• The Korean Journal of Food And Nutrition
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• v.15 no.1
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• pp.42-50
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• 2002

This experiment was carried out to investigate the effect of Maesil extract on the acid production and growth of yoghurt starter in the skim milk medium. The Maesil extract was added to skim milk medium fur 1% to 9% and the medium was fermented by single or mixed culture of 4 types of lactic acid bacteria(Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus, bulgaricus, Lactobacillus casei). The chemical composition of Maesil, the changes in acid production (titratable acidity, pH) and number of viable cells of the medium during lactic fermentation in skim milk added with Maesil extract, and the keeping quality of curd yoghurts containing Maesil extract have determined. The composition of Maesil were 0.4% crude ash, 4.1% dietary fiber, 4.66%l citric acid, 0.264% total sugars and 405.34mg% vitamin C. The addition of Maesil extract stimulated the acid production and propagation of the lactic acid bacteria. Among the treatments tested, the addition of 3% Maesil extract with the mixed culture of Streptococcus thermophilus, Lactobacillus acidophilus and Lactobacillus casei produced the highest amount of acid(1.23%) and showed the highest number of viable cell counts(3.6$\times$10$^{11}$ cfu/mL). When the curd yoghurts containing 3% Maesil extract with the mixed culture of the lactic acid bacteria were kept at 4$^{\circ}C$ and 2$0^{\circ}C$ for 30 days, it was showed that the changes of titratable acidity, pH and number of viable cell counts of the lactic acid bacteria were not significantly different during storage. Therefore the keeping quality of the curd yoghurts adding 3% Maesil extract showed relatively good at the shelf-life.

• Food Science of Animal Resources
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• v.28 no.1
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• pp.82-90
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• 2008

Two strains of pure lactic acid bacteria capable of forming both acid and slime were isolated from the kefir made of goat milk. The isolated strains observed by morphological and physiological properties, and their 16S rDNA partial sequence were identified as Streptococcus salivarius subsp. thermophilus(LFG-1) and Lactococcus lactis subsp. lacits(LFG-2) with over 99% homology. The optimum temperature of Str. salivarius subs. thermophilus LFG-1 for growth was $40-45^{\circ}C$, and its generation time was 40.6 minutes. The final pH of cultured broth by Str. salivarius subsp. thermophilus LFG-1 and the commercial strain Str. thermophilus Body-1 for 24hr at $37^{\circ}C$ were 4.30 and 4.55, respectively. The coagulative activity of Str. salivarius subsp. thermophilus LFG-1 was almost as strong as that of commercial strain Str. thermophilus Body-1. However, the LFG-2 strain showed lower coagulative activity than Str. thermophilus Body-1. The survival rate of lactic acid bacteria were between 22-29% in 0.3% bile extract. At pH 1.0 all of the bacteria were killed, and most of lactic acid bacteria died against pH 3.0. However, all lactic acid bacteria survived well at pH 4.5.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1414-1417
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• 2000

This study was to investigate effects of the supplementation of the different lactic acid bacteria[Streptococcus thermophilus KCTC 2185 culture group(ST), autoclaved Streptococcus thermophilus KCTC 2185 culture(STS), Lactobacillus acidophilus ATCC 4356 culture group(LA) and autoclaved Lactobacillus acidophilus ATCC 4356(LAS)] on suppression of aluminum accumulation in organs of rats fed with the diet containing $250\;{\mu}g/g$ aluminum sulfate for 4 weeks. Amount of aluminum accumulation in the control rat was in order of bone>lung>heart>large intestine>kidney>liver>brain>small intestine. Effects of reduction of aluminum accumulation by feeding of the four difference fermented milk were in order of LA group>LAS group>ST group>STS group. ST and LA both were more effective than STS and LAS. Ultimately fermented milk was useful in reduction of toxication by accumulating of aluminum in vivo.

• Journal of the East Asian Society of Dietary Life
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• v.26 no.6
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• pp.491-497
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• 2016

The objective of this research was to determine the fermentation and quality properties of soy yogurt incorporating insoluble components fermented with Streptococcus thermophilus (S. thermophilus) and Lactobacillus bulgaricus (L. bulgaricus) for 24h. Boiled soybeans were ground and reconstituted into equivalent total solids (18%). After soymilk was homogenized with sugar, it was pasteurized in a water bath at $90^{\circ}C$ for 30 min. Two kinds of lactic acid bacteria were inoculated into two types of soymilk after cooling down $40{\sim}45^{\circ}C$ and fermentation at $37^{\circ}C$ for 24h. Titrable acidity, pH, viscosity, sugar content, and number of viable cells were determined in triplicate. Soy yogurt fermented with L. bulgaricus did not reach pH 4.5, where as S. thermophilus was considered good for achieving pH 4.08 and titratable acidity of 2.27% for 24 h. Soy yogurt fermented with S. thermophilus had a higher viscosity and lower sugar contents than that fermented with L. bulgaricusas incubation time increased. Total viable count was $1.80{\times}10^{10}CFU/mL$ on S. thermophilus and $2.16{\times}10^8CFU/mL$ on L. bulgaricus after 24 h at $37^{\circ}C$. However, there was no significant difference in sensory intensities and preference between the two samples. As a result, S. thermophilus was identified as a better culture than L. bulgaricus for the manufacture of soy yogurt incorporating insoluble components.

• 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.23 no.4
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• pp.373-377
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• 1995

We investigated the survival, $\beta$-galactosidase activity and cellular permeability of lactic acid bacteria such as Lactobacillus acidophilus ATCC 4356, Lactobacillus casei subsp. casei IFO 3533, Streptococcus thermophilus KCTC 2185, Lactobacillus delbrueckii subsp. lactis ATCC 4797, and Lactobacillus delbrueckii subsp. bulgaricus ATCC 11842 in anaerobic condition of pH 1.5-3.5 range. Numbers of all tested viable cells did not decrease at pH 3.5, but decreased rapidly at pH 1.5 and pH 2.5 during 2 hour incubation at modified EG medium. Immediately after 2 hour incubation, the decrease in population at pH 1.5 and pH 2.5 was about 6-8 and 5-7 log cycles/ml, respectively. Lactobacillus acidophilus ATCC 4356 showed the higest survival of all tested bacteria. The $\beta$-galactosidase activity from Lactobacillus delbrueckii subsp. bulgaricus ATCC 11842 and Streptococcus thermophilus KCTC 2185 decreased rapidly at pH 1.5 and 2.5, but there was a little decrease at pH 3.5. The cellular permeability that was measured by the leakage of intracellular materials increased with decrease of pH. These results suggest that the ingested lactic acid bacteria may be destroyed in contact with low pH of gastric acid.

• The Korean Journal of Food And Nutrition
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• v.35 no.5
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• pp.332-342
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• 2022

Nonalcoholic fatty liver disease (NAFLD) is recognized one of the leading metabolic diseases globally, and the younger age population with the disease is rapidly growing, especially in developed countries. Since there has been no approved medicine, losing weight is known to be the only best remedy to control or reverse the disease. Recently, the field of microbiome has attracted much attention to offer more practical choices for patients. Here, we provide experimental evidence that Streptococcus thermophilus LM1012 (LM1012), a safe probiotic strain, is effective for improving NAFLD indexes. In the methionine-choline deficient (MCD) diet induced C57BL/6 mouse model, administration of LM1012 promoted marked reductions of aspartate transaminase (23.8%), total bilirubin (27.8%), hydroxycholesterol (64.2%), triglyceride (29.7%) and IL-1β (68.3%) compared to the MCD diet alone group. Also, the histopathological data imply that LM1012 inhibited fat accumulation and inflammation in the liver, which are the key biomarkers for progression of the disease. Together, these findings suggest that human consumption of LM1012 as a healthy nutritional supplement, may be helpful in reducing the risk of liver damages in NAFLD patients.

• Current Research on Agriculture and Life Sciences
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• v.3
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• pp.151-157
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• 1985

This study was carried (Jut to find out changes of ${\gamma}$-globulin and cholesterol of rat blood fed on yoghurt and Koumiss. Yoghrt and koumiss were manufactured with fortifed milk and Lactobacillus bulgaricus, streptococcus thermophilus and Saccharomyces fragilis were used. The twenty rats were devised into 4 groups with 5 replications by completely randomized design. The experimental groups are the control, milk, yoghrt and koumiss feeding groups. The results are summerized as follows ; The changes of pH after 8hrs incubation with Lactobacillus bulgricus, Streptococcus thermophilus and the mixed strains were 3.7, 4.6 and 3.5 at $42^{\circ}C$, respectively. Average alcohol percentage of Koumiss was 1.2 (%). The average viscosity of yoghurt and Koumiss with milk showed 1500 cp and 390 cp. respectively at 11 % of milk total solid. ${\gamma}$-globulin contents in blood of rat fed on yoghurt and Koumiss were higher than those of control and milk. Cholesterol of rat blood in yoghurt and Koumiss group were lower than those of control and milk group.

• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.47-55
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• 1995

New type yogurts were prepared by fermenting whole milk containing soy milk and/or brown rice with single or mixed culture of 4 types of lactic acid bacteria(Lactobacillus acidophilus, Lactobacillus bulgaricus, Leuconostoc mesenteroides, Streptococcus thermophilus). The curd yogurts were evaluated by acid production (pH, titratable acidity), number of viable cell, keeping quality and sensory property. Addition of soy milk and brown rice markedly stimulated the acid production and propagation of lactic acid bacteria, and slightly increased the Brix degree. Among the organisms tested, the mixed culture of Leuconostoc mesenteroides and Streptococcus thermophilus produced the highest amount of acid, and that of Leuconostoc mesenteroides and lactobacillus acidophilus showed the highest number of viable cell counts. When curd yogurt added with soy milk and brown rice was kept at $3^{\circ}C$ for 15 days, its keeping quality was relatively good. The sensory evaluation showed that the curd yogurt containing soy milk and brown rice slightly reduced the texture property and overall acceptability comparing with milk yogurt.

• YAKHAK HOEJI
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• v.48 no.1
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• pp.47-54
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• 2004

ClpP is a stress-inducible protein and proteolytic subunit of the ATP-dependent Clp protease in prokaryotes and eukaryotes. Although its physiological roles in bacterial virulence were widely studied in various organsims, including Streptococcus pneumoniae, until now the immunological effect has not been investigated. Here, we have examined the cross reactivity of S. pneumoniae ClpP antibody with other organisms's cell lysate proteins. Although the protein sequence of S. pneumoniae ClpP was highly conserved among various organisms including human, the antibody rasised by S. pneumoniae ClpP was not cross-reacted with other organism's cell lysates, which were Saccharomyces cerevisiae , human lung A549 cell, Bacillus subtilis, Pseuomonas aeruginosa, E. coli, and Salmonella typhi. It was only reacted with S. pneumoniae and Lato-bacillus thermophilus. Thus we examined the immunoprotective effect of ClpP by immunizing mice with the purified ClpP. The mean survival time of mouse was significantly increased with the ClpP immunization. These results suggest that S. pneumoniae ClpP could be used as a vaccine candidate for prevention of S. pneumoniae infection.