• Asian-Australasian Journal of Animal Sciences
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• v.15 no.11
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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.

• Proceedings of the Botanical Society of Korea Conference
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• 2002.04a
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• pp.89-89
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• 2002

• Korean Journal of Food Science and Technology
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• v.20 no.1
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• pp.95-99
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• 1988

The changes of texture, composition of cell wall polysaccharides, polygalacturonase (PG) activity and soaking effect during preserving of persimmon at various tempoeratures were estimated for the purpose of investigating the softening characteristics of persimmon fruit. The softening of persimmon was most promoted at $25^{\circ}C$, where in the higher temperature, at $45^{\circ}C$ it was inhibited. During softening adhesiveness increased, cohesiveness and gumminess decreased. This phenomenon was obvious at $25^{\circ}C$. By soaking in water at $50^{\circ}C,\;70^{\circ}C$ for 30 minutes PG activity and softening was inhibited. Ionically associated pectin (IAP) and covalently bounded pectin (CBP) fractionated from crude cell wall of fresh persimmon were respectively degraded about 60% by PG curde enzyme of softened persimmon. And the degraded ratio of polysaccharides composed of pentose and hexose was very similar to that of polyuronide.

• Korean Journal of Plant Tissue Culture
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• v.25 no.6
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• pp.477-485
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• 1998

To underatand in vitro regulation of differentiation, the effects of growth regulators and nitrogen source on metabolism of cell wall polysaccharides in suspension culture of kidney bean (Phaseolus vulgaris L.) were investigated. The suspension cells (cell clusters) were directly induced from the epicotyl segments of the seedlings, which were cultivated in MS medium supplemented with 1.0mg/L of 2,4-D and 0.5 mg/L of kinetin. When compared with cell wall sugar contents of the epicotyl segments, the cellulose content of the suspension-cultured cells decreased; while the pectin and hemicellulose content increased; suggesting increases of rhamnogalacturonan I and arabinogalactan IIduring the dedifferentiation, respectively, The effects of growth regulators(2,4-D, 1.0mg/L and kinetin, 0.5mg/L) and nitrogen source (potasium nitrate, 19.0mg/L and ammonium nitrate, 16.5 g/L) in the medium on the proliferation and the turnover of the cell wall polysaccharides were investigated for 30 days. In the medium with growth regulators and without nitrogen source, the proliferation rate was extremely high (16 folds). Growth regulators and nitrogen source increased the pectin content. Analysis of neutral sugar composition of pectin fraction showed that nitrogen source enhanced rhamnose level remarkably, suggesting that rhamnogalacturonan I was the one most likely synthesized. In hemicellulose fraction, growth regulators reduced arabinose level, suggesting that arabinogalactan II was degraded. And nitrogen source reduced galactose level, suggesting that xyloglucan was also degraded.

• Journal of Plant Biology
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• v.29 no.4
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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.

• Microbiology and Biotechnology Letters
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• v.22 no.3
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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.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.3
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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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• v.42 no.4
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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.

• Proceedings of the Zoological Society Korea Conference
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• 1997.10b
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• pp.202.2-202
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• 1997

No Abstract, See Full Text

• Korean Journal of Food Science and Technology
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• v.22 no.7
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• pp.738-742
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• 1990

Cell wall components were decreased during maturation and postharvest of persimmon fruits. Contents of pectin and alkali-soluble hemicellulose were increased during maturity, but those of acid-soluble hemicellulose were decreased. Contents of pectin and alkali-soluble hemicellulose were decrease in soft persimmon, whereas acid-soluble hemicellulose was increased remarkably. Cellulose contents were increased during maturation and this tend was notable in soft persimmon. Contents of cell wall polysaccharides per 100g-fresh weight were decreased. Contents of total pectin and insoluble pectin were increased during maturation but decreased in soft persimmon. Content of water-soluble pectin was increased during maturation and postharvest.