• Journal of Microbiology and Biotechnology
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• v.10 no.4
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• pp.507-513
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• 2000

A bacteriocin-producing organism, Enterococcus sp. T7, was isolated from human fecal samples. Bacteriocin T7, named tentatively as the bacteriocin, was produced by Enterococcus sp. T7 and it inhibited some strains of Lactobacillus. Staphylococcus, Enterococcus, and Streptococcus, but not all the lactococci and gram-negative bacteria tested. Bacteriocin T7 inhibited the growth of Listeria monocytogenes Scott A, but the degree of inhibition was less than those for other sensitive gram-positive vacteria. Bacteriocin T7 in MRS broth started to produce at the middle of the exponential growth phase and the inhibitory activity reached its maximum level during the stationary growth phase. Bacteriocin T7 was stable against heat treatments, pH variations (pH 2-10), and exposure to organic solvents. The molecular weight of bacteriocin T7 was estimated to be 6.500 Da by SDS-PAGe. All these facts, including physico-chemical stabilities, small molecular size, and inhibition of Kisteria monocytogenes, indicate that bacteriocin T7 is likely to be a member of the class IIa bacteriocins.

• The Korean Journal of Food And Nutrition
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• v.11 no.6
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• pp.683-688
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• 1998

This study was conducted to develop optimal composition of flour brew in order to economically utilize flour brew inoculated by lactic acid bacteria as a starter(mother sponge) in bread-making. Two flour brews were prepared ; one with flour and water, the other with flour, water and NaCl. Various nutrients were added to both flour brews and Lactobacilli deMan Rogosa and Sharpe (MRS) broth to investigate the effect of them on growth and activities of Streptococcus thermophilus, Lactobacillus brevis and their mixed culture in flour brews to be tested with incubation at 37$^{\circ}C$. The growth of Streptococcus thermophilus, Lactobacillus brevis and their mixed culture was stimulated by addition of NaCl with 0.85% concentratin and more by mixed culture than by single lactic acid bacteria, resulting in 3 hrs reduction in cultivation and more by mixed culture than by single lactic acid bacteria, resulting in 3 hrs reduction in cultivation time. the addition of 3% glucose to flour brew with NaCl was observed to enhance acid productioni by mixed culture. Yeast extract greatly affected growth and activities of mixed culture of lactic acid bacteria in flour brew with NaCl and its optimum level of this additive in flour brew with NaCl was approximately 1.0%. The optimal composition of flour brew for mixed culture of lactic acid bacteria was suggested as follows; flour 100g, water 300g, NaCl 3.46g, glucose 12.48g, yeast extract 3.46g.

• Microbiology and Biotechnology Letters
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• v.26 no.5
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• pp.373-378
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• 1998

This study was performed to investigate antimicrobial effects and their actions of the ethanol extracts of 12 spices against Lactobacillus plantarum and Leuconostoc mesenteroides, which are related to Kimchi fermentation. The cardamon, thyme, and cumin ethanol extracts among 12 spices showed antimicrobial activities against Lac. plantarum, not against Leu. mesenteroides through paper disc method. The growth of Lac. plantarum was inhibited in MRS broth containing each extracts of cardamon (>4%), thyme (>4%) and cumin (>1%). SDS-PAGE and transmission electron micrographs showed that the cell walls and membranes were disrupted and the cytoplasmic components were leaked in strains treated with ethanol extracts.

• Journal of Animal Science and Technology
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• v.58 no.3
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• pp.10.1-10.10
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• 2016

Background: Airag, alcoholic sour-tasting beverage, has been traditionally prepared by Mongolian nomads who naturally ferment fresh mares' milk. Biochemical and microbiological compositions of airag samples collected in Ulaanbaatar, Mongolia and physiological characteristics of isolated lactic acid bacteria were investigated. Methods: Protein composition and biochemical composition were determined using sodium dodecyl sulfate-gel electrophoresis and high performance liquid chromatography, respectively. Lactic acid bacteria were identified based on nucleotide sequence of 16S rRNA gene. Carbohydrate fermentation, acid survival, bile resistance and acid production in skim milk culture were determined. Results: Equine whey proteins were present in airag samples more than caseins. The airag samples contained 0.10-3.36 % lactose, 1.44-2.33 % ethyl alcohol, 1.08-1.62 % lactic acid and 0.12-0.22 % acetic acid. Lactobacillus (L.) helveticus were major lactic acid bacteria consisting of 9 isolates among total 18 isolates of lactic acid bacteria. L. helveticus survived strongly in PBS, pH 3.0 but did not grow in MRS broth containing 0.1 % oxgall. A couple of L. helveticus isolates lowered pH of skim milk culture to less than 4.0 and produced acid up to more than 1.0 %. Conclusion: Highly variable biochemical compositions of the airag samples indicated inconsistent quality due to natural fermentation. Airag with low lactose content should be favorable for nutrition, considering that mares' milk with high lactose content has strong laxative effect. The isolates of L. helveticus which produced acid actively in skim milk culture might have a major role in production of airag.

• Microbiology and Biotechnology Letters
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• v.25 no.2
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• pp.229-234
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• 1997

Shizandra chinensis(SC) and Pinus regida(PR) showed antimicrobial activity against 3 strains(B-5, D-1, A-1) of lactic acid bacteria(LAB) isolated from kimchi among eight kinds of plant extracts such as Shizandra chinensis, Phellodendron amurense, ornus officinalis, Pinus regida, Allium tuberosum, Machilus thunbergii, Cyperus rotundus and Schizonepeta tenuifloia. The growth of LAB was inhibited apparently in modified MRS broth containing 1% Schizandra chinensis at $35^{\circ}C$. Pinus regida showed weaker inhibitory effect on the growth of isolated LAB than Shizandra chinensis. pH of SC added kimchi did not change greatly compare with control during 25 days of fermentation. Degree of titratable acidity change and ratio of reducing sugar utilization in control were more higher than in SC added kimchi during fermentation. Growth of total bacteria and lactic acid bacteria was inhibited about 1 to 2 $log_10$ cycle by addition of SC extracts during kimchi fermentation for 10 days at $10^{\circ}C$. Fermentation of kimchi was delaved about 5 to 7 days by addition of 1 or 2% of SC. extract, but sensory quality (falvor, taste and overall acceptability) of SC added kimchi was lower than that of control (p>0.05).

• Korean Journal of Agricultural Science
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• v.38 no.3
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• pp.473-477
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• 2011

A number of health benefits have been claimed for probiotic bacteria such as Bifidobacterium (B) spp. Lactobacillus(L) acidophilus, and Lactococcus(Lc) cremoris. Viability of probiotic bacteria is important in order to provide health benefits. Only a limited culture media for the test purpose of probiotic bacteria are commercially available (MRS broth), but the media for large-scale propagation of viable cells which are able to be used as food additive are not available. The manufacture of a low priced and preferred novel medium for probiotic bacteria was therefore, attempted using whey protein concentrate(WPC) and Makgeolli sludge as a starting material. The effect of WPC and Makgeolli sludge on the growth of four strains (B. bifidum 15696, B. longum 15707, L. acidophilus CH-2, and Lc. cremoris 20076) was investigated. Medium prepared such as WPC, Makgeolli sludge, and WPC+Makgeolli sludge(WPCMs). It was observed that the growth of 4 strains (B. bifidum 15696, B. longum 15707, L. acidophilus CH-2, and Lc. cremoris 20076) was stimulated by Makgeolli sludge, WPC, WPCMs. Especially, Viable cell number of 4 strains in the WPCMs were higher than that of the single media. These result suggest the possibility that Makgeolli and WPC, acts as a growth factor for the growth of probiotic bacteria.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.3
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• pp.344-348
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• 2006

This study was carried out to survey the effect of medicinal herbs on the growth of 3 strains of lactic starter cultures in MRS broth by the addition of 0, 1, 3, 5, and 10% water extract, after 30 hrs incubation. The pH, titratable acidity and O.D. of lactic acid bacteria were investigated to obtain fundamental knowledge for the development a new product. The effects of medicinal herbs extracts on the growth of lactic acid bacteria were variable depending upon the species of lactic acid bacteria and medicinal herbs extract. Growth of Str. thermohilus was activated by addition of 1 and 3% Angelica gigas water extract, but the basal medium plus 5 and 10% extract and growth of L. acidophilus and Bif. longum were depressed by the addition of extract. The pH and acid production ability dropped slightly in the basal medium plus 1 and 3% of extract. The other samples following the same trend as the control.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.3
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• pp.357-363
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• 2006

This study examined the effect of medicinal herbs on the growth of 3 strains of lactic starter cultures in a MRS broth by adding a 0, 1, 3, 5, and 10% water extract. The pH, titratable acidity and OD of lactic acid bacteria were investigated in order to obtain fundamental knowledge for the development a new product, box thorn yogurt. In the case of adding the Acanthopanax sessiliflorum Seeman water extract, Streptococcus thermophilus was largely activated by the addition of the 5% extract. The growth of Lactobacillus acidophilus was activated by the extracts but it was depressed by the addition of the 3% Acanthopanax sessiliflorum Seeman water extract. Compared with the control, the growth of Bifidobacterium longum was largely activated by the addition of the 10% extract but it was depressed by the addition of the 5% Acanthopanax sessiliflorum Seeman water extract.

• Journal of Food Hygiene and Safety
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• v.14 no.3
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• pp.233-237
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• 1999

The bacteriocin produced by Lactobacillus sp. GM7311 was purified by sequential steps including n-propanol/acetone treatment, CM-cellulose chromatography, and gel filtration on Sephacryl HR-100. The relative activity of bacteriocin increased 493-fold after final purification step with a recovery of 8.3%. Two protein bands of ca. 8,200 and 2,500 were detected by SDSPAGE of bacteriocin purified through CM-cellulose and sephacryl HR-100 chromatography and both of them had bacteriocin activity.

• Food Science of Animal Resources
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• v.30 no.5
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• pp.795-803
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• 2010

A DF01 strain that inhibits tyramine-producing Lactobacillus curvatus KFRI 166 was isolated from Dongchimi, a traditional Korean fermented vegetable, and identified as Lactobacillus brevis by biochemical analysis and reverse transcriptase sequencing of 16S rRNA. The antimicrobial compound produced by L. brevis DF01 was secreted at a maximum level of 640 AU/mL in late exponential phase in MRS broth, and its activity remained constant during stationary phase. The activity of bacteriocin DF01 was totally inactivated by $\alpha$-chymotrypsin, pronase E, proteinase K, trypsin, and $\alpha$-amylase, but not by catalase, which indicates the compound was glycoprotein in nature. The activity was not affected by pH changes ranging from 2 to 12 or heat treatment (60, 80, and $100^{\circ}C$ for 30 min), but was reduced after autoclaving. Bacteriocin DF01 had bacteriolytic activity and a molecular weight of approximately 8.2 kDa, as shown by tricine-SDS-PAGE analysis. Therefore, bacteriocin DF01 can be used in the manufacture of fermented meat products due to its inhibition of tyramine-producing L. curvatus and non-inhibition of L. sake, which is used as a starter culture for meat fermentation.