• 한국식품영양과학회지
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• 제29권1호
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• pp.35-40
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• 2000

The effect of levanheptaose produced by levanase from Streptomyces sp. 366L on principle intestinal microflora was investigated. The reaction product, levanheptaose, was used as a carbon source for various intestinal microflora. As a results, Bifidobacterium adolescentis, Lactobacillus acidophilus, and Eubacterium limosum grew effectively in the in vitro experiment, whereas Clostridium perfringens, E. coli, and Staphylococcus aureus did not. Therefore levanheptaose seems to promote selectively the growth of B. adolescentis and L. acidophilus. In the in vivo experiment, the effect of levanheptaose on the growth of intestinal microflora, $\beta$-fructosidase activity, pH, and butyrate concentration were examined in rats. Apparently, the number of fecal Bifidobacteria, the amount of butyrate, and $\beta$-fructosidase activity were increased, whereas total aerobes and pH were reduced in rats fed by levanheptaose diets, compared with those of control diets. We concluded that those effects may be beneficial in improving gastrointestinal health.

• 미생물학회지
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• 제35권2호
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• pp.153-157
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• 1999

Pseudomonas sp. K-52 유래의 levanase 에 의해 생산되는 levanoctaose 가 growth factor로서 각종 장내미생물에 미치는 영향을 조사하였다. In vitro 실험에서 0.5% levanoctaose를 탄소원으로 하여 glucose 일 경우와 상호 비교하여 분석한 결과 levanoctaose 는 Escherichia coli, Clostridium perfringens, Eubacterium limosum, Staphylococcus aureus 보다 Bifidobacterium adolescentis, Lactobacillius acidophilus, Bacteroid fragilis 등에 의해 효율적으로 이용되었다. 쥐를 이용한 in vivo 실험에서 탄소원의일부로 levanotaose를 제공한 경우, 장내 Bifidobacteria 수는 약 10배, butyrate 양은 2.3배, $\beta$-fructosidase 활성은 약 1.5배 증가하였다. 따라서 분리균주 Pseudomonas sp. K-2의 levanase로부터 생성되는 levanoctaose는 Bifidobacteria, Lactobacillus 와 같은 장내 유익균주에 선별적으로 이용되는 것이 확인되었다.

• 한국식품영양과학회지
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• 제27권3호
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• pp.441-447
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• 1998

A bacterial strain No. 43 was isolated from soil samples as a levan-assimiating microorganism producing an extracellular levanase and hydrolying levan to levanbiose. According to the taxonomic characteristics of its morphological and physiological properties, the strain was idenified as Pseudomonas sp. No. 43. The optimum culura medium was composed of 10g levan, 5g(NH4)2SO4, 3g NH4Cl, 3g polypepton, 1g K2HPO4, 0.5gMgSO4.7H2O, and 0.2g MnCl2.4H2O per liter. The cultivation for levanase was carried out in pH 7.0 at 4$0^{\circ}C$ for 28hr. The reaction product was a kind of oligosaccharide and it was purified by chilled ethanol precipitation and gel filtration for evalluation of degree of polymerization (DP). The purified product was determined as levanbiose of MW 342 and DP2 by HPLC and FAB-MS.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권6호
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• pp.582-586
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• 2005

In this Study, we have attempted to determine the effects of dietary fructose polymers (fructan), high molecular-weight ${\beta}-(2,6)-linked$ levan, and low-molecular-weight ${\beta}-(2,1)-linked$ inulin, on two intestinal enzymes $({\beta}-glucuronidase\;and\;{\beta}-glucosidase)$. As a preliminary experiment, when intestinal microflora were cultured in anaerobic media harboring levan or its oligosaccharides, bacterial cell growth was observed in the levanoligosaccharide-supplemented media, but not in the levan-supplemented media, indicating that levan's size is important for the utilization by intestinal bacteria of levan as an energy Source. In our animal study, the intake of a levan-rich diet was determined to significantly attenuate the activity of the harmful enzyme $({\beta}-glucuronidase$, but d id not affect the activity of ${\beta}-glucosidase$.

• 미생물학회지
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• 제34권1_2호
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• pp.37-42
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• 1998

토양으로부터 levan을 분해하여 단일종의 fructooligosaccharide를 생산하는 새로운 미생물을 분리 선별하여 본 연구의 공시균주로 선택하였다. Levanase 생산을 위한 최적 배지조성은 0.5% levan, 0.3% yeast extract 0.3% $NaNO_3$, 0.1% $K_2HPO_4$, 0.05% NaCl(pH 8.0)이었으며, 500ml용 shaking flask에 배지 50ml를 넣어 $30^{\circ}C$에서 54시간 배양시켰을 때 목적효소의 생산이 최대에 도달하였다. Levanase에 의해 생성되는 생성물은 단일종의 oligo당임이 확인되었으며 측쇄가 많은 levan으로부터는 소량의 측쇄구조를 가진 oligosaccharide로 추정되는 미지의 물질이 부산물로 생성되었다. 생성 oligo당을 순수하게 정제하여 HPLC 및 ESI-MASS로 중합도를 조사한 결과 DP가 7인 levanheptaose임이 판명되었다.