• 한국미생물·생명공학회지
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• 제23권5호
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• pp.513-518
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• 1995

To evaluate bile salt-tolerance of lactic acid bacteria (LAB, Lactobacillus acidophilus ATCC 4356, Lactobacillus casei IFO 3533, Streptococcus thermnophilus KCTC 2185, Lactobacillus lactis ATCC 4797, and Lactobacillus bulgaricus ATCC 11842), We investigated the survivals, acid production and $\beta $-galactosidase activity of LAB under anaerobic broth system. Cellular permeability of LAB and their cellular retention of $\beta $-galactosidase were also examined in the same system. Although the growth of LAB was slightly suppressed by 0.3% bile salt, they showed normal growth curve. Streptococcus thermophilus KCTC 2185 was significantly more resistant to bile salt than the others. The $\beta $-galactosidase activity from Streptococcus thermophilus KCTC 2185 and Lactobacillus bulgaricus ATCC 11842 and their cellular retention of $\beta $-galactosidase decreased by 0.3% bile salt. The cellular permeability of LAB in the presence of bile salt increased significantly.

• 한국미생물·생명공학회지
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• 제25권2호
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• pp.218-223
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• 1997

For the utilization of animal blood produced in slaughter for the cultivation of lactic acid bacteria, the nitrogen sources in a complex(MRS) medium were replaced by blood plasma proteins. Focusing the purpose on the industrial production of a probiotics, the hydrolytic activities of three industrially applicable proteases were compared for the effective digestion of the proteins, and Alcalase(the product of Novo Nordisk) was selected with comparatively high activity. The growth of Streptococcus thermophilus KCCM12020 was best among the four strains of lactic acid bacteria tested. With Alcalase-digested proteins in the medium, the growth rates and the final cell concentrations were higher than those with non-digested proteins. The cell mass produced in the medium containing blood proteins as nitrogen sources, $2.5{\times}10^9$ CFU/ml, was significantly high and about 70% of that in MRS medium, showing a great possibility for the utilization of animal blood proteins as economic nitrogen sources in the production of cell mass of lactic acid bacteria.

• 한국미생물·생명공학회지
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• 제23권2호
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• pp.214-219
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• 1995

In fermentation of dairy products, bifidobacteria is used in conjunction with other lactic acid bacteria, such as L. acidophilus, L. bulgaricus and S. thermophilus, rendering the enumeration of bifidobacteria difficult. In order to develop optimum conditions for selective enumeration of bifidobacteria, we examined MIC of several antibiotics against various bifidobacteria and other lactic acid bacteria. The growth of L. acidophilus, L. bulgaricus and S. thermophilus were inhibited by lithium chloride at the concentration of less than 4 mg/ml, whereas growth inhibition of bifidobacteria occurred at concentrations over 6-10 mg/ml. Tetracycline and chloramphenicol were also found to selectively inhibit growth of other lactic acid bacteria at the concentration of 1-3 $\mu$g/ml. Addition of 6 mg/ml lithium chloride, 1 $\mu$g/ml, tetracycline or 3 $\mu$g/ml chloramphenicol to medium was found to be optimal for selective enumeration of bifidobacteria. By using these three inhibitory chemicals in the TPY medium, higher number of bifidobacteria were selectively isolated than with NPNL agar and LP agar.

• Journal of Ginseng Research
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• 제3권2호
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• pp.113-126
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• 1979

This study was undertaken to assess the effect of the Korean red ginseng extracts on the growth of lactic acid bacteria, such as Lac. acidophilus and Str. thermophilus. The results are summarized as follows: 1. The growth of all the lactic acid bacteria tested in this study was not influenced when the skim milk was added with the red ginseng extracts in concentration of less than 4.0%. But the growth was remarkably inhibited in the presence of 8.0% red ginseng extracts in skim milk. 2. Titratable acidity was more or less increased by addition of red ginseng extracts as compared with control except when the amount of 8.0% red ginseng extracts were added into skim milk. 3. No particular effect was observed in the growth of lactic acid bacteria in case of addition of saponins. But the remarkable inhibitory effect was observed in the skim milk with the amount of 1.2mg/ml the fractions extracted by ethyl ether from red ginseng extracts.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.680-683
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• 2000

고온성 박테리아인 Hydrogenobacter thermophilus가 생산하는 cytochrome c-552 유전자에 대한 primer를 제작하여 PCR을 통해 증폭한 후 E. coli에 cloning하였다. 또한 point mutagenesis를 통해 fusion protein을 만들기 위한 기초자료를 마련하였다. 앞으로 cytochrome c-552가 E. coli에서 mutant type으로 발현되기 위한 발현벡터의 개발과 이를 정제하는 기술을 개발하는 것이 필요할 것이다.

• 한국식품영양과학회지
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• 제30권3호
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• pp.439-443
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• 2001

The effect of fermentation of peanut milk with lactic acid bacteria on n-hexanal content was investigated. Changes in pH, titratable acidity and viable cell populations indicated that Streptococcus salivarius subsp. thermophilus was adapted better than Lactobacillus delbrueckii subsp. bulgaricus during fermentation. Analysis of headspace volatiles revealed that n-hexanal, which is one of the compounds responsible for undesirable green/beany flavor in peanut milk, completely disappeared as a result of fermentation. S. salivarius subsp. thermophilus was more effective than L. delbrueckii subsp,. bulgaricus in reducing the n-hexanal content. No significant difference was found in water sorption between fermented and unfermented peanut milk.

• Molecules and Cells
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• 제24권1호
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• pp.27-36
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• 2007

The hypothetical protein TTC0263 of Thermus thermophilus HB27 is a thermophilic tetratricopeptide repeat (TPR)-containing protein. In the present study, the TPR region (residues 26-230) was resolved at $2.5{\AA}$ with R-factors of $R/R_{free}$ = 23.6%/28.6% $R/R_{free}=23.6%/28.6%$. TTC0263 consists of 11 helices that form five TPR units. Uniquely, it contains one atypical "extended" TPR (eTPR) unit. This comprises extended helical residues near the loop region of TTC0263, such that the helical length of eTPR is longer than that of the canonical TPR sequence. In addition, the hybrid TPR domain of TTC0263 possesses oligomer-forming characteristics. TPR domains are generally involved in forming multi-subunit complexes by interacting with each other or with other subunit proteins. The dynamic structure of TTC0263 described here goes some way to explaining how TPR domains mediate the formation of multi-subunit complexes.

• 한국식품영양학회지
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• 제11권6호
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• pp.600-605
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• 1998

Present study was investigate to evaluate the aluminum absorption effect on lactic acid bacteria(Lactobacillus acidophilus ATTC 4356, Lactogacillus bulgaricus ATTC 11842, Lactobacillus casei IFO 3533, and Streptococcus thermophilus KCTC 2185 ; LAB) and Clostridium perfringens ATCC 3627 (CP) in artificial intestinal tract. Their growth rate, aluminum accumulation and cellular distribution was studied under anaerobic broth system. All of above microbes were inhibited by adding 10 to 100ppm of aluminum. The degree of aluminum in LAB (Lactobacillus acidophilus ATCC 4356, Lactobacillus bulgaricus ATCC 11842, Lactobacillus casei IFO 3533, and Streptococcus thermophilus KCTC 2185) was higher than of CP. The largest amount of aluminum was accumulated in Lactobacillus bulgaricus ATCC 11842. Aluminum accumulation in LAB was distributed in 49.1% at cell wall, 27.3% at plasma membrane, and 23.6% at cytoplasm, respectively. This study suggests that LAB might help to eliminate the ingested aluminum in intestinal tract.

• 한국식품영양학회지
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• 제26권1호
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• pp.146-149
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• 2013

This study was performed to identify the effect of lactic-fermentation of peanut milk on n-hexanal content. Changes in viable cell populations, pH and titratable acidity indicated that there was a synergistic interaction between Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus during fermentation. The analysis of headspace volatiles revealed that n-hexanal nearly disappeared due to fermentation. S. salivarius subsp. thermophilus was more effective than L. delbrueckii subsp. bulgaricus in reducing the n-hexanal content.

• 한국식품영양학회지
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• 제7권1호
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• pp.45-50
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• 1994

This study was carried out to Investigate the effects of Panax ginseng, Ganoderma lucidum extract and crude polysaccharide of G. lucidum on the growth of lactic acid bacteria. p. ginseng extract contained 60.7% carbohydrate and 27.5% protein, whereas G. lucidum contained 35.9% carbohydrate and 46.3% protein. The total sugar and protein content of crude polysaccharide of G. lucidum were 47.2% and 15.2%, respectively. Two amino acids(hg, Trp) were detected in p. ginseng extract and 11 amino acids (hg, Trp, Ua, Lys, Ser, etc.) in C. lucidum extract. By the addition of p. ginseng, 5. lucidum extract and crude polysaccharide, the cia. p. ginseng was more effective on the growth of 1. casei an: G. lucidum was more effective on that of S. thermophilus. The effect of free amino acids on the growth of tactic acid bacteria was also examined. Arginine and lysine stimulated the growth of L. casei, whereas Lysine, serine, arginine, and glutamic acid stimulated the growth of 5. thermophilus.