• KSBB Journal
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• 제18권2호
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• pp.127-132
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• 2003

Alcohol류를 배양액 속에 첨가하면 배양 중에 생성되는 BC가 엉기는 현상이 나타났다. 생성된 BC의 엉김은 생산배지로부터의 cellulose의 분리회수를 손쉽게 할 수 있는 장점이 있다. 이 중에서 ethanol을 사용하는 경우에는 BC의 생산성과 미생물의 성장속도가 증가하였다. Ethanol 이외의 alcohol류는 BC의 엉김현상에는 효과가 있었으나 그 독성으로 인하여 미생물의 성장과 BC의 생산성을 감소시켰다. Ethanol과 다른 alcohol 모두 BC의 엉김효과는 있으나 ethanol만 진탕배양에서 $\textrm{Cel}^{-}$균주의 출현 방지에 효과가 있었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제7권5호
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• pp.289-294
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• 2002

Cellulose production by Acetobacter pasteurianus was investigated in static culture using four bioreactors with silicone rubber membrane submerged in the medium. The shape of the membrane was flat sheet, flat sack, tube and cylindrical balloon. Production rate of cellulose as well as its yield on consumed glucose by the bacteria grown on the flat type membranes was approximately ten-fold greater than those on the non-flat ones in spite of the same membrane thickness. The membrane reactor using flat sacks of silicone rubber membrane as support of bacterial pellicle can supply greater ratio of surface to volume than a conventional liquid surface culture and is promising for industrial production of bacterial cellulose in large scale.

• 미생물학회지
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• 제28권4호
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• pp.318-323
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• 1990

The bacterial secondary production was measured at 6 sites of Lake Soyang in October, 1989 by $^{3}$H-thymidine incorporation rate. Verfication for the method of bacterial secondary production measurement showed that $^{3}$H-thymidine incorporated into DNA, RNA and protein by average percentage of 38.45, 42.27 and 20.07%, respectively. THe more increased incoporated $^{3}$H-thymidine, the more increasde DNA fraction, but protein fraction was generally low. Incorporation of rate of /usp 3/H-thymidine. $^{3}$H-leucine into protein correlated with protein fraction of incorporated $^{3}$H-thymidine. Conversion factors were calculated as follows; $1.83*10 ^{20}$ cells/moles of thymidine incorporated/hr and 1.69*10$^{22}$ cells/moles of leucine incorporated/hr.

• 한국식품위생안전성학회지
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• 제11권4호
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• pp.227-234
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• 1996

This study was designed to characterize endotoxin-induced prostaglandin production in primary cultured rat vascular smooth muscle cells (VSMC). The time course for prostaglandin synthesis in lipopolysaccharide (LPS)-stimulated VSMC showed that the maximum production was reached in 12 hours. LPS induced prostaglandin H2 synthase (PGHS) activity in VSMC and the time course profile in the changes of PGHS activity paralleled that of total prostaglandin production. Differential treatment showed that 4 hours' exposure to LPS was enough for the maximum effect on the prostaglandin production and this effect was completely inhibited by the co-treatment of actinomycin D, a transcription inhibitor. These results suggest that LPS effect might be determined within 4 hours. Actinomycin D increased PGHS activity without affecting prostaglandin production if added 4 hours after LPS treatment. On the other hand, cyclogeximide, a translation inhibitor, augmented LPS-induced prostaglandin production if treated during first four hours, but it inhibited LPS-induced PGHS activity regardless of treatment schedule. These results suggest the existence of multiple regulating mechanisms in the LPS-induced prostaglandin synthesis.

• 미생물과산업
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• 제12권1호
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• pp.15-22
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• 1986

Chemical production by anaerobic bacterial fermentations was an important microbiological topic in the past due to both fundamental and applied aspects related to acetone-butanol production prior to its replacement by chemical synthetic routes from petroleum. Presently, the depletion and price-escalation of petroleum has regenerated a great interest in the potential of anaerobic bacteria to transform the renewable resouces such as biomass and wastes into chemical feed-stocks and fuels.

• KSBB Journal
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• 제18권2호
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• pp.94-99
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• 2003

Gluconacetobacter hansenii PJK의 경우 배지 조성 중 탄소원보다는 질소원 및 acetic acid가 BC 생산에 더 많은 영향을 미쳤다. 또한 BC 생산능은 pH 4.1-6.0 범위에서 배지의 초기 pH 영향을 거의 받지 않았으며 BC에 둘러싸인 균주보다 배양 상등액에 존재하는 균주의 BC 생산능이 더 우수하였다. G. hansenii PJK의 BC 생산은 fructose metabolism이 아닌 glucose metabolism으로 이루어지며 배지 성분 중 fructose와 lactate는 Cel$^{-}$ mutant의 발생 및 성장을 촉진시켰으며 TCA cycle에 위치하는 succinate의 첨가는 BC 생산에 거의 영향을 미치지 않았다.

• 미생물학회지
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• 제27권2호
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• pp.130-138
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• 1989

소양호에서 측정된 세균 체적, 세균 생물량 및 세균 생산량 등의 미생물학적인 요인의 변화에 미치는 물리화학적 환경요인의 영향을 통계학적 방법으로 분석을 하였다. 상관관계 분석과 중회귀 분석 결과 수온은 대부분의 미생물학적 요인에 폭넓은 영향을 미침을 알 수 있었다. 총 세균수, 세균 체적, 세균 생물 량 및 saprophyte 수외 변화는 엽록소 a와 pheophytin a의 존재와 높은 상관관계를, $^{3}H$-thymidine incorporation rate에 의해 측정된 세균 생산량은 seston의 농도에 큰 영향을 받는 것으로 분석되었다. 소양호 수중생태계에서의 세균 체적 및 세균 생물량의 미생물학적 요인은 미생물 군집에게 탄소와 에너지원으로 작용하는 유기물질의 제공원인 식물성 플랑크톤의 분포와 seston의 농도에 의해 조절되고 있음을 시사하여 준다.

• 한국환경과학회지
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• 제10권2호
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• pp.105-111
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• 2001

Improvement of water quality and Investigation of bacterial characteristics have been conducted in a pilot plant using biological activated carbon (BAC) in water treatment process at the downstream of the Nakdong River. Most of water control parameters were highly improved after passing through BAC. Approximately 54% of dissolved organic carbon was removed in coal-based BAC process. Bacterial biomass and bacterial production appeared $9.8{\times}10^8 CFU/g and 7.1mg-C/m^3$.hr in coal-based BAC, respectively. Predominant bacteria species grown in BAC were identified as Pseudomonas, Flavobacterium, Alcaligenes, Acinetobacter and Aeromonas species. Particularly Pseudomonas vesicularis was dominant in both coal-based and coconut-based BACs, while Pseudomonas cepacia was dominant in wood-based BAC.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권1호
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• pp.1-8
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• 2005

Bacterial cellulose (BC), which is produced by some bacteria, has unique structural, functional, physical and chemical properties. Thus, the mass production of BC for industrial application has recently attracted considerable attention. To enhance BC production, two aspects have been considered, namely, the engineering and genetic viewpoints. The former includes the reactor design, nutrient selection, process control and optimization; and the latter the cloning of the BC synthesis gene, and the genetic modification of the speculated genes for higher BC production. In this review, recent advances in BC production from the two viewpoints mentioned above are described, mainly using the bacterium Gluconacetobacter xylinus.

• Journal of Microbiology and Biotechnology
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• 제29권4호
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• pp.617-624
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• 2019

Bacterial nanocellulose (BNC) which is generally synthesized by several species of bacteria has a wide variety of industrial uses, particularly in the food and material industries. However, the low levels of BNC production during the fermentation process should be overcome to reduce its production cost. Therefore, in this study, we screened and identified a new cellulose-producing bacterium, optimized production of the cellulose, and investigated the morphological properties of the cellulosic materials. Out of 147 bacterial isolates from ripened fruits and traditional vinegars, strain SFCB22-18 showed the highest capacity for BNC production and was identified as Komagataeibacter sp. based on 16S rRNA sequence analysis. During 6-week fermentation of the strain using an optimized medium containing 3.0% glucose, 2.5% yeast extract, 0.24% acetic acid, 0.27% $Na_2HPO_4$, and 0.5% ethanol at $30^{\circ}C$, about 5 g/l of cellulosic material was produced. Both imaging and IR analysis proved that the produced cellulose would be nanoscale bacterial cellulose.