stachyose, and liberated galactose, indicating that the Bacillus coagulans NRR1207 ${\alpha}$-galactosidase hydrolyzed the ${\alpha}$-1,6 glycoside linkage. These results suggest that the decreased stachyose and raffinose contents observed in fermented soy meal are due to this ${\alpha}$-galactosidase activity. Bacillus coagulans NRR1207 therefore has potential probiotic activity and could be utilized in feed manufacturing, as well as for hydrolyzing non-digestible soy meal components.