• Journal of Microbiology and Biotechnology
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• v.4 no.4
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• pp.285-289
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• 1994

An insecticidal crystal protein gene, cryIA(c), from Bacillus thuringiensis HD-73 was integrated into the chromosome of a xanthan-producing bacterium, Xanthomonas campestris XP92. The cryIA(c) gene expression cassette was constructed that placed the gene between the trc promoter and rrnB transcriptional terminator. The $lacl^q$ gene was also included to prevent the expression of cryIA(c) gene in X campestris cells. Southem blot analysis confirmed the integration of the cryIA(c) gene expression cassette in chromosome of X campestris XP92 transconjugant. Expression of the insecticidal crystal protein was confirmed by Western blot analysis and bioassay against the larvae of Hyphantria cunea (Lepidoptera： Arctiidae) and Plutella xylostella (Lepidoptera：Plutellidae).

• Journal of Microbiology and Biotechnology
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• v.9 no.2
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• pp.132-139
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• 1999

A cell-entrapment technique using compressed air was applied to Bifidobacterium longum KCTC 3128 for the improvement of bifidobacteria viability. The main cell-entrapment matrix used was alginate, and viability improvement of the B. longum entrapped in alginate lattices was monitored along with the effects of other additional biopolymers. A prerequisite for acquiring consistent results was the uniformity of bead size and cell distribution which was achieved by using compressed air and mixing the cell suspension with sterilized alginate powder, respectively. The viability losses of the B. longum entrapped in alginate beads in the presence of three different substances logarithmically increased in relation to the reaction time, and proportionately decreased with an increased alginate concentration and bead diameter. The strongest improvement in B. longum viability was exhibited with a bead containing 3％ alginate and 0.15％ xanthan gum.

• Journal of Environmental Health Sciences
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• v.26 no.2
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• pp.91-96
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• 2000

We investigated characters of transdermal therapeutic system(TTS) and the skin permeability of that with applying drug delivery system(DDS). Natural gums were selected as material of TTS. The permeation of natural gums ointment containing drug in rat skin using diffusion cell model. Permeation properties of materials were investigated for water soluble drug such as riboflavin in vitro. We used glycerin, PEG 600 and oleic acid as enhancers. Since dermis has more hydration than the stratum corneum, skin permeation rate at steady state was highly influenced when glycerin was used in riboflavin. The permeation rate of content enhancer and drug was found to be faster than that of content riboflavin only. These results showed that skin permeation rate of drug across the composite was mainly dependent on the property of ointment base and drug. All the gum ointment tested showed good safety. Proper selection of the materials which resemble and enhance properties of the delivering drug was found to be important in controlling the skin permeation rate.

• KSBB Journal
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• v.5 no.1
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• pp.37-42
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• 1990

In on-line measurement, there were two difficult problems to remove the biomass in the sample and to prevent the contamination at the sampling. In this study, the problem of the contamination at the sampling was solved by using the sampling device consisting of sterilizable sampling line, peristaltic pump and three-way valve. The glucose concentration was measured by glucose calibration equation without removing the biomass. Xanthan fermentation was performed satisfactorily using this automatic analyzing device.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.3
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• pp.251-257
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• 2000

District heating and cooling systems offer highly efficient energy utilization and maintenance by centralizing heat management. More pumping power, however, is required because the water has to travel long distance from heat source to the users. In the present study, a trace of drag reduction additives is added to the District Cooling system to achieve a significant drag reduction and save pumping power. Water-soluble polymers, surfactants, and environment-friendly degradable polymers are used as effective drag reducing additives. Time dependent percent drag reductions are compared for various additive solutions at 100 wppm concentration for different water velocity. Without as an anionic surfactant, copolymer was most effective in percent drag reduction. It is found that there exists an optimal condition when copolymer is mixed with SDS. An environment-friendly degradable polymer, xanthan gum, is found to be a significant drag reduction additive. Ice slurry systems, can give less pressure drops compared with chilled water system for certain condtions. Drag reduction additives were also effective for the ice slurry system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.5
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• pp.770-774
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• 2002

The effect of mixing ratio of materials and their retort processing conditions on the physical properties and preference of oyster porridge were investigated. Rice gave adequate viscosity (about 800 cp) to the porridge as it was used 10～12% level and half of it was ground. Potato starch, waxy corn starch, and Perfectamyl AC showed small variation in viscosity unrelated to the temperature, that was a good condition for high quality porridge. Especially, waxy corn starch had a good property for retort porridge because its viscosity was maintained high during the processing and decreased to preferable one after processing. Purity CSC, modified starch gave gum-like texture and didn't cause water-separation much after freezing and thawing treatment of the porridge. Therefore, it was good for enhancing the physical property of the porridge as a co-additive of waxy corn starch when it was used at quarter level of waxy corn starch. Xanthan gum increased dispersibility of materials and it was useful for stabilizing physical quality of the porridge without affecting preference when it was used below 0.2% concentration. As a result, the optimal material-mixing ratio was determined as rice 10% (50% of it was ground), waxy corn starch 1.5%, Purity CSC 0.5%, xmthan gum 0.2%, salt 0.3%, and water 87.5%. Oyster's porridge, retort processed with this recipe, showed stable physical property after 6 month storage at room temperature.

• Journal of Nutrition and Health
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• v.16 no.3
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• pp.146-153
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• 1983

In this study, buckwheat four was classified by the order of extraction from the inmost layer to the outmost layer, and was designated as $B_1,\;B_2,\;B_3,$ and the mixed flour of $B_1,\;B_2,\;B_3$ (1:1:1) was named $B_0$. To improve the dried noodle-making properties, various levels of strong wheat flour and additives such as sodium alginate (SA) and xanthan gum(XG) were added to buckwheat. 1) The buckwheat $B_2$ and $B_3$ flours contained much higher amounts of crude ash, protein and fat than the $B_1$ flour. 2) Buckwheat $B_3$ flour demonstrated lower maxium viscosity value by amylograph than the $B_1$ flour, but it demonstrated 2 times higher maximum viscosity value than wheat flour. Buckwheat $B_1$ flour demonstrated 4-5 times higher maximum viscosity value than wheat flour. Addition of SA and XG increased the viscosity of the flour mixtures. 3) It was possible to make dried noodles from the composite flour of (buckwheat 40 %+wheat 60 %). The lesser the quantity of buckwheat flour was, the better the kneading property of mixed flour was. 4) SA and XG, which were added at the level of 1.0-1.5%, significantly improved dough making properties and the cooking quality of the noodles.

• Journal of Microbiology and Biotechnology
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• v.8 no.2
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• pp.171-177
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• 1998

The strain A49, which produces a new type of extracellular polysaccharide was isolated from soil samples. From morphological, physiological and biochemical tests, the strain A49 was identified as a Bacillus polymyxa and named Bacillus polymyxa A49. Bacillus polymyxa A49 was found to produce a highly viscous extracellular polysaccharide when grown aerobically in a medium containing glucose as the sole source of carbon. The polysaccharide (A49 POL) showed a homogeneous pattern on gel permeation chromatography (GPC) and its molecular weight was estimated to be about 1.6 mega dalton (mDa). The FT-IR spectrum of A49-POL revealed typical characteristics of polysaccharides. As a result of investigations with HPLC and carbozole assay, A49-POL was found to consist of L-fucose, D-galactose, D-glucose, D-mannose, and D-glucuronic acid, with the molar ratio of these sugars being approximately 1:2:7:50:12. Rheological analysis of A49 POL revealed that it is pseudoplastic and has a higher apparent viscosity at dilute concentrations than does xanthan gum. The consistancy factor of A49 POL was found to be higher, and the flow index of A49 POL lower, than xanthan gum. Its apparent viscosity was comparatively unstable at various temperatures. the A49 POL showed the highest apparent viscosity at pH 3. When salts were added to A49 POL solution, the solution was compatible with up to 10% KCl, 35% NaCl, 55% $CaCl_2$, 55% $MgCl_2$, 55% $K_2HPO_4$, and 110% $Ca({NO_3})_2$, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.9
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• pp.1253-1257
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• 2009

The effects of seven commercial gums (xanthan gum, guar gum, pectin, gum arabic, gellan, locust bean gum, and sodium alginate) at different concentrations (0, 0.3, and 0.6%) on flow properties of sweet potato starch (SPS) pastes were investigated. Flow behavior characteristics were adequately described by power law flow model, and yield stress was also measured by vane method. SPS-gum mixtures (5% w/w) at $25^{\circ}C$ were found to have high shear-thinning flow behavior with yield stress, and their consistency index (K) and apparent viscosity ($\eta_{a,100}$) increased with elevated gum concentration, except for pectin and sodium alginate. Vane yield stress ($\sigma_o$) value of SPS-pectin mixture was lower when compared to other mixtures while that of SPS-gellan mixture was much higher. Most of the gums, except for pectin, gum arabic, and sodium alginate, showed a synergistic effect on the elastic properties of SPS-gum mixtures. In general, the flow properties of SPS-gum mixtures appeared to be strongly influenced by the addition of gum, and dependent on the type and concentration of gum.

• Ecology and Resilient Infrastructure
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• v.5 no.3
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• pp.180-188
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• 2018

Biopolymer based on microbial ${\beta}$-glucan and xanthan gum is a rising geotechnical material that can enhance the cohesion between soil particles and consequently reduce soil erosion. Recently, biopolymer is proposed to utilize for the riverbank strengthening. As an effort of the ecological assessment of biopolymer application in civil engineering, this study examined the effects of biopolymer on seed germination and growth of nine plant species inhabiting in the Korean riverside. Responses of above-ground growth to the biopolymer differed among plant species. One species grew less but others maintained their growth when plants were grown in the soil with biopolymer. In contrast, root grew more vigorously and root/shoot ratio decreased in the biopolymer across testing plant species. These results indicate that biopolymer application on the river bank likely stimulate root growth of native plant species, which, in turn, possibly reinforces riverbank. Species specific responses of above-ground growth implies that ecological effects of biopolymer application would depend on the species composition of the ecosystem.