• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.10
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• pp.1341-1350
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• 2007

This study was designed to ultimately develop a highly efficient mass production technology of bacterial cellulose isolated from the citrus gel fermented by G. hansenii TL-2C. Pilot equipment made with FRP vessel length (665 mm) ${\times}$ width (375 mm) ${\times}$ height (210 mm) was developed for mass production of the citrus gel. To develop the optimal conditions for mass production of citrus gel, comprised of citrus juice (6,000 mL) diluted 100 times, containing 5% seed bacteria, 10% sucrose, and 1% ethanol, citrus juice was fermented at $30^{\circ}C$ for 14 days, and gel productivity in pilot system was examined. BC was isolated and purified from the citrus gel, and their chemical composition and physicochemical properties were investigated.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.170-175
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• 2004

This study was conducted to determine the minimum concentration of citrus juice for basal medium and also to search for an additional carbon source for the best production of the gel. A concentrate of citrus fruit juice of 65$^{\circ}$Brix, it was diluted to be used as a basal medium. Static cultivation of Gluconacetobacter hansenii TL-2C for 14 days at 3$0^{\circ}C$ produced the best gel with 7.5$\pm$0.4 mm thickness in the 6-fold diluted citrus Juice concentrate without any additional nutrient. However, the same thickness could be obtained with 60 to 100-fold diluted juice concentrate when refined white sugar was added at appropriate concentrations. Glucose was the most effective sugar for the both of gel and acid production, and optimal concentration of the sugar was 10$^{\circ}$Brix. Ethyl alcohol at 1.0% had synergistic effects in combination with refined sugar and increased the gel thickness up to 15.1 mm which was 1.85 times thicker than that of refined sugar alone. However, acetic acid was not effective. Gel productivity with supplement of ethanol was 172.6$\pm$8.4 g wet/L, and it was approximately equal to 4.7 g of dry gel/L.

• Journal of Radiation Industry
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• v.5 no.2
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• pp.113-118
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• 2011

Hydrogels from a mixture of poly(N-vinylpyrrolidone) (PVP), ${\kappa}$-carrageenan and microorganism fermentation celluose were prepared by $^{60}Co$ gamma-ray irradiation. PVP and ${\kappa}$-carrageenan were mixed with the different ratios. Microorganism fermentation celluose were added to the mixture of PVP and ${\kappa}$-carrageenan to evaluate the effect of microorganism fermentation celluose on the gel strength. The gel strength of the hydrogel was evaluated for application of a wound dressing. The results showed that gelation and gel strength were increased with increasing the content of the microorganism fermentation celluose.

• The Plant Pathology Journal
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• v.34 no.6
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• pp.499-505
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• 2018

Huanglongbing (HLB, Citrus greening disease) is one of the most devastating diseases that threaten citrus production worldwide. Although HLB presents systemically, low titer and uneven distribution of these bacteria within infected plants can make reliable detection difficult. It was known loop-mediated isothermal amplification (LAMP) method has the advantages of being highly specific, rapid, efficient, and laborsaving for detection of plant pathogens. We developed a new LAMP method targeting gene contained tandem repeat for more rapid and sensitive detection of Candidatus Liberibacter asiaticus (CLas), putative causal agent of the citrus huanglongbing. This new LAMP method was 10 folds more sensitive than conventional PCR in detecting the HLB pathogen and similar to that of real-time PCR in visual detection assay by adding SYBR Green I to mixture and 1% agarose gel electrophoresis. Positive reactions were achieved in reaction temperature 57, 60 and $62^{\circ}C$ but not $65^{\circ}C$. Although this LAMP method was not more sensitive than real-time PCR, it does not require a thermocycler for amplification or agarose gel electrophoresis for resolution. Thus, we expect that this LAMP method shows strong promise as a reliable, rapid, and cost-effective method of detecting the CLas in citrus and can be applied for rapid diagnosis is needed.

• Journal of Radiation Industry
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• v.4 no.4
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• pp.365-372
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• 2010

Irradiation has been recognized as a highly suitable tool to aid in the formation of hydrogel. The radiation process has various advantage, such as easy process control and the lack of necessity for initiators and crosslinker. In this study, the hydrogel containing the citrus fermentation gel for the wound healing were successfully synthesized. The strength of hydrogel was increased as a function of a increasing the concentration of citrus and the irradiation doses. In addition, this hydrogel have been evaluated by the cytotoxicity and animal experiment.

• Journal of Radiation Industry
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• v.4 no.4
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• pp.373-379
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• 2010

Cellulose, chitin, chitosan and hyaluronic acid are well known as polysaccharides. These polysaccharides have many effects on cell growth and differentiation. Cell activation increases with increasing the polysaccharides concentration. In this study, gelatin scaffold containing microorganism fermented cellulose, citrus gel were prepared by using irradiation technique. Physical properties of the scaffolds were investigated as a function of the concentrations of gelatin and citrus gel and the cell attachment, cell morphology and inflammation of the scaffolds also were characterized for regeneration of skin tissue.

• Korean Journal of Food Science and Technology
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• v.14 no.1
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• pp.63-66
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• 1982

The pectin content in tangerine peel and the characteristics of extracted pectin and its gel were determined. The pectin contents of citrus peel and citrus albedo were 11.52% and 9.3% on a dry weight basis, respectively The equivalent weight, methoxyl content and acetyl content of the extracted citrus peel pectin were 596, 13.41% and 0.125% respectively. The intrinsic viscosity and molecular weight of extracted citrus peel pectin were higher than those of commercial citrus pectin samples. The anhydrouronic acid content and jelly grade of the extracted pectins were 98.4% and 138.1, respectively. These were higher than those of commercial citrus pectin. In the textural characteristics of gels, the gel made from the extracted pectin was shown to have lower values in hardness, cohesiveness, adhesiveness and gumminess than the gels made from commercial citrus pectins.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.176-181
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• 2004

Gluconacetobacter hansenii TF-2, an isolate from black tea fungus, was statically cultivated to ferment cellulose gel from citrus juice. The juice prepared by press filtering of peeled citrus fruit contained 135.5 mg of total sugar/mL, 1.23% of total acid, and average pH of the juice was 3.98. The bacterium produced cellulose gel optimally on the surface of culture broth containing 17% of citrus juice and 10$^{\circ}$Brix of total sugar. The optimum temperature was 3$0^{\circ}C$ for producing acetic acid and gel formation. The bacterium could not produce acetic acid on gel formation at 4$0^{\circ}C$. The optimum pH was 3.0∼4.0 but was not significantly different between pH 3.0∼4.0. The cultivation for 18 days under optimal conditions produced gel as 14.2$\pm$0.6 mm of thickness and acids equivalent to 1.90$\pm$0.22% of acetic acid. The pH of culture broth was stabilized at 2.6∼2.8 during the cultivation. Remaining sugar content was 27.1$\pm$4.2 mg/mL of total sugar and 6.9 mg/mL of reducing sugar. The gel productivity was 137.8$\pm$9.7 g/L.

• Parasites, Hosts and Diseases
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• v.52 no.1
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• pp.117-120
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• 2014

Several studies have reported that the citrus red mites Panonychus citri were an important allergen of citrus-cultivating farmers in Jeju Island. The aim of the present study was to purify and assess properties of a cysteine protease from the mites acting as a potentially pathogenic factor to citrus-cultivating farmers. A cysteine protease was purified using column chromatography of Mono Q anion exchanger and Superdex 200 HR gel filtration. It was estimated to be 46 kDa by gel filtration column chromatography and consisted of 2 polypeptides, at least. Cysteine protease inhibitors, such as trans poxy-succinyl-L-leucyl-amido (4-guanidino) butane (E-64) and iodoacetic acid (IAA) totally inhibited the enzyme activities, whereas serine or metalloprotease inhibitors did not affect the activities. In addition, the purified enzyme degraded human IgG, collagen, and fibronectin, but not egg albumin. From these results, the cysteine protease of the mites might be involved in the pathogenesis such as tissue destruction and penetration instead of nutrient digestion.

• Korean Journal of Environmental Agriculture
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• v.23 no.4
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• pp.245-250
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• 2004

An analytical method was developed to determine monocrotophos residues in apple, citrus, and soil using high-performance liquid chromatography (HPLC) with ultraviolet absorption detection. Monocrotophos was extracted with acetone from apple, citrus and moist soil samples. The extract was concentrated, added with saline water, and subjected to n-hexane washing to remove nonpolar co-extractives. Dichloromethane partition was then followed to recover monocrotophos from the aqueous phase. Silica gel column chromatography was employed to further purify the extract prior to HPLC determination. Reverse-phase HPLC using an oct-adecylsilyl column was successfully applied to separate and quantitate the monocrotophos residue in sample extracts at the wavelength of 230 nm. Overall recoveries of monocrotophos from fortified samples averaged $95.3{\pm}2.1%$ (n=6), $970{\pm}0.7%$ (n=6), and $92.8{\pm}4.3%$ (n=12) for apple, citrus, and soil, respectively. The proposed method was quite reproducible and sensitive enough to replace the troublesome gas-liquid chromatographic analysis for monocrotophos residues.