• KSBB Journal
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• v.31 no.4
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• pp.277-283
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• 2016

In this system, rice cells were genetically modified to express human cytotoxic T-lymphocyte antigen 4-immunoglobulin (hCTLA4Ig) using RAmy3D promoter induced by sugar depletion. Even though the target protein fused with signal sequence peptide, plant cell wall can be a barrier against secretion of recombinant proteins. Therefore, hCTLA4Ig can be trapped inside cell wall or remained in intracellular space. In this study, to enhance the secretion of hCTLA4Ig from cytoplasm and cell walls into the medium, permeabilizing agents, such as dimethyl sulfoxide (DMSO), Triton X-100 and Tween 20, were applied in transgenic rice cell cultures. When 0.5% (v/v) of DMSO was added in sugar-free medium, intracellullar hCTLA4Ig was increased, on the other hand, the secreted extracellular hCTLA4Ig was lower than that of control. DMSO did not give permeable effects on transgenic rice cell cultures. And Triton X-100 was toxic to rice cells and also did not give enhancing permeability of cells. When 0.05% (v/v) Tween 20 was added in rice cell cultures, however, intracellular hCTLA4Ig was lower than that of control cultures. And the maximum 44.76 mg/L hCTLA4Ig was produced for 10 days after induction, which was 1.4-fold increase compared to that of control cultures. Especially, Tween 20 at 0.05% (v/v) showed the positive effect on the secretion of hCTLA4Ig though the decrease of intracellular hCTLA4Ig. Also, Tween 20 as a non-toxic surfactant did not affect the cell growth, cell viability and protease activity. In conclusion, secretion of hCTLA4Ig could be increased by enhancing permeability of cells regardless of the cell growth, cell viability and protease activity.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.522-526
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• 1999

Bactericidal effects of chitosans with varying molecular weight $(10,000{\sim}170,000)$ were investigated for Streptococcus mutans, a primary causative bacterium of dental caries. The molecular weight of chitosan was a significant contributor to the bactericidal effect, and a chitosan having approximately 30,000 of molecular weight exhibited the highest bactericidal effects on S. mutans. Treatment of chitosan resulted in leaking intracellular protein and nucleic acid out of S. mutans cells. In addition, the divalent cations such as $Ca^{2+}\;and\;Mg^{2+}$ were also significantly released out of the cell. Visible damage of chitosan treated cells was observed by transmission electron microscopy (TEM), in which the cell wall was notably distorted and cytoplasmic membrane was separated from the cell wall. The results suggested that the bactericidal effect of chitosan on S. mutans was attributable to both leakage of intracellular materials and structural disintegration of cell wall.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.7
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• pp.1049-1053
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• 1999

Chopped wheat straw (0.5-1.5 cm) was subjected to different treatment combinations in a $5{\times}4$ factorial arrangement involving the five levels of urea (0, 2, 3, 4 and 5%, w/w) and four levels of lime (0, 2, 4 and 6%, w/w) at 50% moisture and kept for 3 wk reaction period at about $35{^{\circ}C}$ in laboratory. Treated wheat straw samples were analyzed to study the associative effect of urea and lime on chemical composition, in sacco and in vitro digestibilities. Results showed that cell wall constituents (CWC) solubilized significantly (p<0.01) due to urea and lime treatment on one hand and substantially increase the crude protein (CP) on the other in wheat straw. The main effect on synergism of both chemicals was noticed on organic matter (OM), neutral detergent fibre (NDF), hemicellulose (HC), acid detergent lignin (ADL) and silica by solubilising their contents as a result of considerable increase in cell contents in treated wheat straw. The respective decreases were 5.45, 13.0, 37.23, 44.95 and 26.16% in different treatment combinations. The most interesting feature of the treatment was evident by increase in ash content on each level of lime application. CP content increase up to 12.78% due to urea treatment in comparison with untreated wheat straw (2.56%). The effect of solubilization of structural carbohydrates and increased crude protein due to synergistic effect of urea and lime were clearly seen on improved digestibility of OM and DM. The increase in ISOMD, ISDMD, and IVDMD were 21.67, 21.67, 16.24, and 17.5 units. The increase in digestibility were relative to additions of both chemicals and digestibility values increased with increasing levels of urea plus lime concentration in different treatment combination. The maximum improvement was noticed at 4% urea and 4% lime levels at 50% moisture for 3 wk reaction period in treated wheat straw.

• Korean Journal of Microbiology
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• v.29 no.6
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• pp.397-401
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• 1991

Yeast-form cells of cadmium ion-tolerant Hansenula anomala B-7 were changed to mycelial cells in medium containing more than $400\mu$g/ml of cadmium. Moreover, the mycelial cells were exchanged into clumped cells in a medium containing more than $1,000\mu$g/ml of cadmium. Optimal conditions of mycelial cell formation were achieved in the presence of .$1,000\mu$g/ml of cadmium with shaking cultivation for 7 days. Glucan and mannan contents of the yeast cell wall frown with $1,000\mu$g/ml of cadmium decreased by 10% compared with those grown without cadmium. However, protein and lipid contents increased about 20% respectively. By cadmium, no significant findings in specific amino acid contents were discovered.

• Applied Biological Chemistry
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• v.47 no.4
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• pp.403-408
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• 2004

We studied active substances like crude cell wall components, crude protein, composing amino acids and free amino acids including orinithine cycle-related amino acids such as asparagine, ornithine and citrullin in fully ripe fruits of Korean native squash, Cucurbita moschata Poir. Crude protein content of 'Jeju 2' was the highest with $2,830\;{\mu}g/g$, while 'Sangju' was the lowest with $1,319\;{\mu}g/g$. Regarding the contents of crude cell wall components, fruit 'Kanghaw' was the highest with 2,961 mg% while 'Namhea' was the lowest with 1,582 mg%. Pectin contents of crude cell wall components were the highest in 'Kanghaw' (2,198 mg%) followed by 'Jeju 2' (2,178 mg%) and 'Jeju l' (1,461 mg%). The main contents of amino acids in squash were glutamic acid, aspartic acid, lysine, leucine and valine, which comprised to be more than 50% of total amino acid contents. Especially, in 'Jeju 2' aspartic acid and threonine were not detected. In fully ripe fruits, a total of 34 kinds of free amino acids were detected including 8 kinds of essential amino acids (histidine, isoleucine, leucine, lysine, phenylalanine, methionine, threonine and valine). More than 50% of the total free amino acids were aspartic acid and asparagine, and also all varieties were detected in ornithine, citrullin, and arginine, which are related to Ornithine cycle. There was a big difference in the contents of arginine in all varieties whereas the contents of ornithine and citrullin were very similar. 'Teaan' 29.34% was 7 times higher than 'Namhea' 4.30% in regards to arginine contents.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.1
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• pp.44-49
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• 2003

Effects of supplementation with ruminal epithelial cells on fiber-degrading activity and cell growth of Ruminococcus albus (R. albus, strain 7) was tested using a basal substrate of rice straw and formulated concentrate. Cultures of R. albus alone and R. albus with rumen protozoa were grown at $39^{\circ}C$ for 48 h with an 8.4% crude protein (CP) substrate, 33% of the CP supplemented with either ruminal epithelial cells or defatted soybean meal. The ruminal epithelial cells had lower amounts of rumen soluble and degradable protein fractions as compared to defatted soybean meal, as determined by an enzymatic method, and the same was found with amino acid composition of protein hydrolysates. Ruminal epithelial cells were directly utilized by the R. albus, and resulted in greater growth of cell-wall free bacteria compared to defatted soybean meal. The effect of epithelial cells on bacterial growth was enhanced by the presence of rumen protozoa. In consistency with cultures of R. albus and R. albus with rumen protozoa, fermentative parameters such as dry matter degradability and total volatile fatty acid did not differ between supplementation with ruminal epithelial cells or defatted soybean meal.

• Journal of Microbiology and Biotechnology
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• v.26 no.1
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• pp.38-43
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• 2016

Novel and specific recognition elements are of central importance in the development of a pathogen detection method. Here, we describe a simple method for identifying the cell-wall binding domain (CBD) from a sequenced bacterial genome employing homology search for phage lysin genes. A putative CBD (CPF369_CBD) was identified from a genome of Clostridium perfringens type strain ATCC 13124, and its function was studied with the CBD-GFP fusion protein recombinantly expressed in Escherichia coli. Fluorescence microscopy showed the specific binding of the fusion protein to C. perfringens cells, which demonstrates the potential of this method for the identification of novel bioprobes for specific detection of pathogenic bacteria.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.1
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• pp.93-103
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• 1999

Recent advances in the biotechnology of ruminal bacteria have been made in the characterization of enzymes involved in plant cell wall digestion, the exploration of mechanisms of gene transfer in ruminal bacteria, and the development of vectors. These studies have culminated in the introduction and expression of heterologous glucanase and xylanase genes and a fluoroacetate dehalogenase gene in ruminal bacteria. These recent studies show the strategy of gene and vector construction necessary for the production of genetically engineered bacteria for introduction into ruminants. Molecular research on proteolytic turnover of protein in the rumen is in its infancy, but a novel protein high in essential amino acids designed for intracellular expression in ruminal organisms provides an interesting approach for improving the amino acid profile of ruminal organisms.

• Korean Journal of Plant Tissue Culture
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• v.27 no.5
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• pp.387-393
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• 2000

The process by which Agrobacterium tumefaciens genetically transforms plants involves a complex series of reactions communicated between the pathogen and the plants. To identify plant factors involved in agrobacterium-mediated plant transformation, a large number of T-DNA inserted Arabidopsis thaliana mutant lines were investigated for susceptibility to Agrobacterium infection by using an in vitro root inoculation assay. Based on the phenotype of tumorigenesis, twelve T-DNA inserted Arabidopsis mutants(rat) that were resistant to Agrobacterium transformation were found. Three mutants, rat1, rat3, and rat4 were characterized in detail. They showed low transient GUS activity and very low stable transformation efficiency compared to the wild-type plant. The resistance phenotype of rat1 and rats resulted from decreased attachment of Agrobacterium tumefaciens to inoculated root explants. They may be deficient in plant actors that are necessary for bacterial attachment to plant cells. The disrupted genes in rat1, rat3, and rat4 mutants were coding a arabinogalactan protein, a likely cell wall protein and a cellulose synthase-like protein, respectively.

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.454-459
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• 1985

The structure of the seed of Lupinue angustifolius was studied in order to investigate the Food quality of lupin seed in comparision with soybean. The cotyledonary cells of lupinseed was in egg-like shape and much (more than 4 times) larger than those of soybean. The microstructure of cotyledonary cells of lupinseed was characterized with thick cell wall having distinct pit-pairs. The protein bodies in lupinseed cotyledon cell contained numerous crystaloids, which was absent in soybean. The middle lamella of soybean cell was partially disintegrated by excessive heat treatment ($120^{\circ}C$, 20 min), whereas those of lupinseed did not change much by heting at $120^{\circ}C$ for 130 min.