• 한국식품영양학회지
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• 제6권3호
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• pp.208-210
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• 1993

In order to know the influences of heat treatment of yoghurt on pH, $\beta$-galactosidase and viable cells, yoghurt sample was made by general method with Lactobacillus bulgaricus and Streptococcus thermophilus, and the changes in pH, $\beta$-galactosidase-activity and viable cell-count were determined during heating at 55$^{\circ}C$ and 7$0^{\circ}C$. The pH of yoghurt was not changed when the yoghurt was heated at 7$0^{\circ}C$, but at 55$^{\circ}C$ it decreased slightly. The stability of $\beta$-galactosidase was not affected markedly by heat treatment at 55$^{\circ}C$, but was rapidly inactivated at 7$0^{\circ}C$. The heat treatment of yoghurt at 55$^{\circ}C$ had the halb of viable cell in 1 hour, but the heat treatment at 7$0^{\circ}C$ had considerable effect on viable cell in 5 minutes.

• KSBB Journal
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• 제26권6호
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• pp.529-532
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• 2011

Whey based medium was optimized for the production of viable Lactobacillus crispatus KLB 46 isolated from the vagina of Korean women. Among the various nitrogen sources such as yeast extract, beef extract, and proteose peptone no. 3 supplemented to whey, beef extract showed the highest viable cell production. The addition of Tween 80 to the whey based medium increased viable cell concentration. As beef extract supplementation is not economically attractive, corn steep liquor was added as a supplementary nitrogen sources. When corn steep liquor was supplied with beef extract with the ratio 5 : 1, the viable cell count was $3.11{\times}10^9$ CFU/mL. Also, the addition of mineral salts containing sodium acetate (5 g/L), potassium phosphate dibasic (2 g/L), magnesium sulfate (0.1 g/L) and manganese sulfate (0.05 g/L) to the whey medium increased viable cell count further ($5.00{\times}10^9$ CFU/mL).

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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• pp.372-375
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• 2000

Lactobacillus cristatus KLB 46 isolated from Korean woman was grown on supplemented whey medium and medium compositions were optimized for maximum viable cell count. Among the nitrogen sources tested, beef extract yielded the highest viable cell number. When corn steep liquor was applied as an additional nitrogen source, the viable cell number was highest $(3.11{\times}10^9\;CFU/ml)$ in the medium containing 50g/ l corn steep liquor and 10g/ l beef extract. The highest viable cell $count(5.00{\times}10^9\;CFU/ml)$ was obtained from the supplemented whey medium that contains beef extract(10g/ l ), corn steep liquor(50g/ l ), tween 80(0.1%, v/v) and trace amounts of sodium acetate(5g/ l ), dipotassium phosphate(2g/ l ), magnesium sulfate(0.1g/ l ), and manganese sulfate (0.05g/ l ).

• Preventive Nutrition and Food Science
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• 제9권3호
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• pp.206-212
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• 2004

Prickly pear extract (PPE) was fermented by Lactobacillus rhamnosus LS at 3$0^{\circ}C$ for 2 days. To improve the physicochemical properties of fermented PPE, it was fortified with food polysaccharides (0.2 %) or seaweed calcium before lactic acid fermentation. The viable cell counts, flow behavior, titratable acidity and color stability of fermented PPE were evaluated during 4 weeks of cold storage. Addition of xanthan gum or glucomannan increased the apparent viscosity and acid production, viable cell counts and red color of PPE were also well maintained during the cold storage. However, fermenting PPE with gellan gum resulted in a decrease in relative absorbance, indicating lower color stability. In particular, PPE fortified with carrageenan or alginic acid showed reduced acid production and lower viable cell counts. Addition of seaweed calcium at a 0.1 % level had positive effects on color stability, and helped maintain viable cell counts of 4.1 ${\times}$ 10$^{9}$ CFU/mL. This study demonstrated that xanthan gum could be used as a good thickening agent and stabilizer for retaining viable cell counts and red color during the cold storage in PPE fermented by lactic acid bacteria.

• KSBB Journal
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• 제13권3호
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• pp.251-258
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• 1998

Scutellaria baicalensis. G. 식물 세포의 현탁 배양에서 세포의 성장과 flavonoid glycosides 생산에 관한 구조적 성장 모텔 을 제안하였다 제안된 모델식은 현탁 배양의 형광을 측정함으 써 결정될 수 있는 세포 생존도와 세포 활동도 등플 세포의 생리학적 변수로서 고려하였다. 제안된 모델식에서는 세포의 상태에 따라 세포블 크게 생존 세포와 비생존 세포로 나누고 생존 세포를 분화 가능한 생존 세포와 비분화 생존 세포로 나누어 각 각의 모델을 구성하였다. 이 중 생존 세포 중량은 광섬유 형광 센서로 측정한 상대 형광 세가로부터 결정될 수 있었다. Flavonoid 배당체의 생산 속도는 분화 가능한 생존 세포와 바 분화 생존 세포에 의해 지배되며, 배양액의 삼투압에 의한 서l포 팽창과 세포내 생성불절의 방출은 비생존 세포에 의해 이루어진다고 가정하였다. 종속변수는 가칠농도(포도당), 세포 중량(건조 세포중량과 생체중량), 대사산물농도(flavone glycosides), 활동도와 생존도플 포함한다 Scutellaria baicalensis. G. 식물 세포 의 푹라스크 배양으로부터 모델과 실험결과가 잘 일치함을 알 수 있었다. 제시된 모델은 세포의 성장, flavone glycosides 및 중간매개체 합성을 예측할 수 있다.

• Journal of Microbiology and Biotechnology
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• 제6권2호
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• pp.128-131
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• 1996

Lactobacillus acidophilus KFRI 233 (of human origin) exhibited a high tolerance to bile. The maximum cell yield was 6.6${\time}10^9 CFU$ per gram of whey in a 5.0% whey medium. Cell growth was improved with the addition of 0.5% thiotone and 0.25% calcium carbonate. Cell growth reached a maximum level of 5.4${\times}10^8$ CFU/ml at 20 h. Eighty-nine percent of the viable cells in the centrifuged concentrate survived freezing at $-70^{\circ}C$ and this frozen concentrate showed no reduction in the viable cell count after 30 days at $-70^{\circ}C$. Eight percent of the viable cells survived freeze-drying after the addition of 1 g/l sodium carbonate before harvesting by centrifuging and this freeze-dried concentrate showed only a slight reduction in the viable cell count after 30 days at $4^{\circ}C$.

• 한국미생물·생명공학회지
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• 제20권6호
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• pp.687-692
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• 1992

혼합배양중의 각 미생물의 생균수 측정은 순수배양보다 훨씬 복잡하다. 특히 두 균주의 크기가 비슷한 경우에는 사용할 수 있는 방법이 더 제한된다. 본 연구에서는 두 균의 크기가 비슷한 경우에도 적용될 수 있는 간단한 생균수 측정방법을 개발하였다. 미생물 배양액의 산소흡수속도(OUR)는 세포수에 비례하며 이때의 비례상수인 최대 비산소흡수속도( maximum specific OUR)를 알고 있으면 배양액의 OUR을 측정함으로써 간접적으로 생균수를 구할 수 있게된다. 혼합배양의 경우 산소흡수속도는 각 미생물의 호흡속도의 합이 되며, 각 미생물의 호흡속도가 서로 다르고 또한 온도의존성이 다르다면 호흡속도의 측정을 이용하여 각 생균수를 간접적으로 측정할 수 있다.

• Journal of Dairy Science and Biotechnology
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• 제41권4호
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• pp.157-162
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• 2023

In the field of microbiology, numerous types of bacteria live dormant to survive stresses such as pasteurization and antibiotics. Some bacteria become 'persisters' by inactivating their ribosomes, allowing them to 'sleep' through stress and revive when the stress has been removed. Under stress, some cells morph into hollow, lifeless structures known as 'cell shells.' In microbiology, these cells have been confused with viable cells in the 'viable but non-culturable cells' phenomenon. Therefore, this review addressed the concept that when revival occurs, the always-viable persister cells revive, instead of the dead cell husks.

• 한국축산식품학회지
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• 제21권2호
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• pp.133-141
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• 2001

Adherence of probiotic bacteria to intestinal epithelium is found to be the most principal characteristics among the various physiological functionality. This study was conducted to investigate the effect of bifidobacterial growth properties and condition on the Caco-2 cell adherence and to construct a basic data on adherence-related research. Among 20 strains of bifidobacteris tested, when measured by cell surface hydrophobicity(CSH) and cell agglutination(CA), Bifidobacterium bifidum ATCC29521, Bif. adolescentis K8, and Bif. infantis K9 were selected. Using these strains, variations of Caso-2 cell adherence depending upon experimental condition were analyzed. The results obtained are as follows : Even though Bif. bifidum ATCC29521, Bif. adolescentis K8, and Bif. infantis K9 reached more 85% cell surface hydrophobicity there was no significant difference in cell agglutination, when reached 31.54$\pm$0.54mg/ml. By direct count method for adherence, viable cell count of M3, K1, K2, K8, K9 and K10 reached more 100 counts per 100 Caco-2 cells. When Bif. bifidum ATCC29521, Bif. adolescentistis K8, and Bif. infantis K9 were used to compare the adherence depending upon viable cell counts, reaction time, and growth phase, the more viable cell count, and the more adhered cell counts, the less adherence percentage. In addition, there was no difference in adherence percentage of bifidobacteria when bifidobacteria was incubated from 1 to 8 hrs after Caco-2 cells already formed monolayer. Considering of the effect of growth phase of bifidobacteria on adherence variation, all strains showed the highest adherence during the early stage of stationary phase. In conclusion, adherence of bifidobacteria was affected by strain specificity, viable cell count, and growth activity.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권3호
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• pp.254-261
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• 2005

The over-expression of Bcl-2 has greatly improved the culture period, specific growth rate, and maximum viable cell density of NS0 cells culture under low serum condition. Further analysis of these data suggests that a saturation model of the Monod type can be used to represent the relationships of specific growth rate and initial serum concentration. The ${\mu}_{max}$ and $K_s$ for the Bcl-2 cell line is $0.927day^{-1}\;and\;0.947\%(v/v)$ respectively, which are $21\%$ greate and $7\%$ lower respectively than its control counterpart. Study on the amino acid supplementation revealed that Bcl-2 cell lines possess greater improvement in the specific growth rate and maximum viable cell density compared to the control cell lines. A further increase in the amino acid supplementation has resulted a $17\%$ decrease in specific growth rate and no improvement in maximum viable cell density in the control culture. However, the Bcl-2 cell line exhibited a better growth characteristic in this culture condition compared to that of control cell lines. The higher specific growth rate and maximum viable cell density of the Bcl-2 cell line in medium fortified with serum and MEM EM suggested a more efficient nutrient metabolism compared to that in the control cell line. The low serum and amino acid utilisation rate and the higher cell yield may prove to be important in the development of serum/protein free culture.