• Microbiology and Biotechnology Letters
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• v.31 no.3
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• pp.250-256
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• 2003

Lactic acid bacteria with amylolytic and acid producing activities can ferment starch directly to lactic acid thereby producing a monomer for the production of biodegradable poly lactic acid (PLA). In this study, the strain producing L-lactic acid from soluble starch was isolated from Nuruk. The isolated strain was identified as Enterococcus sp. through its morphological, cultural, biochemical characteristics as well as the 16S rDNA sequence analysis, and named Enterococcus sp. JA-27. Enterococcus sp. JA-27 produced exclusively L-lactic acid from soluble starch as a carbon source. The optimal conditions for the maximum production of L-lactic acid from Enterococcus sp. JA-27 were 30 C, pH 8, 1.5 % soluble starch as a substrate and 3.5 % tryptone as a nitrogen source, 0.1 % $K_2$$HPO_4$, 0.04 % $MgSO_4$. $7H_2$O, 0.014 % $MnSO_4$$.$4$H_2O$, 0.004% $FeSO_4$$.$$7H_2$O. Batch and fed batch culture were carried out and the former was more effective. L-Lactic acid production in the optimum medium was significantly increased in a 7 L jar fermenter, where the maximum L-lactic acid concentration was 3 g/L. For the purification of lactic acid in fermented broth, two stage ionexchange column chromatographies were employed and finally identified by HPLC.

• Microbiology and Biotechnology Letters
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• v.39 no.4
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• pp.324-329
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• 2011

Eight endophytic fungal strains were isolated from the roots of Calystegia soldanella from the western coast of South Korea. The culture filtrate of the eight endophytic fungi were applied to waito-c rice seedlings in order to verify potential plant growth promotion activities. The results of bioassay indicated that the Cs-9-7 fungal strain possessed the highest plant growth promotion activity. Fungal culture filtrates were analyzed to verify secondary metabolites using gas chromatography and mass spectroscopy with selected ion monitoring (GC/MS-SIM). The culture filtrate of the Cs-9-7 fungal strain was confirmed to contain gibberellins GA3 (1.229 ng/mL), GA4 (3.535 ng/mL), GA7 (1.408 ng/mL) and GA12 (0.378 ng/mL). Polymerase chain reactions (PCR) were performed so as to determine the internal transcribed spacer (ITS) regions for the identification of isolated strains with universal primers ITS-1 and ITS-4. The Cs-9-7 fungal strain, isolated from the root of C. soldanella, has been named Aspergillus tubingensis Cs-9-7.

• Journal of Conservation Science
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• v.25 no.4
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• pp.399-409
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• 2009

Outdoor iron artefacts are easily corroded by affection of environmental pollutants directly. Especially they need to be removed $Cl^-$ ions, but outdoor iron artefacts are excluded for desalination owing to their special features. Therefore this study contains the conservation processes of an iron stele of the Joseon Dynasty as the sample as well as desalination experiments that were carried out the desalting method using spill pads and the immersion desalting method together in order to compare. Desalting methods were compared by analyses such as an optical and metallurgical microscope, SEM-EDS, pH meter, Ion Chromatography and X-ray diffraction. As a result of the analysis, the optical and metallurgical microscopy show that the corrosion products are constituted by the layers and the metallurgical microstructure is a white cast iron. The SEM-EDS results of corrosion products detected mainly Fe, O, and especially Cl upto 2.48wt%. The results of pH and anion analysis for the washing solution, the desalting method using spill pads shows the similar effect to the immersion desalting method. As a result of XRD analysis before and after desalting corrosion products, goethite, magnetite, lepidocrocite and akaganeite are detected before desalting, but akaganeite is not detected after desalting at the desalting methode using spill pads, which indicates to have an effect on desalination. Therefore the results show that the desalting method using spill pads has an effect on desalination similar to the immersing desalting method.

• Applied Biological Chemistry
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• v.46 no.2
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• pp.79-83
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• 2003

Elicitins, proteinaceous elicitors secreted from Oomycetes fungi (Phytophthora spp. and Pythium spp.), have been known as inducer of hypersensitive response (HR) in incompatible interactions between plant and pathogens. Five elicitins among many Korean Phytophthora species caused the reactions of distal HR in radish, chinese cabbage and some hot pepper cultivars, but not in cucumber and tomato. Because the isolation of elicitin from Phytophthora cambivora hasn't been reported yet, we have purified a cambivorein, a new member of the elicitin family, from the culture filtrate of Phytophtilora cambivora (KACC 40160) by using FPLC (Fast Protein Liquid Chromatography, AKTA) with sepharose S and Sephacryl HR columns. We confirmed that it induces necrosis activities in some hot pepper cultivars and its molecular weight is about 10 KDa by Tricine-SDS-PAGE. Comparison of amino acid sequences of its N-terminal ends also informed the identification of Iysine at the 13th position, which is characteristic of a kind of basic elicitin isoform $({\beta}-isoform)$. It Also showed that our elicitin is not identical with N-terminal sequences of many elicitins reported from Phytophthora spp..

• Journal of Applied Biological Chemistry
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• v.61 no.2
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• pp.109-117
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• 2018

Recently, cancer incidence in modern society is increasing sharply. DNA damage is caused by intrinsic or extrinsic factors in the human body, cells protect themselves by defense mechanism against DNA damage. Also, Aberrant DNA and deficient DNA repair are closely associated with various diseases, including aging and cancer. Researchers are interested in search for proper materials to inhibition for DNA damage. As knew the side effects of synthetic antioxidant, some researches have been conducted about cancer prevention materials derived from nature. Root of Smilax china, in Liliaceae, is used detoxification and tumor treatments traditionally. However, studies on the inhibitory effect of DNA damage haven't progressed. In this study, antioxidant activity and protective effects on oxidative DNA damage of S. china root were confirmed, relationship between those activities and contents of phenolic compounds in plants were established. S. china root effectively removed 1,1-diphenyl-2-picryl-hydrazyl radicals and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid radicals. The quantification and identification of phenolic compounds were confirmed by high performance liquid chromatography analysis, its antioxidant activity was associated with some phenolic compounds. In addition, protective effects against hydroxyl radicals and ferrous ion-induced oxidative DNA damage were confirmed in plasmid DNA. In the cellular levels, S. china root suppressed the expression of ${\gamma}$-H2AX and p53 protein in NIH 3T3. Besides, S. china root suppressed H2AX and p53 mRNA levels. In conclusion, S. china root had the effect on DNA protection and antioxidant.

• The Korean Journal of Pesticide Science
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• v.4 no.1
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• pp.1-10
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• 2000

The purpose of this study is to establish the assessment techniques of hazardous chemicals by the development of analytical method of biological samples. In this study, we have developed an extraction method of nine pesticides used for rice paddy that resulted in high recovery from the spiked human urine by the liquid-liquid extraction with diethyl ether at pH 7.0. Calibration curve obtained from each pesticide standard using by gas chromatography/mass spectrometry/selected ion monitoring has shown good linearity and detection limits were the range of $0.4{\sim}2.0$ ng/mL in urine. As a biological monitoring, urine samples of local farmers exposed directly to nine pesticides in the field were collected and analyzed by GC/MS. Of the tested pesticides, metabolites of phenthoate assumed were identified by GC/MS analysis. No parent compound was detected.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.321-329
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• 2014

This experiment was conducted to establish an analytical method for residues of amisulbrom, as recently developed an oomycete-specific fungicide showing inhibition of fungal respiration, in crops using HPLC-UVD/MS. Amisulbrom residue was extracted with acetonitrile from representative samples of five raw products which comprised apple, green pepper, kimchi cabbage, potato and hulled rice. The extract was diluted with 50 mL of saline water and directly partitioned into dichloromethane to remove polar co-extractives in the aqueous phase. For the hulled rice sample, n-hexane/acetonitrile partition was additionally employed to remove non-polar lipids. The extract was finally purified by optimized Florisil column chromatography. On an octadecylsilyl column in HPLC, amisulbrom was successfully separated from sample co-extractives and sensitively quantitated by ultraviolet absorption at 255 nm with no interference. Accuracy and precision of the proposed method was validated by the recovery test on every crop samples fortified with amisulbrom at 3 concentration levels per crop in each triplication. Mean recoveries ranged from 85.3% to 105.6% in five representative agricultural commodities. The coefficients of variation were all less than 10%, irrespective of sample types and fortification levels. Limit of quantitation (LOQ) of amisulbrom was 0.04 mg/kg as verified by the recovery experiment. A confirmatory method using LC/MS with selected-ion monitoring technique was also provided to clearly identify the suspected residue. The proposed method was sensitive, reproducible and easy-to-operate enough to routinely determine the residue of amisulbrom in agricultural commodities.

• Journal of Food Hygiene and Safety
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• v.23 no.3
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• pp.218-221
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• 2008

The levels of sulfites in wooden chopsticks were analyzed using two different methods, distillation-alkali titration and ion chromatography. According to the two methods, Sulfur dioxide($SO_2$) was validated by 0.6 and 0.2 ${\mu}ml$ of limit of detection(LOD), 1.8 and 0.5 ${\mu}ml$ of limit of quantification, (LOQ) and a $R^2>0.998$ for linearity, respectively. The recoveries of $SO_2$ from food simulants spiked ar levels of 100 ppm were 70.2-100.2%. 158 samples of wooden chopsticks were monitored the migrated amounts of sulfites. Sulfites were detected in 30 samples in ranged of 0.6 to 15.5 ppm. Maximum migration level, 15.5 ppm of sulfites was considered giving no harmful effect to human since it was reached 5.5% of estimated SML.

• Journal of Food Hygiene and Safety
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• v.31 no.6
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• pp.432-438
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• 2016

Ethoxyquin (EQ, 1,2-dihydro-6-ethoxy-2,2,4-trimethyl-quinoline) is quinoline-based antioxidant used in the animal feed and food industry to protect the raw materials and final products against oxidation. In recent years the use of synthetic antioxidants in fishmeal ingredients carry-over to farmed fish fillets has received increasing attention in food safety. This study was conducted to develop an analytical method to determine EQ in aquatic products. The analytes were confirmed and quantified via liquid chromatography-tandem mass spectrometry (LC-MS/MS) in the positive ion mode using multiple reaction monitoring (MRM). The sample was extracted with 1 N HCl (in case of flatfish extracted with 1 N HCl containing 10% acetonitrile). Then, solid phase extraction (SPE) was used for the cleanup. Standard calibration curves presented linearity with the correlation coefficient ($r^2$) > 0.99, analyzed at 0.005-0.2 mg/kg concentration. The developed method was validated according to the Codex Alimentarius Commission (CAC) guideline. The limits of quantitation for EQ were 0.01 mg/kg. Average recoveries ranged from 81.3% to 107%. The repeatability of measurements, expressed as the coefficient of variation (CV, %), was below 10%. The analytical method was characterized with high accuracy and acceptable sensitivity to meet CODEX guideline requirements and would be applicable to analyze the EQ residue in aquatic products.

• Korean Journal of Food Science and Technology
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• v.43 no.5
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• pp.532-536
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• 2011

The internal standard method using ion chromatography combined with tandem mass spectrometry (IC-MS/MS) for quantifying perchlorate in different types of food was established. Because the presence of ions and other biomolecules in matrices usually interrupts accurate determination of perchlorate, it is necessary to develop efficient, reproducible method to determine perchlorate concentrations in food. In this study, the internal standard method was compared with the external standard method to determine perchlorate concentrations in standard samples. The obtained method detection limit (MDL) for perchlorate was 0.005 ${\mu}g/L$ for bottled water, 0.12 ${\mu}g/L$ for milk, 0.27 ${\mu}g/kg$ for rice, 0.16 ${\mu}g/kg$ for vegetables, and 0.07 ${\mu}g/kg$ for seaweed, respectively. The limit of quantitation (LOQ) was calculated by multiplying the MDL by 7. The recoveries of perchlorate from food samples spiked with perchlorate ranged from 98 to 105% and their percent relative standard deviation (%RSD) levels were <20%. This method was successfully applied for the quantitative determination of perchlorate in various kinds of food.