• Asian-Australasian Journal of Animal Sciences
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• 제18권6호
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• pp.807-811
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• 2005

This experiment examined the characteristics of fermented juice of epiphytic lactic acid bacteria (FJLB) prepared by the addition of glucose, sucrose and molasses as a fermentation substrate. The effect of FJLB on the fermentative quality and changes in chemical composition during fermentation of guineagrass silage were also investigated. The pH value of the silages treated with FJLB rapidly decreased, and reached to the lowest value within 7 days of start of fermentation, as compared to the control. The number of lactic acid bacteria (LAB) in the treated silages increased for the first 3 days, thereafter the number of LAB declined gradually up to the end of the experiment. Silages treated with FJLB had larger populations of LAB than the control. Ammonia-nitrogen production increased throughout the ensiling period, which in the control and no-sugar added FJLB silages were higher than the other treated silages. Lactic acid levels varied with the time of ensiling and among the silage treatments. For any sugar FJLB treated silages, the lactic acid increased initially, and then slightly reduced to less than 50 g/kg of dry matter until 49 days after ensiling, except the silage treated with glucose added FJLB. Nevertheless, lactic acid content of the control decreased constantly from the beginning of ensiling and was not found after 35 days. Moreover, acetic acid content increased throughout the ensiling period. All the FJLB treated silages had significantly (p<0.05) lower pH and ammonia-nitrogen content, while significantly (p<0.05) higher lactic acid content and V-score value compared with the control. This study confirmed that the applying of FJLB with any sugar substrate improved fermentative quality of silage.

• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2418-2422
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• 2011

The enantiomeric separation of lactic acid for its absolute configuration has become important task for understanding its biological origin and metabolic process involved in the formation of lactic acid. It involves the conversion of enantiomers as diastereomeric O-pentafluoropropionylated (S)-(+)-3-methyl-2-butyl ester and the direct separation by gas chromatography-mass spectrometry on a achiral capillary column. The (R)- and (S)-lactic acids were completely separated with a high resolution of 1.9. The newly developed method showed good linearity (r ${\geq}$ 0.999), precision (% relative standard deviation = 3.4-6.2), and accuracy (% relative error = -7.7-1.4) with the detection limit of 0.011 ${\mu}g/mL$. When the method was applied to determine the absolute configuration of lactic acid in Lactobacillus delbrueckii subsp. lactis 304 (LAB 304), the composition (%) of (R)-lactic acid in the cell pellet and in the culture medium were $89.0{\pm}0.1$ and $78.2{\pm}0.4$, respectively. Thus, it was verified that the present method is useful for the identification and composition test of lactic enantiomers in microorganisms.

• KSBB Journal
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• 제17권6호
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• pp.566-570
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• 2002

Lactococcus lactis IO-1를 이용하여 xylose로부터 젖산발효를 수행한 결과 기질농도가 50 g/L에서 100 g/L로 증가됨에 따라 생육저해 및 생산성감소가 일어났다. 따라서 이온교환수지(Amberlite IRA-400, 250 g)를 이용하여 젖산을 발효 중에 제거함으로 최종산물저해를 완화시킬 수 있는 추출발효를 수행하였다. 초기 xylose 100 g/L에서 발효조내 젖산농도 20 g/L 에서 추출발효를 시작한 결과 기질을 거의 모두 소비하여 총53.6 g/L의 젖산을 생산하였으며 1.6 g/L·h의 생산성을 나타냈다. 이는 일반적인 회분발효에 비해 약 1.8배 향상된 결과로써 향후 수지에 젖간의 흡착을 저해하는 문제점을 개선함으로써 이온교환수지의 젖산 흡착량을 늘릴 수 있는 방안을 모색한다면 지금 보다 더 나은 생산성을 나타낼 것으로 사료된다.

• 약학회지
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• 제49권6호
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• pp.459-464
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• 2005

The immune reinforcement of the probiotic lactic acid bacteria Lactobacillus acidophilus, Streptococcus thermophilus and Bifidobacterium bifidum was studied in RAW 264.7 cell line treated with diluted solution (dilution to $2^{5}$) of the supernatnats of lactic acid bacteria. RAW 264.7 cell line was used as a macrophage model to assess the effects of lactic acid bacteria on the production of nitric oxide (NO) and cytokine tumor necrosis factor (TNF)-$\alpha$ and cell morphological changes. The production of NO and TNF-$\alpha$ were largely affected by lactic acid bacteria in dose-dependent manner in 24 or 48 hr cultures and cell morphological changes were also largely affected by lactic acid bacteria. Especially Bifidobacterium bifidum differentially stimulated the production of NO and TNF-$\alpha$. NO production was increased by Bifidobacterium bifidum 25 $\mu$l/ml more than LPS (20 ng/ml) control, and TW-$\alpha$ by Bifidobacterium bifidum 6.25 $\mu$l/ml more than LPS (10 ng/ml) control. The in vitro approaches employed here should be useful in further characterization of the effects of lactic acid bacteria on systemic immunity.

• International Journal of Advanced Culture Technology
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• 제3권2호
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• pp.100-109
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• 2015

Environmental problems from petroleum-based plastic wastes have been rapidly increasing in recent years. The alternative solution is focus on the development of environmental friendly plastic derived from renewable resource. Poly(lactic acid) (PLA) is a biodegradable polymer synthesized from biomass having potential to replace the petroleum-based non-degradable polymers utilizations. PLA can be synthesized by two methods: (1) ring-opening of lactide intermediate and (2) direct polycondensation of lactic acid processes. The latter process has advantages on high yields and high purity of polymer products, materials handling and ease of process treatments. The polymerization process of PLA synthesis has been widely studied in a laboratory scale. However, the mass scale production using direct polycondensation of lactic acid has not been reported. We have investigated the kinetics and scale-up process of direct polycondensation method to produce PLA in a pilot scale. The order of reaction is 2 and activation energy of lactic acid to lactic acid oligomers is 61.58 kJ/mol. The pre-polymer was further polymerized in a solid state polymerization (SSP) process. The synthesized PLA from both the laboratory and pilot scales show the comparable properties such as melting temperature and molecular weight. The appearance of synthesized PLA is yellow-white solid powder.

• 한국식품과학회지
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• 제17권5호
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• pp.361-370
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• 1985

수분, 대두유, Na-caseinate, 분리대두단백, 옥수수 전분, 젖산및 disodium phosphate를 주 원료로 하여 imitation치즈의 조직감 특성 견고성, 부착성, 탄력성 및 녹는 성질을 반응표면분석을 통하여 살펴본 결과 imitation치즈의 조직감에는 각 원료가 1차적 영향뿐 아니라 2차적인 영향과 원료 서로간의 교호작용의 영향도 매우 큰 것으로 관찰되었다. 특히 견고성에는 대두유와 Na-caseinate가 1차적으로 큰 영향을 미쳤고 수분과 대두유, 옥수수 전분과 젖산/인산염과의 교호작용 영향도 컸으며 부착성과 탄력성에는 젖산/ 인산염과 Na-seinate가 큰 영향을 미쳤으며 녹는 성질에서 또 Na-caseinate와 젖산과의 모든 교호작용함이 높은 유의수준을 보이므로 전체적으로 imitation치즈의 조직감 특성에는 Na-caseinate와 젖산/인산염의 영향이 매우 큰 것으로 나타났다. 또한 반응표면방법을 이용하므로 6가지 원료가 조직감 특성에 미치는 영향을 수학적으로 간단히 살펴볼 수 있었으며 동시에 등고선 그림을 통하여 각 조직감 특성에 두가지 원료가 서로 미치는 경향을 쉽게 관찰할 수 있었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2009년도 춘계학술대회 논문집
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• pp.769-770
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• 2009

• Food Science and Biotechnology
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• 제14권4호
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• pp.547-550
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• 2005

Fourteen out of 87 strains of lactic acid bacteria isolated tram Kimchi were found to be resistant against the action of artificial gastric and bile juices. In particular, lactobacilli KM 3, 7, 28, and 37 showed strong resistance and their viable cell counts at the initial stage remained the same even after 3 hours of cultivation in an artificial gastric juice. However, the survival rates of KM 14, 28, and 64 were found to be significantly enhanced in artificial bile juice. Based on the paper disc method, it was evident that isolated lactic acid bacteria showed antibacterial effect against Listeria monocytogenes, Escherichia coli, Bacillus subtilis, Staphylococcus aureus, Vibrio vulnificus, and Salmonella typhimurium. The isolated lactic acid bacteria were identified as Lactobacillus plantarum and Leuconostoc mesenteroides.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.259-262
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• 2003

In this study, batch production of lactic acid from cheap law material such as barley, wheat, and corn, was tried to lower the total production cost of lactic acid. Although no nutrients were supplemented, lactic acid productivities were achieved up to 0.88 $g/(L{\cdot}hr)$ from barley, wheat and com enzymatic hydrolysate. By adding corn steep liquor to com and wheat hydrolysate media, realtively high lactic acid $productivities(4.14\;g/(L{\cdot}hr))$ were obtained.

• KSBB Journal
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• 제25권4호
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• pp.311-318
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• 2010

Lactic acid bacteria display a relatively simple metabolism wherein the sugar is converted mainly to lactic acid. The extensive knowledge of metabolic pathways and the increasing information of the genes involved allows for the rerouting of natural metabolic pathways by genetic and physiological engineering. In this contribution, the lactic acid bacteria as an efficient cell factory for different (food) ingredients will be presented. The emphasis will be on some successful examples of metabolic engineering and on the physiology of these bacteria, which makes them so suitable as a cell factory.