• 한국미생물·생명공학회지
• /
• 제23권5호
• /
• pp.593-598
• /
• 1995

The cultural conditions of Bullera singularis were optimized for the efficient production of galactooligosaccharide (GOS), Optimum temperature was 25$\circ$C, pH was 6.0, inoculum size was over 5% (v/v), initial lactose concentration was over 5% (w/v). The GOS production increased with microbial growth. Maximum amount of 72% (w/w) GOS was obtained from the optimized medium (5% lactose and 0.75% yeast extract) in 70 hours. Seven types of GOS (3 of dimer, 2 of trimer, 1 of tetramer, and 1 of pentamer) were identified by two-dimensional TLC. A new mechanism of GOS production is proposed based on the metabolism of carbon source.

• 한국식품과학회지
• /
• 제21권1호
• /
• pp.164-172
• /
• 1989

Streptococcus thermophilus 510의 ${\beta}-galactosidase$는 유당을 가수분해 하는 동시에 galactose전이반응을 일으켜 세 종류의 galactooligosaccharides를 형성 하였다. Oligosaccharide의 최대 생성 조건은 40% 유당 용액에 효소 50 ONPG units/ml를 첨가한 혼합액을 $37^{\circ}C$에서 4시간 반응시켰을 때 이며, 이 조건에서 유당이 약 94% 가수분해 되었고 생성된 oligosaccharides의 양은 총 당의 약 30% 이었다. 생성된 총 oligosaccharides의 69%는 $6-o-{\beta}-D-galactopyranosyl-D-glucose(allolactose)$, 23%는 $6-o-{\beta}-D-galactopyranosyl-D-galactose(isogalactobiose)$ 이었으며, 형성된 galactooligosaccharides을 Bio-Gel P-2 gel permeation chromatography 방법에 의해서 순수하게 분리 정제하여 구조를 조사하여 본 결과 glucose, galactose, allolactose, 그리고 isogalactobiose 임을 확인할 수 있었다.

• 한국축산식품학회지
• /
• 제35권4호
• /
• pp.572-576
• /
• 2015

The most commonly used infant formulas contain lactose originating from cow milk. Goat milk has recently been claimed to be nutritionally more effective for infants than other milks. In baby foods, much emphasis is placed on the concentrations of intestinal microflora-promoting oligosaccharides, which are generally transferred into lactose from milk during crystallization process. Here we show that higher level of free sialic acid is present in goat lactose powder compared to cow lactose powder. Without proteinase K treatment, the amount of 3-sialyllactose and 6-sialyllactose were similar in goat and cow lactose powders. However, after proteolysis, 6-sialyllactose was present at higher levels in goat than in cow lactose powder. Galactooligosaccharides, a group of prebiotics, are present in milk in the form of glycoproteins. Galactooligosaccharide content was also higher in goat lactose powder than in cow lactose powder.

• Journal of Microbiology and Biotechnology
• /
• 제22권11호
• /
• pp.1486-1493
• /
• 2012

In this study, we investigated whether galactooligosaccharide (GOS) can be stably and steadily synthesized using immobilized ${\beta}$-galactosidase (${\beta}$-gal) inclusion body (IB)-containing E. coli cells during long-term repeated-batch operation. To improve the operational stability of this enzyme reactor system, immobilized E. coli cells were crosslinked with glutaraldehyde (GA) after immobilization of the E. coli. When we treated with 2% GA for E. coli crosslinking, GOS production continued to an elapsed time of 576 h, in which seven batch runs were operated consecutively. GOS production ranged from 51.6 to 78.5 g/l ($71.2{\pm}10.5$ g/l, n = 7) during those batch operations. In contrast, when we crosslinked E. coli with 4% GA, GOS production ranged from 31.5 to 64.0 g/l ($52.3{\pm}10.8$, n = 4), and only four consecutive batch runs were operated. Although we did not use an industrial ${\beta}$-gal for GOS production, in which a thermophile is used routinely, this represents the longest operation time for GOS production using E. coli ${\beta}$-gal. Improved stability and durability of the cell immobilization system were achieved using the crosslinking protocol. This strategy could be directly applied to other microbial enzyme reactor systems using cell immobilization to extend the operation time and/or improve the reactor system stability.

• 한국식품영양과학회지
• /
• 제41권4호
• /
• pp.533-538
• /
• 2012

가래떡의 노화 특성을 분석하기 위하여 갈락토올리고당(50%)과 말토올리고당을 쌀가루 기준으로 각각 10% 농도로 첨가하여 쌀가루의 pasting 특성을 측정하였고, 가래떡을 제조하여 $5^{\circ}C$ 냉장 보관하면서 0, 2, 6, 24 및 30시간 경과 후 텍스처의 변화를 Texture Analyzer에 의해 측정하여 실험군의 떡을 무첨가군 떡과 비교하였다. 그리고 가래떡의 노화도는 텍스처 특성 중에서 0, 2, 4, 6, 22, 24, 28 및 30시간 경과 후 경도의 변화를 이용하여 Avrami 방정식에 따라 실험군의 떡을 무첨가군 떡과 비교하였다. 갈락토올리고당(50%)과 말토올리고당을 첨가한 실험군의 pasting 특성에서 peak(P) viscosity는 무첨가군에 비해 낮게 나타났고, hot paste viscosity(H)는 높게 나타났다. Breakdown(P-H)과 consistency(C-H)는 모든 실험군에서 무첨가군에 비해 낮게 나타나 올리고당을 10%를 첨가한 실험군에서 노화억제 효과가 있는 것으로 나타났다. 텍스처 특성 중 경도의 경우 실험군은 무첨가군에 비해 감소하는 경향으로 노화를 억제하는 효과를 보여 주었다. Avrami 방정식에 따른 노화 특성 분석 결과는 Avrami($n$)지수 값은 무첨가군보다 약간 높은 범위였으나 노화의 속도를 나타내는 시간상수(1/$k$)는 무첨가군 떡의 경우 43.29이었고 실험군의 경우는 82.64에서 84.75 범위로 무첨가군에 비해 그 값이 높았으며 노화속도가 느린 것으로 나타났다. 따라서 무첨가군에 비교하여 실험군 모두 경도가 낮고 노화 진행속도가 느린 것으로 나타나 갈락토올리고당(50%)과 말토올리고당을 가래떡 제조 시 10% 수준으로 첨가하면 노화억제 효과가 있는 것으로 확인되었다.

• Journal of Microbiology and Biotechnology
• /
• 제8권5호
• /
• pp.484-489
• /
• 1998

Galactooligosaccharides (GalOS) were efficiently produced by partially purified $\beta$-galactosidase from the yeast strain Bullera singularis ATCC 24193. Ammonium sulfate precipitation and ultrafiltration methods were used to prepare the enzyme. The enzyme activity decreased at $50^{\circ}C$ and above. A maximum yield of 40% (w/w) GalOS, corresponding to 120 g of GalOS per liter, was obtained from 300 g per liter of lactose solution at $45^{\circ}C$, pH 3.7 when the lactose conversion was 70%. The yield of GalOS did not increase with increasing initial lactose concentration but the total amounts of GalOS did. Volumetric productivity was 4.8 g of GalOS per liter per hour. During this reaction, the by-products, glucose and galactose, were found to inhibit GalOS formation. Reaction products were found to be comprised of disaccharides and trisaccharides according to TLC and HPLC analyses. We propose the structure of the major product, a trisaccharide, to be ο-$\beta$-D-galactopyranosyl-(l-4)-ο-$\beta$-D-galactopyranosyl-(l-4)-$\beta$-D-glucose (4'-galactosyl lactose).

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제6권5호
• /
• pp.337-340
• /
• 2001

A galactooligosaccharide(GalOS)-producing yeast, OE-20 was selected from forty seven strains of yeast growing in Korean traditional Meju (cooked soybean) and the yeast was tentatively identified as Kluyveromyces maxianus var lactis by its morphology and fermentation profile. A maximum yield of 25.1%(w/w) GalOS, which corresponds to 25.1 g of GalOS per liter, was obtained from the reaction of 100 g per liter of lactose solution at 3$0^{\circ}C$, pH 7.0 for 18 h with an intracellular crude $\beta$-galactosidase. Glucose and galactosidase were found to inhibit GalOS formation. The GalOS that were purified by active carbon and celite 545 column chromatography were supplemented in MRS media and a stimulated growth was observed of some intestinal bacteria. In particular the growth rate of Bifidobacterium infantis in the GalOS containing MRS broth increased up to 12.5% compared to that of the MRS-glucose broth during a 48h incubation period.

• 한국식품조리과학회지
• /
• 제17권5호
• /
• pp.431-440
• /
• 2001

This study was carried out to investigate the effects of oligosaccharide addition on Jeung-Pyun fermentation. Fructooligosaccharide (FOS), isomaltooligosaccharide (IMOS), galactooligosaccharide (GOS) were used at the concentration of 15%, 25% or 35% of the rice in Jeung-Pyun ingredients. The physicochemical properties, sensory evaluation and instrumental characteristics were examined. The internal structure of Jeung-Pyun samples was observed by SEM. The pH of Jeung-Pyun batters was decreased as the fermentation progressed. Compared with the control using sucrose, the specific volume of Jeung-Pyun was higher in the 15% and 25% of oligosaccharide-added samples. The degree of gelatinization decreased more slowly than control as the storage time increased both at 20$\^{C}$ and 4$\^{C}$. In sensory evaluation, Jeung-Pyun with FOS and IMOS at the levels of 25∼35% and GOS at the levels of 25% showed the best scores. In instrumental characteristics, springiness, gumminess, hardness and cohesiveness were similar among all samples during storage at 20$\^{C}$ and 4$\^{C}$. In the internal structure of Jeung-Pyun observed by SEM, Jeung-Pyun substituted with oligosaccharide at the levels of 25% for sucrose showed large and regularly distributed air pores. In conclusion, the replacement of sucrose with oligosaccharide in Jeung-Pyun ingredients appeared acceptable in terms of fermentative aspects.

• Asian-Australasian Journal of Animal Sciences
• /
• 제18권8호
• /
• pp.1199-1208
• /
• 2005

Abatement of greenhouse gas emitted from ruminants and promotion of biogas energy from animal effluent were comprehensively examined in each anaerobic fermentation reactor and animal experiments. Moreover, the energy conversion efficiency of biomass energy to power generation were evaluated with a gas engine generator or proton exchange membrane fuel cell (PEMFC). To mitigate safely rumen methanogenesis with nutritional manipulation the suppressing effects of some strains of lactic acid bacteria and yeast, bacteriocin, $\beta$1-4 galactooligosaccharide, plant extracts (Yucca schidigera and Quillaja saponarea), L-cysteine and/or nitrate on rumen methane emission were compared with antibiotics. For in vitro trials, cumulative methane production was evaluated using the continuous fermented gas qualification system inoculated with the strained rumen fluid from rumen fistulated Holstein cows. For in vivo, four sequential ventilated head cages equipped with a fully automated gas analyzing system were used to examine the manipulating effects of $\beta$1-4 galactooligosaccharide, lactic acid bacteria (Leuconostoc mesenteroides subsp. mesenteroides), yeast (Trichosporon serticeum), nisin and Yucca schidigera and/or nitrate on rumen methanogenesis. Furthermore, biogas energy recycled from animal effluent was evaluated with anaerobic bioreactors. Utilization of recycled energy as fuel for a co-generator and fuel cell was tested in the thermophilic biogas plant system. From the results of in vitro and in vivo trials, nitrate was shown to be a strong methane suppressor, although nitrate per se is hazardous. L-cysteine could remove this risk. $\beta$1-4 galactooligosaccharide, Candida kefyr, nisin, Yucca schidigera and Quillaja saponarea are thought to possibly control methanogenesis in the rumen. It is possible to simulate the available energy recycled through animal effluent from feed energy resources by making total energy balance sheets of the process from feed energy to recycled energy.

• 축산식품과학과 산업
• /
• 제9권1호
• /
• pp.70-77
• /
• 2020