• Journal of Microbiology and Biotechnology
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• v.9 no.1
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• pp.22-31
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• 1999

Saccharomyces fermentati and Leuconostoc mesenteroides were isolated from a traditional kimchi, and then the Leu. mesenteroides was mutated to the acid-tolerant mutant Leu. mesenteroides M-l00. In the result of growth properties in MRS broth with various pHs adjusted with HCl and acid solution (latic acid:acetic acid=1:2), an acid-tolerant mutant Leu. mesenteroides M-100 showed more increased ability for growth than its wild strain at various temperatures. The strains were used as starters for the fermentation of kimchi. The experiments were performed with classified experimental groups (Group I, control kimchi; Group II, addition of YK-19 only; Group III, addition of M-100 only; Group IV, addition of mixture of M-100 and YK-19), and their pH, total acidity, reducing sugars content, organic acid productivity, organoleptic tests, and microfloral changes were compared. As a result, in pH and acidity, the optimal ripening period of Group IV was about 13.5 days (i.e. from the 8.5 to 22 days of fermentation). This result indicates that the optimal ripening period of Group IV was about 1.5 times longer than that of Group I. Furthermore, Group IV was edible to 28 days of fermentation. In addition, high contents of succinc acid was observed in Group IV. Group IV was also highly ranked on the organoleptic test. During the fermentation of kimchi, the number of Leuconostoc sp. in group I reduced after 7 days; however, the number of Leuconostoc sp. in Group II, III, and IV decresed after 14 days of fermentation. An especially high number of Leu. sp. was observed in Group IV, and this gave better flavor of kimchi than any other during the whole fermentation period. Citric acid, tartaric acid, succinic acid, fumaric acid, and lactic acid were detected in the kimchi, and a significant increase in the concentration of lactic acid during fermentation was observed in the all experimental groups.

• Journal of Microbiology and Biotechnology
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• v.28 no.11
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• pp.1834-1845
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• 2018

The lactobacilli associated with a fermented goat milk product from Tajikistan were isolated to characterize their technological properties and antibiotic resistances in order to assess their suitability for development as starter cultures. In this study, twenty three strains were identified by 16S rRNA sequencing as typical dairy-associated lactic acid bacterial strains, i.e. L. plantarum, L. pentosus, L. delbrueckii, L. helveticus and L. paracasei. These strains were generally susceptible to most antibiotics tested in this study and this allowed a selection of strains as safe starters. The draft genomes of four representative strains were sequenced and the number of contigs of the four assembled genomes ranged from 51 to 245 and the genome sizes ranged from 1.75 to 3.24 Mbp. These representative strains showed differences in their growth behavior and pH-reducing abilities in in vitro studies. The co-inoculation of these Lactobacillus spp. strains together with a yeast Kluyveromyces marxianus MBT-5698, or together with the yeast and an additional Streptococcus thermophilus MBT-2, led to a pH reduction to 3.4 after 48 h. Only in the case of fermentation inoculated with the co-culture, the viscosity of the milk increased noticeably. In contrast, fermentations with single strains did not lead to gelation of the milk or to a decrease in the pH after 24h. The results of this study provide a comprehensive understanding of the predominant lactobacilli related to Tajikistani fermented milk products.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.1
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• pp.1-7
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• 1997

In order to utilize fish by-products from the skipjack tuna (Katsuwonus pelamis) canning manufactures Lactobacillus buigaricus KCTC 3188 and L. piantarum KCTC 1048 were used as a starter culture for the preparation of fermented fish silage with skipjark tuna viscera. The optimum temperature and pH on barterial growth and lactic acid production of L. bulgaricus and L. plantarum in MRS broth were $35^{\circ}C$ and around pH 6.0, respectively. And the optimum concentrations of the carbohydrate sources added to the broths were $7\%$ for dextrose and $10\%$ for molasses on the basis of total weights of skipjack tuna viscera. The pH of acid treated skipjack tuna viscera silage (ASS) slightly increased from 4.0 to 4.5, while that of fermented skipjack tuna viscera silages by the use of lactic acid bacterias (FSS) was significantly declined from 5.9 to about 40 after 42 days of storage at $35^{\circ}C$. Though the content of volatile basie nitrogen (VBN) in ASS was lower than those of FSS after 42 days of storage at $35^{\circ}C$, VBN content in silages slightly increased from an initial value of $62\~65{\cdot}mg/100g$ to final value of $113\~155\;mg/100g$ over 42 days. The fermented silage by L. piantarum reached a maximum concentration of amino nitrogen and showed $81\%$ of hydrolysis degree after 4 days of storage at $35^{\circ}C$.

• Microbiology and Biotechnology Letters
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• v.35 no.4
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• pp.304-309
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• 2007

Soybean is useful source of protein, especially in Asia. But soybean needs heat inactivation or fermentation process before consumption, since it contains the toxic lectin and various protease inhibitors. Therefore, production of soybean boiling-waste liquor (SBWL) as a byproduct is inevitable. In this study, the chemical composition of SBWL and the optimization of culture conditions for Bacillus pumilus JB-1, a selected strain for functional chungkuk-jang fermentation, using SBWL were investigated. The SBWL contains 88% water, 9.5% free sugar, 1.6% crude protein, 0.3% crude fat, 0.1% crude fiber and 2.1% ash, respectively. The contents of total polyphenol, total flavonoids and free amino acid in SBWL were 55%, 76%, and 30% of those of raw soybean, respectively. Culture conditions for B. pumilus JB-1 in SBWL were optimized. The 1/10-diluted, 0.1 % of $(NH_4)_2SO_4$ added SBWL without pH adjustment and carbon source addition was cultured at $37^{\circ}C$ for 48 h with agitation (120 rpm). The 0.5% of inoculation was enough. The large scale fermentation in 5-L jar fermentor showed that the SBWL is a good resource for production of chungkuk-jang starter and functional ingredients.

• Food Science and Preservation
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• v.23 no.4
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• pp.568-575
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• 2016

Bacillus amyloliquefaciens CGD3 was used as a starter for fermentation of amaranth and cultural characteristics and biological activities of amaranth were investigated. The viable cells in fermented amaranth was 4.54~8.01 log CFU/mL during 96 hr of fermentation period. Protease activities of amaranth showed the highest by 36.7 unit/mL after 72 hr of fermentation. The total phenolic and flavonoid contents of amaranth increased with fermentation time while its total sugar content decreased. The total protein content was the highest in amaranth fermented for 96 hr (0.25 mg/g). The DPPH scavenging activities, FRAP (ferric reducing antioxidant power), and reducing power of amaranth were highest in amaranth fermented for 72 hr, showing 84.46%, $551.91{\mu}M$, and 2.74, respectively. ACE (angiotensin converting enzyme) and ${\alpha}$-Glucosidase inhibition rates increased with fermentation time and showed the highest after 72 hr.

• Korean Journal of Microbiology
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• v.51 no.4
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• pp.407-418
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• 2015

This study is focused on establishing the optimal conditions to enhance the production of antilisterial substances by Lactobacillus paracasei BK57 isolated from Baikkimchi. In addition, the growth and in situ lactic acid and bacteriocin production of this strain were investigated during the manufacture of fresh cheese. And then the efficacy of using Lactobacillus starter as a protective culture to improve the safety of fresh cheese against Listeria monocytogenes KCTC 3569 was estimated. Maximum growth rate and activity of antibacterial substances were obtained in Lactobacilli MRS broth at $37^{\circ}C$ with controlled pH 6.0 after 30 h of incubation under aerobic condition. However, the growth rate and antimicrobial activity of bacteriocin produced in whole milk supplemented with yeast extract (2.0%) as a substrate were lower than those obtained in MRS broth. Live cells and cell-free culture supernatant of BK57 strain were effective in the suppression of L. monocytogenes in milk, whereas the inhibitory of the bacteriocin obtained from BK57 strain was higher in BHI broth than in milk. During storage at $4^{\circ}C$ and $15^{\circ}C$ for 6 days, no significant difference was found in the cell viability and antimicrobial activity of BK 57 strain in fresh cheese. In samples held at two temperatures, there was at least a 15% reduction in the numbers of the pathogen in fresh cheese artificially contaminated with approximately $10^5CFU/ml$ of L. monocytogenes within 6 days. Our results demonstrated the usefulness of L. paracasei BK57 having antilisterial activity as a biopreservative in the cheese making process.

• Korean Journal of Microbiology
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• v.48 no.2
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• pp.147-155
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• 2012

To improve of the quality of Korea traditional wheat-rice wine (makgeolli) production, we used a rice fermentation starter (rice nuruk) made by inoculation of Rhizopus oryzae CCS01 which was isolated and selected from commercial nuruk. Amylase activity of a rice nuruk was 1.8-2.4 times higher than those of commercial nuruks. The best acceptability of wheat-rice wine in a sensory test was observed at 4 : 6 ratio of wheat-rice mash at experimental condition. During the fermentation period, pH of wheat-rice makgeolli made with a rice nuruk was higher compared to those made with commercial nuruks such as Sanseong, Jinju, and Songhak. Acidity of makgeolli mash was lower in case of using a rice nuruk and birx and alcohol production were higher compared to those of makgeolli mash using commercial nuruks. Highest alcohol production was observed at makgeolli mash using a rice nuruk and 12% of alcohol was produced at fermentation end. These results suggest that production of a new type of wheat-rice makgeolli using a rice nuruk was possible.

• Journal of Environmental Science International
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• v.25 no.6
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• pp.789-798
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• 2016

Lactic acid bacteria (LAB) are industrially important microorganisms for probiotics. The recent widespread application of LAB for preparation of functional food is attributable to the accumulating scientific evidence showing their beneficial effects on human health. In this study, we isolated and characterized plant-derived LAB that show angiotensin-converting enzyme (ACE) inhibitory and antioxidant activities. The selected strain K2 was isolated from Kimchi, and identified as Lactobacillus plantarum by 16S rRNA gene analysis. The strain grew under static and shaking culture systems. They were also able to grow in different culture conditions like $25^{\circ}C{\sim}37^{\circ}C$ temperature, 4~10 pH range and ~6% NaCl concentration. L. plantarum K2 was highly resistant to acid stress; survival rate of the strain at pH 2.5 and 3 were 80% and 91.6%, respectively. The strain K2 also showed high bile resistance to 0.3% bile bovine and 0.3% bile extract with more than 74% of survival rate. The cell grown on MRS agar plate containing bile extract formed opaque precipitate zones around the colonies, indicating they have bile salt hydrolase activity. The strain showed an inhibitory activity against pathogenic bacteria such as Escherichia coli, Staphylococcus aureus and Listeria monocytogenes; antibacterial activity was probably due to the lactic acid. The K2 strain showed relatively higher autoaggregation values, antihypertensive and antioxidant activities. These results suggest that L. plantarum K2 could be not only applied as a pharmabiotic for human health but also is also starter culture applicable to fermentative products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.5
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• pp.721-726
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• 2012

Lactic acid bacteria (LAB) are able to secrete antimicrobial peptides called bacteriocins, which inhibit other bacteria such as pathogenic microorganisms. Therefore, bacteriocin-producing starters can be used as natural biopreservatives for various foods. The objective of this study was to screen and characterize bacteriocin-producing LAB from Kimchi and to investigate their applicability as a starter in Kimchi fermentation. To screen bacteriocin-producing LAB, gram-positive and gram-negative bacteria were used as indicators. To measure the antimicrobial activities of isolates, agar well diffusion assay method was used. According to the results, bacteriocin produced by $Lb.$ $sakei$ B16 showed antimicrobial activity against $Listeria$ $monocytogenes$ ATCC 19115, $Escherichia$ $coli$ KCTC 1467, and$Lactobacillus$ $plantarum$ KTCT 3104. Furthermore, bacteriocin was very stable after treatment with high temperature and high and low pH, but its effects were inhibited by treatment with proteolytic enzymes such as trypsin, proteinase K, and ${\alpha}$-chymotrypsin, revealing their bacteriocin-like protein- based structure. These results suggest that $Lb.$ $sakei$ B16 and its bacteriocin are good candidates as a functional probiotic and natural biopreservative, respectively, in fermented foods.

• Korean Journal of Poultry Science
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• v.34 no.3
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• pp.165-172
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• 2007

We investigated the effects of dietary supplements of probiotics, illite, active carbon and hardwood vinegar on growth performance, feed intake, and pH, shear force, sensory evaluation, meat color and fatty acid composition of meat in broilers. Two hundred broilers were fed diets for five weeks containing 0.2% of probiotics (T1), and 1% of Illite (T2), 1% active carbon (T3), or 1% hardwood vinegar (T4). Body weight gain was higher in T1 and T4 groups fed the starter diet but was the lowest in C and T4 for finishing period (P<0.05). Feed efficiency was not significantly different. In proximate composition, crude fat content of chicken meat were decreased lower in all treatment groups than control, but moisture, crude protein and crude ash were not significantly different. Cooking loss was decreased in T3 and T4 and WHC (water holing capacity) was increased in T3 and T4 groups compared to the other groups. In sensory evaluation, T4 tended to improve the hardness. Redness $(a^*)$ and yellowness $(b^*)$ were no difference between the all treatment groups, lightness $(L^*)$ were higher in T1, T2, T3 and T4 groups than control group (P<0.05). Stearic acid content was lower in T1, T2, T3 and T4 groups, but oleic acid contents were higher in T1, T2, T3 and T4 groups (P<0.05). These results showed that supplementing broiler diets with 1.0% hardwood vinegar may noticeably improve the meat quality of broiler.