• Asian-Australasian Journal of Animal Sciences
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• 제15권11호
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• pp.1659-1676
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• 2002

Ruminant animals develop a diverse and sophisticated microbial ecosystem for digesting fibrous feedstuffs. Plant cell walls are complex and their structures are not fully understood, but it is generally believed that the chemical properties of some plant cell wall compounds and the cross-linked three-dimensional matrix of polysaccharides, lignin and phenolic compounds limit digestion of cell wall polysaccharides by ruminal microbes. Three adaptive strategies have been identified in the ruminal ecosystem for degrading plant cell walls: production of the full slate of enzymes required to cleave the numerous bonds within cell walls; attachment and colonization of feed particles; and synergetic interactions among ruminal species. Nonetheless, digestion of fibrous feeds remains incomplete, and numerous research attempts have been made to increase this extent of digestion. Exogenous fibrolytic enzymes (EFE) have been used successfully in monogastric animal production for some time. The possibility of adapting EFE as feed additives for ruminants is under intensive study. To date, animal responses to EFE supplements have varied greatly due to differences in enzyme source, application method, and types of diets and livestock. Currently available information suggests delivery of EFE by applying them to feed offers the best chance to increase ruminal digestion. The general tendency of EFE to increase rate, but not extent, of fibre digestion indicates that the products currently on the market for ruminants may not be introducing novel enzyme activities into the rumen. Recent research suggests that cleavage of esterified linkages (e.g., acetylesterase, ferulic acid esterase) within the plant cell wall matrix may be the key to increasing the extent of cell wall digestion in the rumen. Thus, a crucial ingredient in an effective enzyme additive for ruminants may be an as yet undetermined esterase that may not be included, quantified or listed in the majority of available enzyme preparations. Identifying these pivotal enzyme(s) and using biotechnology to enhance their production is necessary for long term improvements in feed digestion using EFE. Pretreating fibrous feeds with alkali in addition to EFE also shows promise for improving the efficacy of enzyme supplements.

• 한국식물학회:학술대회논문집
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• 한국식물학회 2002년도 춘계학술발표대회:발표눈문요지록
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• pp.89-89
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• 2002

• 한국식품과학회지
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• 제20권1호
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• pp.95-99
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• 1988

온도변화에 따른 감의 텍스쳐변화와 고온담금효과 및 이에 따른 세포벽 다당류의 변화를 조사하였다. 감은 $25^{\circ}C$에서 가장 쉽게 연화되었으며 $45^{\circ}C$에서는 연화가 억제되었다. 연화가 진행되는 동안 부착성은 증가하는 한편 응집성 및 gumminess는 감소하였으며 이러한 현상은 $25^{\circ}C$에서 현저하다. $50^{\circ}C$와 $70^{\circ}C$의 물에 30분간 담금 처리 함으로써 PG의 활성이 현저하게 저해되었으며 연화도 억제되었다. 연화된 감으로부터 추출한 PG 조효소는 신선한 감의 조세포벽으로부터 분획한 세포벽다당류 중 IAP와 CBP를 각기 60%정도 분해시켰으며 그 구성 성분중 pentose와 hexose로 구성된 다당류의 분해가 polyuronide의 분해정도와 대등하였다.

• 식물조직배양학회지
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• 제25권6호
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• pp.477-485
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• 1998

감자 plastid 형질전찬을 위한 새로운 DNA 절편을 확보하고자, 감자의 trnK-matK 유전자를 PCR 방법으로 클로닝하고 특성을 조사하였다. 염기서열 분석을 통하여 trnK-matK 유전자에는 두 종류의 polymerase 인지부위[Prokaryotic site(plastid encoded polymerase)와 eukaryotic site (nuclear-encoded polymerase)]가 족재함을 알 수 있었다. 이 사실은 trnK-matK 유전자의 발현이 광합성조직과 비광합성조직에서 서로 다른 polymerase에 의하여 조절됨을 시사하였다. 한편 MatK의 아미노산서열을 분석한 결과 식물에 따라 아미노산 identity가 39-75%로 다양하였으나, 감자와 담배는 98%의 아주 높은 identity를 보였다. Northern분석을 통하여 포장과 기내에서 생육된 감자 식물체 모두에서, trnK-matK 의 전사 수준이 잎에서 높고 괴경에서는 낮음을 알 수 있었다. 한편 잎에서의 16s rDNA의 전사수준은 괴경에 비해 약 50배 높았다. 이것으로 미루어보아 괴경에서 수준이 낮을 것은, 괴경에서는 plastid genome copy 수가 적거나 plastid 수가 적기 때문으로 추정된다. 이상의 결과로서 엽록체와 amyloplst 모두에서 trunK-matK 유전자가 활발하게 발현되고 있음을 알 수 있었다. Plastid genomic DNA의 Southern 분석을 통하여 trnK는 1 copy로 존재하고, matK는 trnK intron을 포함하고 있음을 확인하였다. 따라서 감자 plastid형질전환의 새로운homologous recombination 부위로 trnK-matK유전자를 이용할 수 있을 것이다.

• Journal of Plant Biology
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• 제29권4호
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• pp.263-284
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• 1986

Effects of putrescine, spermidine and spermine on the activity of D-glucose-6-phosphate cyclohydrolase in the Daucus carota L. protoplast cultured for 4 days and effects of polyamines on the incorporation of D-[u-14C]-glucose treated to protoplasts in culture-medium were investigated. The activity of D-glucose-6-phosphate cyclohydrolase was increased by polyamines and among them spermine was the most effective. Polyamiens increased protein synthesis and this due to the increasing effect of the polyamines on the synthesis of glycoprotein which is one of cell wall components. The synthesis of cell polysaccharides, such sa pectic substances, hemicelluloses and cellulose was increased by polyamines, which stimulated synthesis of pectin substances, and hemicellulose more greatly than that of cellulose, and spermidine was the most effective. In the light of the above results it seems that the polyamines increase cell wall regeneration by the stimulation of enzyme activities which synthesize cell wall components.

• 한국미생물·생명공학회지
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• 제22권3호
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• pp.240-245
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• 1994

Relation the phage defense mechanism of phage resistant Lactococcus lactis subsp. cremoris ATCC 11602-A1 to its cell wall components was investigated. To determine whether teichoic acid which is known to be one of the phage receptor site present on the cell wall, phage adsorption was examined after treatment 5% TCA(60%$\CIRC $C) and concanavalin A to the cell wall of A1 and parent strain. However, the adsorption rate of two strains did not change. Total amount of phosphate after TCA treatment did not change in both strains, but a difference between the two strains was observed. Ribitol and glycerol, components of teichoic acid, could not be detected in the cell walls of two strains by GC analysis. These results suggest that although teichoic acid was not present in the cell walls of both strains, the composition of cell wall of two strains was not identical. Measurement of amount of protein and SDS-polyacryamide gel electrophoresis were carried out to examine the involvement of cell wall protein in phage resistance, showing that protein is nothing to do with phage adsorption of parent strain, but phage resistance of A1 is related to protein. Cell wall carbohydrates of A1 contained rhamnose, glucose, and galactose. Total amount of carbohydrate of 1% SDS-treated A1 cell wall was reduced to the level of parent strain. The results suggest that phage resistance of A1 was due to the presence of a higher level of carbohydrates then parent strain, and to interaction of carbohydrate and protein.

• 한국식품영양과학회지
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• 제27권3호
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• pp.461-470
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• 1998

The effects of addition of water extract of pine needle(WEPN) on texture and cell wall polysac-charides content of kimchi during fermentation at 1$0^{\circ}C$ were investigated. Textural properties of hardness, gumminess and cohesiveness of kimchi were higher for WEPN-added kimchi than for the control during the entire fermentation periods, while its adhesiveness was lower. Alcohol insoluble substance, among cell wall polysaccharide fractions of kimchi was higher in WEPN-added kimchi than in the control but water soluble materals was high in control during fermentation periods. The separation phenomenon of middle lamella of control kimchi tissue was observed at 14th days of fermentation but WEPN-added kimchi showed at 21th days fermentation. The vasular of kimchi tissue was more destroyed in control than in WEPN-added kimchi.

• Mycobiology
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• 제42권4호
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• pp.422-426
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• 2014

Depending on the acquisition of developmental competence, the expression of genes for ${\beta}$-1,3-glucan synthase and chitin synthase was affected in different ways by Aspergillus nidulans LAMMER kinase. LAMMER kinase deletion, ${\Delta}lkhA$, led to decrease in ${\beta}$-1,3-glucan, but increase in chitin content. The ${\Delta}lkhA$ strain was also resistant to nikkomycin Z.

• 한국동물학회:학술대회논문집
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• 한국동물학회 1997년도 한국생물과학협회 학술발표대회
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• pp.202.2-202
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• 1997

No Abstract, See Full Text

• 한국식품과학회지
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• 제22권7호
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• pp.738-742
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• 1990

감과실의 성숙과 추숙중 세포벽의 함량은 감소하는 경향이었고, 성숙중에는 pectin질과 알칼리 가용성 hemicellulose의 함량은 증가하는 반면 산 가용성 hemicellulose와 lignin은 감소하였다. 그러나 연시에서는 pectin질과 알칼리 가용성 hemicelloluse의 감소와 산가용성 hemicellulose의 증가가 뚜렷하였다. 그리고 성숙과 추숙중에 cellulose의 함량은 증가하였으며, 생체당 세포벽 다당류의 함량은 감소하였다. 총 pectin질과 불용성 pectin질의 함량은 성숙중에는 증가하였으나 연시에서는 현저히 감소하였으며, 반면에 수용성 pectin질의 함량은 성숙과 추숙중에 증가하였다.