• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1986.12a
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• pp.532.1-532
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• 1986

유산균이 생성하는 polysaccharide 에 관한 연구의 일환으로서 L. casei YIT 9018 SKD-0007, L. bulgaricus SKD-0003, sir. faecalis SKD-1007, str. thermophilus SKD- 1005, str. thermophilus 510 SKD-1006등을 탈지유에 배양하면서 polysaccharide 생성에 의한 배양액의 점도 변화를 검토하였다. 이러한 다당류가 Antitumor로서의 활성과 제암효과를 가지며 인체내의 생리효과를 고양시킨다고 보고되어 있는바 다당류가 최대로 생성되는 조건을 찾는 것을 본 실험의 목적으로 하였다. 다당류의 생성을 측정하는 방법으로서 배지로는 10% 환원탈지유와 12% 환원전지유를 선택하였으며 Brookfield Viscometer를 사용하여 배양액의 점도를 경시적으로 측정하였다. 시험균 중에서 str. thermophilus 510 SKD-1006이 가장 높은 점도를 나타내었는데 41$^{\circ}C$ 배양 5일째에 5000 cps였고 다른균에 비해서 1000cps이상 높았다. 접종량이 증가할수록 점도도 증가하였으며 14%이상의 탈지유 농도에서는 7000cps를 나타냈다. 탈지유와 전지유 배양액 모두 의가소성 유체의 유동 양식을 나타내었는데 12% 환원전지유 배양액은 최대점도값이 2500 cps에 불과하였으며 배양 2일째에 최대점도 값에 도달하여 그 이후로 급격한 감소현상을 보였다.

• Food Science of Animal Resources
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• v.25 no.1
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• pp.84-91
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• 2005

We investigated fermentation characteristics and the amount of exopolysaccharide (EPS) produced, and the correlation between EPS and rheological properties in stirred yogurt fermented with Streptococcus thermophilus St-Body 1. The changes of pH and lactic acid concentrations of yogurt showed different patterns according to fermentation temperatures. About 20 to 40% of lactose was utilized during 6 hrs incubation. The higher number of lactic acid bacteria was obtained at 31℃ incubation temperature rather than other incubation temperatures. The higher amount of EPS was produced at 12 hr or 24 hr rather than other incubation period at the same fermentation temperatures. The viscosity continuously increased during the fermentation period, however the syneresis of yogurt was shown the lowest value at 37℃ for 30 hrs incubation. In physical properties, the hardness and adhesiveness increased continuously with decreasing cohesiveness and elasticity as incubation process was extended. The stirred yogurt fermented with S. thermophilus St-Body 1 at 37℃ for 24 hr resulted in the highest score at each sensory evaluation category.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.12
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• pp.1811-1814
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• 2009

The effect of fermentation with mixed cultures of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus on the microbiological characteristics of oat extract was investigated. Changes in pH, titratable acidity and viable cell populations indicated that growth was better in mixed cultures of L. delbrueckii subsp. bulgaricus and S. salivarius subsp. thermophilus. Growth of S. salivarius subsp. thermophilus in oat extract was more rapid than growth of L. delbrueckii subsp. bulgaricus. Cooperative interaction between two cultures during fermentation of oat extract as in yogurt from cow's milk was observed, but the intensity was relatively weak.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.687-700
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• 2004

This experiment was carried out to examine the fennentation properties of yogurts with or without Lyeii fructus, Lyeii folium and Lyeii cortex extract as additives at concentrations of 1.0%. The effects on promoting the fermentation by Lycii fructus, Lycii folium and Lycii cortex additives were higher and pH was below 4.06 when Streptococcus salivarius ssp. thermophilus and Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus cosei, and Lactobacillus acidophilus, Bifidobacterium longum and Streptococcus salivarius ssp. thermophilus were used. The acid production was higher when S. salivarius ssp. thermophilus and L. delbrueckii ssp. bulgaricw were used. The average lactic acid bacteria counts was 2.62 ${\times}$ $10^9$ cfu/ml in the yogurt added with Lycii fructus extract and fermentation with S. salivarius ssp. thermophilus and L. delbrueckii ssp. bulgaricw. The lactose hydrolysis ratio was higher in the milk added with Lycii fructus extract(36.11%), Lycii folium extract(37.76%) and Lycii cortex extract(32.70%) when S. salivarius ssp. thermophilus and L. delbrueckii ssp. bulgaricus were used. The isobutylic acid concentration was(34.39 to 37.72 mM) with S. salivarius ssp. thermophilus and L. delbrueckii ssp. bulgaricus. The viscosity of yogurt was 1,615 to 2,030 cP in yogurts added with skim milk and L. acidophilus; B. longum and S. salivarius ssp. thermophilus were used. The sensory scores of colors, tastes and overall acceptability of yogurt with Lycii cortex extract were shown 3.34 to 3.77 when fermented by L. cosei, L. acidophilus, B. longum and S. salivarius ssp. thermophilus. The cholesterol reducing effects were 17.38${\sim}$32.08% in all the yogurts and especially, greater effect(25.75 to 32.08%) for yogurts fermented with L. acidophilus KCTC3150 and L. salivarius subsp. salivarius CNU27. The inhibitory effects on the pathogenic bacteria by lactic acid bacteria added with Lycii fructus, Lycii folium and Lyeii cortex lower on S. typhimurium M-15, but higher on E. coli KCTC1021 and L. monocytogenes.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1978.04a
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• pp.96.4-96
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• 1978

발효유 제조에 있어 skim milk 대체원료로 soy-milk 및 defatted soymilk를 사용하여 명종유산균 (S. thermphilus, L. acidophilus, L. bulgaricus, S. thermophilus＋L. acidophilus, S. thermophilus＋L. bulgaricus, L. acidophilus＋L. bulgaricus) 의 증식 조건을 조사한 결과 soymilk의 균수는 skim milk와 defatted soy milk에 비하여 별 차이가 없었으나 적정산도는 현저히 낮았다. 또한, soymilk 및 defatted soy milk에 2％ lactose 첨가시 유산균 증식이 양호하였다.

• KSBB Journal
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• v.6 no.4
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• pp.413-424
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• 1991

The optimal condition for manufacturing the yoghurt by using B. bifidum and L. acidophilus was studied. Optimal growth condition of B. bifidum and fermentation effects of B. bifidum, L. acidophilus and Str. thermophilus in mixed culture were investigated separately. Fermentation conditions of B. bifidum were optimized in 12% reconstitued skim milk. The addition of BIOS 2000 to 12% skimmilk was effective on the growth and acid production of B. bifidum. There was asymbiosis among B. bifidum, L. acidophilus and Str. thermophilus in mixed culture which resulted in higher viable cell numbers and acid production. The optimum production of yoghurt was achieved by incubation at $37^{\circ}C$ for 8 hours with 5% mixed starter culture (B. bifidum+L.acidophilus+Str. thermophilus). In this case the effective ratio of B. bifidum: L. acidophilus: Str. thermophilus was 2:1:1 on both acid production and viable cell counts.

• Journal of Nutrition and Health
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• v.14 no.4
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• pp.175-181
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• 1981

This study was carried out to investigate the feasibility of production of soy yogurt, which is inexpensive and high protein product with an acceptable flavor, from soy milk using lactic acid bacteria. Utilization of various carbohydrates by Lactobacillus acidophilus, Streptococcus thermophilus and Lactobacillus bulgaricus was stuied. Sucrose, the major carbohydrate in soymilk, was fermented by L. acidophilus and S. thermophilus. None of the testing microorganisms was able to ferment melibiose and raffinose. Growth of lactic acid bacteria in soymilk was examined every 4 hour. L. acidophilus exhibited the highest growth rate during the early stage. After 16 hours of incubation, however, all the cultures with the exception of L. bulgaricus grew at nearly equal rates. Microscopic examination of mixed cultures showed that the presence of S. thermophilus was much more pronounced than that of L. bulgaricus. All the cultures with the exception of L. bulgaricus formed acid rapidly during 16 hours of incubation, bringing the titratable acidity to 0.6% and pH to 4.3, which was sufficient to cause coagulation of soymilk. L. bulgaricus produced acid to a much lesser extent and caused coagulation of soymitk after 30 hours at earliest. Three kinds of yogurts were prepared from 100% soymilk, 100% milk and 50% soy-50% milk combination by S. thermophilus and were evaluated by taste panel. Soy yogurt received a significantly lower mean odor score than milk yogurt. Soy yogurt had custardlike texture, while milk yogurt was syrupy. However the scores for texture as well as those for color and flavor did not differ significantly among the treatment. The mean total scores for yogurts were not significantly different and were equivalent to ratings between good and high fair.

• Journal of Oral Medicine and Pain
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• v.34 no.1
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• pp.23-37
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• 2009

The antibacterial effect of phytoncide on Porphyromonas gingivalis, which is the main causative agent of periodontal disease and halitosis, has been reported. However, little is known about its effect on normal oral microflora. The present study was performed to observe the effect of phytoncide on oral normal microflora and the inhibitory effect of surviving resident oral bacteria on P. gingivalis. In this study, saliva from each of 20 healthy subjects was treated with 1% phytoncide from Japanese Hinoki (Chamaecyparis obtusa Sieb. et Zucc.). Surviving salivary bacteria were isolated on blood agar plates and identified by 16S rDNA sequencing. In order to select inhibitory isolates against P. gingivalis, the isolates from the phytoncide-treated saliva were cultured with P. gingivalis. The results were as follows: 1. In general, the number of bacteria in saliva from periodontally healthy subjects was decreased when the saliva was treated with 1% phytoncide. 2. The majority of the salivary bacteria surviving the treatment of phytoncide were S. thermophilus (53%). 3. Most of the surviving salivary bacteria (72.5%) inhibit the growth of P. gingivalis A7A1-28 and P. gingivalis W83 on blood agar plates. 4. Among the surviving S. thermophilus, 85.8% of them were observed to inhibit P. gingivalis strains and 75.8% of the surviving S. sanguinis were inhibitory. Taken together, oral resident bacteria surviving phytoncide, which has been shown to inhibit P. gingivalis, may exert an additional inhibitory activity against the periodontopathic bacterium. Therefore, phytoncide can be used for preventing and ceasing the progress of periodontal disease and halitosis, and thus is expect to promote oral health.

• Microbiology and Biotechnology Letters
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• v.30 no.2
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• pp.151-156
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• 2002

This study was performed to obtain the thermostable $\beta$-glycosidase producing bacteria from hot spring of volcanic area at Atagawa in Japan. KNOUC 202 was selected because it showed thermostable $\beta$-glycosidase activity in sodium phosphate buffer(pH 6.8) at $70^{\circ}C$ for 4h, and it was identified. The strain was aerobic, asporogenic bacilli, immobile, gram negative, catalase positive, oxidase positive, and pigment-producing. Optimum growth was at $70~72^{\circ}C$, pH 7.0~7.2, and it could grow in the presence of 3% NaCl. The main fatty acids in cell were iso-15:0 and iso-l7:0. 16S rRNA sequence of KNOUC 202 showed 99.9% similarity with that of Thermus thermophilus ATCC 27634(HB8). Based on morphological, physiological, biochemical characteristics, cellular fatty acids profile and 16S rRNA sequence analysis, KNOUC 202 was identified as Thermus thermophilus.

• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.101-104
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• 1995

We isolated sixty lactic acid bacteria(LAB) from lactic fermented products. Among 60 isolates of LAB, 30 isolates were identified as Lactobacillus casei ssp.(5 strains), Lactobacillus acidophilus(2 strains), Lactobacillus delbrueckii ssp. bulgaricus(6 strains), Lactobacillus plantarum(4 strains), Streptococcus salivarius ssp. thermophilus(11 strains), and Streptococcus faecalis(2 strains). The acid tolerance and bile resistance of 30 LAB were determined. Because the acid tolerance was affected by the initial cell concentrations, the analysis of covariance could be used to remove the effect of initial cells on acid tolerance when testing for differences in acid tolerance among six species. Viability of LAB under acidic condition, pH 3 for 2 hours at $37^{\circ}C$, was significantly different among the species. L. casei and L. acidophilus strains showed great viability, but L. bulgaricus and S. thermophilus strains were very weak in acid tolerance.