• Applied Biological Chemistry
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• 제47권4호
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• pp.379-383
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• 2004

Bacillus sp. 유래 ${\beta}-mannanase$의 brown copra meal에 대한 기질 특이성을 규명하기 위하여 정제효소 150 ml를 0.5% 기질에 $50^{\circ}C$, 24 hrs 가수분해후 TLC, FACE로 비교 검토한 결과 2종류의 galactosyl mannooligosaccharide로 구성되어 1차 activated carbon column chromatography을 이용해 250 ml/hr 유속으로 tube당 50ml씩 ethanol $0{\sim}30%$ linear gradient로 당을 분리하였다. Activated carbon column chromatography에 의한 당용액 0.2 ml와 5% phenol 0.2 ml를 가하여 혼합 후 $Conc.H_2SO_4$ 1 ml를 가하여 혼합한 후 20분간 방치하여 490 nm로 흡광도를 측정하여 TLC로 pattern을 검토한 후 $Gal^3Man_4$ 및 DP 7의 galactosyl manooligosaccharide의 fraction을 회수하여 2차 activated carbon column chromatography를 이용해 1차와 동일한 조전에서 분리 회수하여 중합도 5는 $Gal^3Man_4(63-mono-{\alpha}-D-galactopyranosyl-{\beta}-mannotetraose)$로 동정되었고, 중합도 7은 현재 동정중에 있다. Bifidobacterium속 균주(B. longum, B. bifidum)에 대한 생육활성을 비교 검토하기 위하여 MRS media에서 탄소원을 dextrose대신에 조제된 $Gal^3Man_4$를 첨가후 측정한 결과 $Gal^3Man_4$이 첨가되지 않은 MRS broth에 비해 생육촉진 활성을 보였다. 특히 B. longum에 대해서는 $Gal^3Man_4$를 dextrose대체 탄소원으로 처리시 10배의 생육활성이 증가하였다.

• 한국식품과학회지
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• 제33권3호
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• pp.282-287
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• 2001

인삼 조사포닌을 기존의 고온 MeOH 추출/n-BuOH 분획법 및 고온 MeOH 추출/Diaion HP-20 흡착/MeOH 용출법과 새로이 시도된 고온 MeOH 추출/cation AG 50W흡착/$H_2O$ 용출/n-BuOH 추출법(AG 50W법), 상온 MeOH 추출/Diaion HP-20 흡착/MeOH 용출법(상온추출법)과 EtOAc/n-BuOH 직접 추출법으로 분리한 다음 기존의 HPLC/RI 방법으로 ginsenoside조성을 비교한 결과 EtOAc/n-BuOH 직접 추출법을 제외하고는 큰 차이가 없었으나 분리능과 감도가 우수한 HPLC/ELSD방법을 사용한 결과, ginsenoside $Rb_2$, Rf, $Rg_1$ 및 $Rh_1$ 등을 뚜렷이 식별할 수 있었고 추출 및 분획방법에 따라 조사포닌간 ginsenoside의 현저한 조성차이를 볼 수 있었다. 특히 AG 50W법에 의해 분리된 조사포닌에서 뚜렷한 prosapogenin 피크를 볼 수 있었으며 LC/MS의 결과, ginsenoside $Rb_1$, $Rb_2$ 등의 7종의 주종 사포닌 이외에도 5종의 prosapogenin과 1종의 chikusetsusaponin을 포함한 총 13종의 ginsenoside를 동정하였다. 새로이 정립한 HPLC 분석조건, 즉 $NH_2$ 대신에 $C_{18}$ column을 사용하고 $KH_2PO_4/CH_3CN$ gradient로 상온추출법으로 분리한 조사포닌을 분석한 결과, malonyl ginsenoside 피크를 용이하게 확인할 수 있었다.

• Asian-Australasian Journal of Animal Sciences
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• 제30권7호
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• pp.957-966
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• 2017

Objective: To understand the dynamic structure, function, and influence on nutrient metabolism in hosts, it was crucial to assess the genetic potential of gut microbial community in yaks of different ages. Methods: The denaturing gradient gel electrophoresis (DGGE) profiles and Illumina-based metagenomic sequencing on colon contents of 15 semi-domestic yaks were investigated. Unweighted pairwise grouping method with mathematical averages (UPGMA) clustering and principal component analysis (PCA) were used to analyze the DGGE fingerprint. The Illumina sequences were assembled, predicted to genes and functionally annotated, and then classified by querying protein sequences of the genes against the Kyoto encyclopedia of genes and genomes (KEGG) database. Results: Metagenomic sequencing showed that more than 85% of ribosomal RNA (rRNA) gene sequences belonged to the phylum Firmicutes and Bacteroidetes, indicating that the family Ruminococcaceae (46.5%), Rikenellaceae (11.3%), Lachnospiraceae (10.0%), and Bacteroidaceae (6.3%) were dominant gut microbes. Over 50% of non-rRNA gene sequences represented the metabolic pathways of amino acids (14.4%), proteins (12.3%), sugars (11.9%), nucleotides (6.8%), lipids (1.7%), xenobiotics (1.4%), coenzymes, and vitamins (3.6%). Gene functional classification showed that most of enzyme-coding genes were related to cellulose digestion and amino acids metabolic pathways. Conclusion: Yaks' age had a substantial effect on gut microbial composition. Comparative metagenomics of gut microbiota in 0.5-, 1.5-, and 2.5-year-old yaks revealed that the abundance of the class Clostridia, Bacteroidia, and Lentisphaeria, as well as the phylum Firmicutes, Bacteroidetes, Lentisphaerae, Tenericutes, and Cyanobacteria, varied more greatly during yaks' growth, especially in young animals (0.5 and 1.5 years old). Gut microbes, including Bacteroides, Clostridium, and Lentisphaeria, make a contribution to the energy metabolism and synthesis of amino acid, which are essential to the normal growth of yaks.

• 미생물학회지
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• 제33권3호
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• pp.175-180
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• 1997

인위적으로 pH 구배가 조성딘 회분배양 시스템(batch culture system)내에서 종속영양 세균 군집의 종조성 변화에 미치는 산성화의 영향을 수리학적으로 분석하였다. 총세균의 개체수는 산성화에 영향을 받지 않았으며, 종속영양 세균 군집의 크기는 pH가 낮아질수록 감소하였다. 전 pH 구간에서 분리된 종속영양 세균들은 모두 12속 22종으로 나타났으며, 이중 그람음성 세균은 64%, 그람양성 세균은 36%의 비율로 분포하였다. pH가 낮아짐에 따라 그람양성 세균의 분포 비율은 감소하는 반면, 그람음성 세균의 분포 비율은 증가하는 양상을 보였다. 각 pH 구간별 속의 분포 비율은 pH 7에서는 12개 속이 출현하였으나, pH 3에서는 5개 속만 출현하여 pH가 낮아짐에 따라 속의 다양성이 감소하는 양상을 나타내었다. 종 다양성 지수는 1.13-2.37이 범주였으며, pH가 낮아질수록 종 다양성 지수가 낮게 나타났다. 크기가 다른 군집의 다양성 평가를 위해 rarefraction 방법으로 pH에 따른 종 출현의 기대값을 분석한 결과 역시 pH가 낮아질수록 기대값(expected number)이 낮은 것으로 나타남으로써 종 다양성 지수에 대한 유의성을 검정하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제18권5호
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• pp.704-710
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• 2005

The objective of this experiment was to compare corn and wheat in finishing pig diets in order to determine whether performance, carcass quality, fatty acid composition or fat colour is altered by choice of cereal grain. A total of 126 crossbred pigs were used in this experiment. At the start of the experiment, a portion of the experimental animals were assigned to receive a wheat-based diet formulated using soybean meal as the sole source of supplementary protein. The remainder of the pigs were assigned to a corn-based diet formulated to supply a similar level of lysine (0.65%) and energy (3,300 kcal/kg DE). At two week intervals, a portion of the pigs on the corn-based diet were switched to the wheat-based diet so that a gradient was produced with pigs being fed the corn and wheatbased diets for different proportions of the finishing period ranging from 100% on wheat to 100% on corn. There were no significant differences in the growth rate of pigs fed the two diets (p = 0.834). Pigs fed wheat tended to consume slightly less feed (p = 0.116) and had a significantly improved feed conversion (p = 0.048) compared with pigs fed corn. Choice of cereal did not affect dressing percentage (p = 0.691), carcass value index (p = 0.146), lean yield (p = 0.134), loin fat (p = 0.127) or loin lean (p = 0.217). Fatty acid composition of backfat was unaffected by the cereal grain fed (p>0.05). Total saturated fatty acid content was 33.31% for both corn and wheat fed pigs (p = 0.997) while the polyunsaturated fatty acid content was 12.01% for corn fed pigs and 11.21% for wheat fed pigs (p = 0.257). The polyunsaturated/saturated ratio was 0.36 for pigs fed corn and 0.34 for pigs fed wheat (p = 0.751). Hunter Lab Colour Scores indicated no difference either in the whiteness or yellowness of the fat. In conclusion, wheat can substitute for corn in growingfinishing pig rations without detrimental effects on pig performance. There were no differences in either the fatty acid composition of backfat or in backfat colour indicating that the decision to use wheat vs. corn needs to be made on economic grounds rather than being based on their effects on fat quality.

• Journal of Microbiology and Biotechnology
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• 제18권4호
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• pp.711-717
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• 2008

To speed up the conversion of rice straw into feeds in a low-temperature region, a start culture used for ensiling rice straw at low temperature was selected by continuous enrichment cultivation. During the selection, the microbial source for enrichment was rice straw and soil from two places in Northeast China. Lab-scale rice straw fermentation at $10^{\circ}C$ verified, compared with the commercial inoculant, that the selected start culture lowered the pH of the fermented rice straw more rapidly and produced more lactic acid. The results from denatured gradient gel eletrophoresis showed that the selected start culture could colonize into the rice straw fermentation system. To analyze the composition of the culture, a 16S rRNA gene clone library was constructed. Sequencing results showed that the culture mainly consisted of two bacterial species. One (A) belonged to Lactobacillus and another (B) belonged to Leuconostoc. To make clear the roles of composition microbes in the fermented system, quantitative PCR was used. For species A, the DNA mass increased continuously until sixteen days of the fermentation, which occupied 65%. For species B, the DNA mass amounted to 5.5% at six days of the fermentation, which was the maximum relative value during the fermentation. To the authors' best knowledge, this is the first report on ensiling rice straw with a selected starter at low temperature and investigation of the fermented characteristics.

• Journal of Forest and Environmental Science
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• 제28권4호
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• pp.199-204
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• 2012

This study was conducted to estimate climax index by eco-morphology for major 36 tree and sub-tree species in natural deciduous forests so as to interpret seral position of each species in the forest community. Fourteen eco-morphological characters which were considered to be associated with successional gradient in the forest were selected for the study. Four levels per character for each species were given on a standardized scale of increasing climax, and the index was computed by the proportion of the sum of total scores, expressed by percent values. With calculated mean value of 54.8 for all indices, Carpinus cordata had the highest index value of 90.5, and Populus davidiana recorded the lowest of 13.2. The most climax group, greater than 70 of the index, contained only 8 species, intermediate group, between 41 to 70 of the index, had 23 species, and the most pioneer group, less than 40 of the index comprised 5 species. The result has noticed that the large number of species would take advantage of most diverse resource and niche in the intermediate stage of the sere in the forest. By cluster analysis all 36 species were subjected to be classified into several species groups which had common similar eco-morphological characteristics. The indices were additionally plotted on the two dimensional graph to recognize the positions related to the light absorption factor and reproduction factor. The climax index of tree and sub-tree species developed by this study could be applied to understand the present status of successional stage on the basis of species composition by the method of summing up the indices. And comparison of forest successional stage among various forest communities could be done by summing up the climax indices of composed species in each community. However, this kind of applied methodology should be limited to the forest of similar species composition and site condition.

• 한국결정성장학회지
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• 제9권6호
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• pp.542-546
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• 1999

InP single crystal, III-V binary compound semiconductor, was grown by VGF(vertical gradient freeze) method using quartz ampoule and its electrical optical properties were investigated. Phosphorous powders were put in the bottom of quartz ampoule and Indium metal charged in conical quartz crucible what was attached at the upper side position inside the quartz ampoule. It was vacuous under the pressure of $10^5$Torr and sealed up. Indium metal was melted at $1070^{\circ}C$ and InP composition was formed by diffusion of phosphorous sublimated at $450^{\circ}C$ into Indium melt. By cooling the InP composition melt ($2^{\circ}C$~$5^{\circ}C$/hr of cooling rate) in range of $1070^{\circ}C$~$900^{\circ}C$, InP crystal was grown. The grown InP single crystals were investigated by X-ray analysis and polarized optical microscopy. Electrical properties were measured by Van der Pauw method. At the cooling method. At the cooling rate of $2^{\circ}C$/hr, growth direction of ingot was [111] and the quality of ingot was better at the upper side of ingot than the lower side. It was found that the InP crystals were n-type semiconductor and the carrier concentration, electron mobility and relative resistivity were $10^{15}$~$10^{16}/\textrm{cm}^3$ , $2\times 10^3$~$3\times 10^4{\textrm}{cm}^2$/Vsec and$2\times 10^{-1}$~$2\times 10^{-3}$/ Wcm in the range of 150K~300K, respectively.

• Preventive Nutrition and Food Science
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• 제3권3호
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• pp.211-215
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• 1998

Preparative isolation of lipid granules from Fhodotorula glutinis, which has been studied for long time to produce edible lipids, was carried out by flotation method in Ficoll-Linear density gradient. When the isolated lipid granules were suspended in a series of solutions containing varying concentration of osmotic stabilizer (sorbitoal and mannitol) ranging from 0.8M to 0M, the lipid granules appeared to be disrupted at a concentration between 0.8M and 0.7, and again at a concentration below 0.1M, suggesting that lipid granules have a membraneous structure and that at least two types of lipid granules are present. Compositional analysis of lipids from lipid granules revealed that lipids are composed mainly of neutral lipids (87.8% of total lipids), predominantly as triacylglycerols (71.89%). Marked differences were observed inphospholipids between lipids of lipid granules and those of whole cells . The major components of phospholipids in lipid granules and inwhole cells are phosphatidylcholine(38.6%) and phosphatidylserine(42.8%), respectively. In addition, significant differences were also observed in the fatty acid composition of phospholipids. As phospholipids are important structural components of membranes, these differences lead to the suggesting that the membrane of lipid granules may be distinct functionally and structurally from other membranes of yeast cells. The major fatty acid components of neutral lipidss of whole cells and lipid granules are palmitic , oleic and linoleic acid. However , degreeof fatty acid unsaturation of neutal lipids of lipid granules was much lower than that of neutral lipids of whole cells.

• Journal of Ecology and Environment
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• 제39권1호
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• pp.17-29
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• 2016

We conducted the study on the relationship between the distribution of coastal sand dune plants and edaphic factors from the shoreline to inland in sand dune ecosystem. The application of TWINSPAN classification based on 10 species, led to the recognition of three vegetative groups (A-C), which associated with their habitats (foredune, hummuck in semistable zone and stable zone). The associations were separated along soil gradient far from the seashore. The relationships between species composition and environmental gradients were explained by canonical correspondence analysis (CCA). Distance from the shoreline was an important indicator to determine soil properties (pH, total ion contents, sand particle sizes, organic matters and nitrogen contents) from the seaward area to inland area and distribution pattern of coastal sand dune plants. Group A is foredune zone, characterized by Calystegia soldanella; group included typical foredune species such as Elymus mollis, Carex kobomugi, Ixeris repens, C. soldanella and Glehnia littoralis. Group B on semi-stabilized zone was characterized by Vitex rotundifolia, a perennial woody shrub. This group was associated the proportion of fine sand size (100 to 250 μm). The results on the proportion of soil particle size showed a transition in sand composition, particularly with respect to the proportion of fine sand size that occurred from the foredune ridge at 32.5 m to the Vitex rotundifolia community at 57.5 m from the shoreline. Group C on stabilized zone was characterized by Zoysia macrostachya, Lathyrus japonicus and Cynodon dactylon and were associated soil organic matter and nitrogen contents. The spatial distribution of plants in the Goraebul coastal sand dune system may result from the interactions between the plant species and environmental heterogeneity.