• Microbiology and Biotechnology Letters
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• v.20 no.4
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• pp.470-476
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• 1992

Upon lyophilization of Nocardia mediterranei, the effects of cryoprotectants, cell concentration and drying time on viability were examined, The data were treated by computer according to response surface analysis. As a result, the maximum value of presumed viability was 39.3% under the optimal conditions of 1l.6%(v/v) sucrose, $1.16{\times}10^{11}$(CFU/ml) cell concentration, and drying time for 6.18 hrs. We also used the starter cell of rehydrated solution after lyophilization in industrial production, obtained the fermentation pattern and the purity of rifamycin B which were the same with control (FVM) and it is possible for us to use N mediterranei as a starter cell after the storage of lyophilization for 18 months.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1976.10a
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• pp.187.3-187
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• 1976

건조 유산균 starter (Lyophillized lactic sarter) 제조 과정 중 동결건조에 의한 viability의 저하를 방지하는 방법의 하나로서 유산균을 농축 (concentrate) 시켰다. 유산균을 농축시키기에 앞서 cell의 농도를 높여줄 필요가 있었으므로 Cell의 증식에 영향을 미치는 요인으로 agitation 및 aeration을 채택하여 그것이 cell의 증식 및 lactic acid producing ability에 미치는 영향을 조사한 결과 다음과 같은 사실을 알 수 있었다.(중략)

• Korean Journal of Food Science and Technology
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• v.20 no.2
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• pp.140-147
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• 1988

The pysicochemical and bacteriological properties of yogurts made by single or mixed cultures of L. bulgaricus FRI025 and S. thermophilus CHI were investigated. L. bulgaricus FRI025 which was isolated from raw milk was selected as starter culture among 22 strains of lactic culture by measuring viscosity, flavor, growth and acid production ability. The acid production and number of viable cell were increased by using L. bulgaricus FRI025 and S. thermophilus CHI together in ratio of apporximately 1:1. The pH, titratable acidity, viable cell number and viscosity of yogurt were 4.08, 1.14%, $2.5{\times}10^{10}/ml$ and 2100 cp after 9 hours incubation at $40^{\circ}C$, respectively. The pH and viable cell number were decreased on the other hand titratable acidity and viscosity were increased after 7 days of storage at $4^{\circ}C$. The changes of quality did not show significantly after storage. The selected starter was much higher than commercial yogurt starter in the acid production and growth of starter. The yogurt nanufactured with selected starter was better than with commercial yogurt in sensory evalution such as taste, texture, flavor and overall acceptability.

• Microbiology and Biotechnology Letters
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• v.8 no.1
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• pp.19-25
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• 1980

Trials of investigating the effect of freezing and lyophilization, as the practical lactic starter preservation methods, on the viability and lactic acid producing activity of Lactobacillus bulgaricus NLS-4 have been carried out. After the treatments, both of viability and activity were decreased. However, when the initial cell cocentration was increared, the survival rate against freezing could be raised to 46% and the activity to 0.25% lactic acid whereas those against lyophilization were 22 ％ and 0.29% lactic acid, respectively. There were further increased maximally when the cell suspension was subjected to freezing and lyophilization after the addition of protective agents such as glycerol and the G. C. G. S. suspending medium.

• The Korean Journal of Food And Nutrition
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• v.17 no.1
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• pp.8-17
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• 2004

The effect of chlorella extract on the growth and acid production of yoghurt starter was investigated in order to prepare the yoghurt added with chlorella extract. The various levels of chlorella extract powder were added to skim milk medium and the medium was fermented by single or mixed culture of 4 types of lactic acid bacteria such as Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus casei, and Lactobacillus bulgaricus. The changes in acid production(pH, titratable acidity) and number of viable cells of the medium during fermentation in skim milk added with chlorella extract powder have determined. When chlorella extract powder was added to skim milk medium at the levels of 0.5%, 1.0%, 2.0%, and 3.0%, the addition of 0.5% chlorella extract powder with the single culture of Str. thermophilus, Lac. casei, and Lac. bulgaricus showed the highest number of viable cell counts after 9 hours incubation. And also all single cultures of the yoghurt starter produced the higher amounts of acid with the addition of 0.5% chlorella extract powder. When chlorella extract powder was added to the medium at the levels of 0.25%, 0.5%, 1.0%, and 2.0%, the addition of lower lever(0.25∼0.5%) of chlorella extract powder with the mixed culture of the lactic acid bacteria showed more the acidity of pH and the number of viable cell counts. Among the treatments tested, the addition of 0.25% chlorella extract powder with the mixed culture of Str. thermophilus and Lac. casei produced the highest number of viable cell counts after 12 hours incubation. Therefore it was suggested to manufacture the yoghurt with the addition of 0.25% chlorella extract powder and the inoculation of mixed culture of Str. thermophilus and Lac. casei for on the stimulation of growth of the yoghurt starter.

• Journal of the East Asian Society of Dietary Life
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• v.24 no.5
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• pp.641-645
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• 2014

This study was performed to investigate the possibility of using three commercial bifidobacteria as a starter for soybean paste fermentation. In order to determine susceptibility to inhibition by high concentrations of salt in soybean paste, cell growth of three strains in sterilized soybean paste was analyzed. Bifidobacterium breve KCTC 5081 was the most resistant to salt, whereas Bifidobacterium bifidum KCTC 5082 showed low cell viability. Conversion efficiencies from glycoside isoflavone to aglycon isoflavone in soybean paste ranged from 11.3~28.6%, with Bifidobacterium longum KCTC 5734 the best strain. Therefore, B. longum KCTC 5734 may be used as a starter for Cheonggukjang fermentation, which is low-salt fermented soybean paste.

• Food Science of Animal Resources
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• v.29 no.4
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• pp.437-444
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• 2009

${\gamma}-Aminobutyric$ acid (GABA) producing lactic acid bacteria, Lactobacillus acidophilus RMK567 was cultivated in 50 L of sterilized MRS broth using a fermenter at $40^{\circ}C$ for 24 h. The cell number was increased to $10.04{\pm}0.13$ Log CFU/mL with a growth rate constant (k) of 0.454 generation/h and a generation time (g) of 2.303 h after a lapse of a lag phase (L) of 5.16 h. A total of 487 g of cell paste with 40.5% moisture was harvested with viable cell number of 12.48 Log CFU/g cell paste. The cell pastes after preparation with glycerol, glucose, and polydextrose as cryo-protectants were lyophilized under a vacuum of 84 m torr. A total of 408 g of freeze dried (FD) cell powders were mixed with a commercial strain of Streptococcus thermophilus to prepare of three types FD starter cultures with the viable cell numbers of 12.42 (FDA-GY), 12.60 (FDBGG) and 12.91 (FDC-GP) Log CFU/g. During preservation the FD cultures at -$18^{\circ}C$, the cell viability of the FD starter cultures were rapidly dropped to below 3.24% of the day of storage. No significant difference was found in the cell viabilities among three types of FD starters cultures, but significant difference (p<0.01) was found in storage periods. Yoghurts fermented through FD starter culture of L. acidophilus RMK567 were determined to contain $155.16{\pm}8.53$ ppm, $243.82{\pm}4.27$ ppm, and $198.64{\pm}23.46$ ppm of GABA, respectively. This study shows that GABA production activity of L. acidophilus RMK567 is not affected during the freeze drying process and would be available for commercial production of yoghurt containing high GABA content.

• Journal of Dairy Science and Biotechnology
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• v.36 no.3
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• pp.178-185
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• 2018

Kefir, which originates in the Caucasian mountains, is a cultured milk beverage produced by a combination of acidic and alcoholic fermentation. Kefir products are commonly used as food vehicles to deliver health-promoting materials including kefran and lactic acid bacteria to consumers. The aim of this study was to develop a freeze-dried starter culture without yeast and assess the suitability of kefir-like dairy products for the growth of lactic acid bacteria and the acidification of milk. Pasteurized whole milk (SNF 8.5%) stored at $25^{\circ}C$ was aseptically inoculated with starter cultures (0.002% w/v); it was kept at $25^{\circ}C$ until the pH attained a value of 4.6. Ten grams of the kefir-like product sample was diluted with 90 mL of 0.15% peptone water diluent in a milk dilution bottle, followed by uniform mixing for 1 min. Viable cells of Lactobacillus species were enumerated on modified-MRS agar (pH 5.2), with incubation at $37^{\circ}C$ for 48 h. Viable cells of Lactococcus species were enumerated on M17-lactose agar, with incubation at $32^{\circ}C$ for 48 h. The pH attained a value of 4.6 after fermentation for 9 h 30 min (Starter 1), 9 h 45 min (Starter 2), and 12 h (Starter 3). The viable cell count of Lactobacillus sp. and Lactococcus sp. was initially $10^5{\sim}10^6CFU/g$; it increased significantly to $10^9CFU/g$ after 12 h of incubation. During the storage of the kefir-like products at $4^{\circ}C$ for 1 4 days, the total viable cell numbers were unchanged, but the pH decreased slightly. The consistency of the kefir products increased gradually during the storage. The organoleptic properties of the kefir products fermented using the new starter culture are more desirable than those of commercial kefir. These results suggest that the newly developed starter culture without yeast could be suitable for kefir fermentation.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.72-74
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• 2018

기존 자동차 및 트럭용 Jump Starter의 경우, 일반적인 자동차용 납축전지를 이용하여 사용하기 때문에 부피와 무게가 매우 커 휴대성이 어렵고, 고가의 제품군으로 형성되어 있어 일반 운전자들은 구입 및 사용하기 어려운 문제가 있다. 또한 리튬배터리를 이용한 Jump Starter의 경우, 부피는 줄었지만 원가가 매우 비싸고 주기적으로 충전을 하여 휴대해야하기 때문에 이용성에 불편함이 있고 실제 트럭이나 버스 같은 대용량 배터리는 Jump Starter가 구동을 하지 못하는 문제점이 있다. 본 논문은 자동차 및 트럭용 Jump Starter의 부피 및 원가를 최소화하면서 일반 운전자들도 휴대 가능한 편리성을 높이며, 대형트럭도 적용 가능한 건전지와 Super Capacitor를 이용한 초소형 저가형 Jump Starter 회로를 제안한다. 기존의 Jump Starter는 납축전지나 리튬전지를 사용하기 때문에, 전체적인 회로의 부피가 크고 무거우며 전체 제품의 원가가 증가하여 제품성이 떨어지는 단점이 있다. 또한 리튬전지를 사용하게 되면 주기적으로 충전을 해야 하기 때문에 소비자가 휴대 및 이용하기에 불편한 문제점도 있다. 반면 제안된 회로는 일반 소모용 건전지로도 Jump Starter 회로 구동이 가능하기 때문에, 운전자의 휴대성이 간편하고 언제 어디서든 소모용 건전지를 구매할 수 있기 때문에 운전자의 휴대성과 이용성이 매우 우수하다. 또한 순간적인 방전이 가능한 Super Capacitor를 이용하여 전체적인 회로의 부피 및 제품의 원가를 최소화 할수 있는 장점을 갖는다. 본 논문에서는 제안된 회로이 이론적인 특성을 분석하고 모의실험을 통해 확인하였으며, 실제 방전된 배터리 및 대형버스에 적용하여 실험을 통해 우수성을 검증하였다.

• Preventive Nutrition and Food Science
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• v.9 no.2
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• pp.138-143
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• 2004

Soybean curd residues (SCR) obtained from hot and cold manufacturing processes were fermented by indigenous microorganisms, Lactobacillus rhamnosus LS and Bacillus firmus NA-l for 15 h at 37$^{\circ}C$. The pH, acidity, viable cell counts, and tyrosine content were evaluated in samples with variations in sugar, starter and type of SCR. The raw Doowon SCR (D-SCR, cold-processed) fermented by indigenous microorganism had a 0.9% acidity and 6.7 ${\times}$ 10$^{7}$ CFU/g viable cell counts, compared with the 0.11 % acidity and 6.7 ${\times}$ 10$^{6}$ CFU/g viable cell counts of raw fermented Pulmuwon SCR (P-SCR, hot-processed). After fermentation of raw P-SCR with 1 % glucose and 1 % L. rhamnosus LS starter, the viable cell counts, tyrosine content and acidity were 4.7 ${\times}$ 10$^{8}$ CFU/g, 16.3 mg% and 0.9%, respectively. In addition, the raw P-SCR fermented with Bacillus firmus NA-l as co-starter had a 0.45% acidity, 2.4 ${\times}$ 10$^{8}$ CFU/g lactic acid bacteria, and 3.3 ${\times}$ 10$^{6}$ CFU/g Bacillus sp. In particular, the tyrosine content was increased 5 fold. The drying of fermented SCR was completed by hot-air drying (5$0^{\circ}C$) within 12 h; the dried P-SCR and D-SCR had 1.8 ${\times}$ 10$^{7}$ CFU/g and 5.3 ${\times}$ 10$^{6}$ CFU/g viable cell counts, respectively. The concentrate of methanol extract from fermented D-SCR inhibited the initial cell growth of E. coli, Staphylococcus aureus and Pseudomonas aeruginosa in liquid culture.