• Korean Journal of Microbiology
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• v.54 no.4
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• pp.453-455
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• 2018

Bacillus licheniformis strain 0DA23-1, a potential fermentation starter candidate, was isolated from doenjang, a Korean high-salt-fermented soybean food. Strain 0DA23-1 contains a single circular 4,405,373-bp chromosome with a G + C content of 45.96%. The complete genome of strain 0DA23-1 does not include any of the virulence factors found in the well-known pathogens Bacillus cereus and Staphylococcus aureus. Additionally, no genes associated with resistance to eight antibiotics (chloramphenicol, clindamycin, erythromycin, gentamicin, kanamycin, streptomycin, tetracycline, and vancomycin), hemolysis, or biofilm formation were identified.

• Journal of Dairy Science and Biotechnology
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• v.41 no.3
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• pp.138-148
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• 2023

In this study, Lactococcus lactis subsp. hordniae JNU533 (JNU533) was isolated from Swiss-type cheese, and the bacteriocin produced by this strain was characterized. The spot-on-lawn assay was used to determine the antimicrobial spectrum and characteristics of the JNU533-derived bacteriocin. Results confirmed that the JNU533-derived bacteriocin inhibited the growth of lactic acid bacteria. The size of the bacteriocin was approximately 4.9 kDa, and it was heat- and pH-stable under various temperature and pH conditions. Furthermore, the possibility of using JNU533 as a starter culture in the manufacturing of fermented dairy products was assessed. A single colony of JNU533 was inoculated into 10% skim milk containing 0.5% glucose to investigate its characteristics in milk culture. The decrease in the pH was similar to that elicited by Lactobacillus delbrueckii subsp. bulgaricus. Furthermore, the results confirmed that JNU533 inhibited the growth of various bacteria and could be used as a milk fermentation starter. This study highlights the characteristics of the bacteriocin produced by JNU533 and the growth features of this strain in a skim milk medium.

• Food Science of Animal Resources
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• v.39 no.1
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• pp.162-176
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• 2019

This study was performed to evaluate the antioxidant activity of yogurt fermented at low temperature and the anti-inflammatory effect it has on induced colitis with 2.5% dextran sodium sulfate (DSS) in Balb/c mice. Yogurt premix were fermented with a commercial starter culture containing Lactobacillus acidophilus, Bifidobacterium lactis, Streptococcus thermophilus, and Lactobacillus delbrueckii subsp. bulgaricus at different temperatures: $22^{\circ}C$ (low fermentation temperature) for 27 h and $37^{\circ}C$ (general fermentation temperature) for 12 h. To measure antioxidant activity of yogurt samples, DPPH, $ABTS^+$ and ferric reducing antioxidant potential (FRAP) assays were conducted. For animal experiments, inflammation was induced with 2.5% DSS in Balb/c mice. Yogurt fermented at low temperature showed higher antioxidant activity than that of the yogurt fermented at general temperature. In the inflammatory study, IL-6 (interleukin 6) was decreased and IL-4 and IL-10 increased significantly in DSS group with yogurt fermented at general temperature (DYG) and that with yogurt fermented at low temperature (DYL) compared to that in DSS-induced colitic mice (DC), especially DYL had higher concentration of cytokines IL-4, and IL-10 than DYG. MPO (myeloperoxidase) tended to decrease more in treatments with yogurt than DC. Additionally, yogurt fermented at low temperature had anti-inflammatory activity, although there was no significant difference with general temperature-fermented yogurt (p>0.05).

• Food Science and Preservation
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• v.21 no.6
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• pp.903-907
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• 2014

For the selection of a starter for vinegar, six strains of acetic-acid bacteria were isolated from traditional Korean vinegar fermented through the static method. These strains were investigated for their acetic-acid fermentation and identification characteristics. The 16S rRNA sequences of six strains were identified as Acetobacter pasteurianus, A. malorum, Gluconacetobacter entanii, Ga. intermedius, and Ga. xylinus respectively. The overoxidation of acetic acid, acetic-acid and pH tolerances, and acetic-acid production of these strains were investigated. None seemed to have been overoxidized. The Gluconacetobacter genus showed acetic-acid tolerance. Among the acetic-acid bacteria, A. malorum V5-7 exhibited the highest pH tolerance. The Ga. intermedius V11-5 and Ga. xylinus V8-1 strains produced colloids that exopolysaccharides of fiber. The acetic-acid production by isolated acetic-acid bacteria and type strain was a achieved at a shaking culture at $30^{\circ}C$ for 5 days. A. malorum V5-7, A. pasteurianus Gam2, and Ga. intermedius V11-5 exhibited the highest acetic acid production. The study results indicate that appropriate strains of acetic-acid bacteria improved the thraditional Korean vinegar fermented through the static method.

• Microbiology and Biotechnology Letters
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• v.40 no.4
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• pp.319-324
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• 2012

Production of liquid starters using wheat bran as a medium for Rhizopus oryzae N174 and the changes in their characteristics noted during storage were investigated in this study. The optimal culture conditions of the liquid starters were determined to be 5~15% (w/v) wheat bran and 48~72 hrs of incubation. The effects of liquid starters with different storage periods and temperatures (-18, 4, 10 and $25^{\circ}C$) on the quality of wheat nuruk were evaluated. According to the results of the pH, acidity, reducing sugar and enzyme activities, it was found that liquid starter using wheat bran preserved for one day, at any temperature, is the best method of storage for seed cultures for R. oryzae N174.

• Food Science and Preservation
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• v.22 no.6
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• pp.851-858
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• 2015

This study was designed to improve the sensory characteristics and mitigate the bitter taste of Platycodon gradiflorum. It was aimed at investigating the qualitative properties of fermented P. gradiflorum after repeated steaming and drying treatments. P. gradiflorum was heated for 2 hr at $95^{\circ}C$, being the first and third treatments compared afterwards. Lactobacillus plantarum, at a concentration of 10%, was used as starter culture. As a result, the third steaming process and the addition of starter improved the physical and chemical properties of P. gradiflorum i.e., crude saponin and total polyphenol contents increased significantly. Moreover, P. gradiflorum steamed three times and fermented by L. plantarum showed the higher overall preference score. Our results indicated that the three-time steaming and drying was an effective manufacturing process for the production of high-quality fermented P. gradiflorum. Lactic acid-fermented P. gradiflorum also could have a potential use as a valuable resource for the development of functional products.

• Culinary science and hospitality research
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• v.9 no.3
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• pp.130-140
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• 2003

The studies were carried out to optimize a new starter for bread fermentation. Two strains of lactic acid bacteria and yeast were isolated from Kimchi. These strains showed good condition for quality bread fermented. The strains identified as Leuconostoc mesenteroides, Lactobacillus brevis, Saccharomyces fermentati and Saccharomyces cerevisiae. The mixed culture of four strains was due to the synergistic effect by interaction of these strains.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.3
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• pp.233-240
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• 1991

Effects of various sub-ingredients (hot pepper, garlic, ginger, green onion, leek, salted and fermented anchovy juice, and sugar) on the sensory quality of Korean cabbage kimchi were investigated. Sixteen sensory attributes were selected and their intensities evaluated by 20 panelists. The kimchi had an unbarmonized taste and unpleasant flavor when fermented with individual sub-ingredients, but had a well harmonized taste when fermented with all sub-ingredients. Hot pepper, ginger and garlic contributed to reduction of the unpleasatnt taste and moldy odor. The strong garlic flavor was reduced by adding green onion and leek. Salted and fermented anchovy juice gave a palatable taste, and the overall taste was improved by adding sugar. All sub-ingredients except sugar reduced the sour tasts.

• Journal of Microbiology and Biotechnology
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• v.33 no.6
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• pp.780-787
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• 2023

Two mannitol producing lactic acid bacteria were isolated from pa (green onion)- kimchi, identified and named as Leuconostoc mesenteroides SKP 88 and Leuconostoc citreum SKP 92, respectively. Both isolates grew well at 25-30℃, initial pH 6-8, and 3% and lower NaCl concentration. Both isolates converted fructose into mannitol efficiently when grown on MRS broth containing fructose and glucose. Glucose was used as a carbon source and fructose was used as a precursor for mannitol. Mannitol yields were the highest in MRS broth with 3% fructose and 2% glucose. Shine muscat juice fermentation was done using each isolate as a starter. As fermentation progressed, decrease in pH and increases in titratable acidity and viable counts were observed. L. mesenteroides SKP 88 showed better mannitol conversion ability than L. citreum SKP 92, and shine muscat juice fermented with L. mesenteroides SKP 88 showed the mannitol production of 41.6 g/l at 48 h, and juice fermented with L. citreum SKP 92 showed 23.4 g/l at the same time. Yogurt fermentations showed similar patterns, and yogurt fermented with L. mesenteroides SKP 88 showed the mannitol production of 15.13 g/l. These results showed that both strains are useful as starters for healthy fermented foods with reduced fructose contents.

• The Korean Journal of Food And Nutrition
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• v.17 no.1
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• pp.8-17
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• 2004

The effect of chlorella extract on the growth and acid production of yoghurt starter was investigated in order to prepare the yoghurt added with chlorella extract. The various levels of chlorella extract powder were added to skim milk medium and the medium was fermented by single or mixed culture of 4 types of lactic acid bacteria such as Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus casei, and Lactobacillus bulgaricus. The changes in acid production(pH, titratable acidity) and number of viable cells of the medium during fermentation in skim milk added with chlorella extract powder have determined. When chlorella extract powder was added to skim milk medium at the levels of 0.5%, 1.0%, 2.0%, and 3.0%, the addition of 0.5% chlorella extract powder with the single culture of Str. thermophilus, Lac. casei, and Lac. bulgaricus showed the highest number of viable cell counts after 9 hours incubation. And also all single cultures of the yoghurt starter produced the higher amounts of acid with the addition of 0.5% chlorella extract powder. When chlorella extract powder was added to the medium at the levels of 0.25%, 0.5%, 1.0%, and 2.0%, the addition of lower lever(0.25∼0.5%) of chlorella extract powder with the mixed culture of the lactic acid bacteria showed more the acidity of pH and the number of viable cell counts. Among the treatments tested, the addition of 0.25% chlorella extract powder with the mixed culture of Str. thermophilus and Lac. casei produced the highest number of viable cell counts after 12 hours incubation. Therefore it was suggested to manufacture the yoghurt with the addition of 0.25% chlorella extract powder and the inoculation of mixed culture of Str. thermophilus and Lac. casei for on the stimulation of growth of the yoghurt starter.