• Journal of Korea Water Resources Association
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• v.57 no.2
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• pp.111-125
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• 2024

The study has examined alterations in groundwater quality by investigating the influence of rainfall on electrical conductivity (EC) and nitrate concentration in the groundwater of the Geum River Basin in South Korea. Mann Kendall and Sen's Slope estimator were employed to analyze the trends and estimate the trend's magnitude. The administrative map of the study area was utilized to assess the trends of these parameters within each administrative region. Seventeen years (from 2005 to 2021) of data on EC, groundwater levels (GWL), precipitation, and six years (from 2015 to 2020) of nitrate concentration data were utilized for this analysis. The results indicate that, in most administrative regions, there has been an increase in nitrate concentration, and EC, whereas precipitation has seen a slight decrease in a downstream and an increasing trend in upstream. The correlation coefficients calculated between these parameters reveal that there is no direct impact of precipitation on nitrate and EC, but a negative correlation was observed between GWL and EC. The most significant increasing trend in nitrate concentration was observed in two districts (Iksan and Gunsan ), which correspond to regions with significant agricultural activity; about 50% of these districts area are used for agricultural activities.

• Journal of Microbiology and Biotechnology
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• v.34 no.2
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• pp.457-466
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• 2024

Cellobiose dehydrogenases (CDHs) are a group of enzymes belonging to the hemoflavoenzyme group, which are mostly found in fungi. They play an important role in the production of acid sugar. In this research, CDH annotated from the actinobacterium Cellulomonas palmilytica EW123 (CpCDH) was cloned and characterized. The CpCDH exhibited a domain architecture resembling class-I CDH found in Basidiomycota. The cytochrome c and flavin-containing dehydrogenase domains in CpCDH showed an extra-long evolutionary distance compared to fungal CDH. The amino acid sequence of CpCDH revealed conservative catalytic amino acids and a distinct flavin adenine dinucleotide region specific to CDH, setting it apart from closely related sequences. The physicochemical properties of CpCDH displayed optimal pH conditions similar to those of CDHs but differed in terms of optimal temperature. The CpCDH displayed excellent enzymatic activity at low temperatures (below 30℃), unlike other CDHs. Moreover, CpCDH showed the highest substrate specificity for disaccharides such as cellobiose and lactose, which contain a glucose molecule at the non-reducing end. The catalytic efficiency of CpCDH for cellobiose and lactose were 2.05 × 10⁵ and 9.06 × 10⁴ (M^-1 s^-1), respectively. The result from the Fourier-transform infrared spectroscopy (FT-IR) spectra confirmed the presence of cellobionic and lactobionic acids as the oxidative products of CpCDH. This study establishes CpCDH as a novel and attractive bacterial CDH, representing the first report of its kind in the Cellulomonas genus.

• Journal of Korean Academy of Nursing
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• v.28 no.2
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• pp.479-489
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• 1998

This work was done for 9 patients having experience of a herb medical treatment after being diagnosed as CVA during a year from January, 1996 to December, 1996 by using an ethnographic research method. The summarized results of this research are following. Ⅰ. THE EXPERIENCE OF THE ILLNESS First, the falling-ill phase is the time that they have the first stroke of paralysis and the decision pattern of medical institution' comes out. The emotional experience in the period is something like 'flustration', 'anxiety', 'despair', and 'expectation'. Second, the active-treatment phase is the time that the patients as well as their family or care giver not only show the positive attitude and actively participate in the illness treatment but also show a lot of interest in medical institutions and activities of health recovery. There is a primary factor of the continuation of treatment as an experience of treatment and being crushed and sensitivity as an experience of the illness. Third, the rehabilitation phase is the time that the patients or their family become tired and insensitive to the treatment and recuperation, and then reduce the treatment activity. There is a primary influence factor of the discontinuance of treatment as an experience of treatment and physical experience and emotional experience as an experience of the illness. The physical experience is divided into 'personal-hygiene care', and 'the sphere of activity' The emotional experiences are 'blaming someone', 'contempt' and 'despair' as a negative experience and 'hope' as a positive experience. Ⅱ. COPING STRATEGY There are a physical coping, an emotional and mental coping, a social coping, and a spiritual coping as a coping strategy used for the patients to overcome their illness and adjust themselves to their altered life. First, the physical coping comes out as 8 categories, 'using an auxiliary tool', 'doing exercise', 'protecting', 'improving their diet', 'taking care of something', 'using subsidiary medicines', 'trying a folk remedy', and 'having interest in their health'. Second, for the emotional and mental coping, there are 'accepting' and 'trying' as a positive coping and a failure of control as a negative coping. Third, the social coping is appeared as 'being supported'. Fourth, the spiritual coping is recognized as' recourse to God' and 'preparation of death'. After all, the elderly CVA patients in an agricultural area choose the act of treatment based on the traditional belief and the relationship with a caretaker. A personal health can be maintained by taking care of themselves and controling their mind, and the overcome of the illness is decided on the basis of traditional concepts and cultural principles in which the patients as well as the family, neigbors and take carers should work out together and cooperate with each other in order to achieve that.

• Current Research on Agriculture and Life Sciences
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• v.33 no.2
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• pp.49-56
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• 2015

The aim of this research was to investigate the anti-oxidantive activities of extracts from Chionanthus retusus leaves, fruits and flower. The content of phenolics were 20.8 mg/g in water extracts and 32.2 mg/g in 90% ethanol extracts from flower. The DPPH free radical scavenging activity of extracts from Chionanthus retusus was above 70% at phenolic concentration $100{\mu}g/mL$. The ABTS radical decolorization activities of water and ethanol extracts were both above 80% at $100{\mu}g/mL$ phenolic concentration, respectively. The antioxidant protection factor(PF) of water and 80% ethanol extracts from leaves was the highest as 2.27 PF and 1.70 PF at $50{\mu}g/mL$ phenolic concentration. The TBARs inhibition rate of the Chionanthus retusus extracts, was above 70% at $200{\mu}g/mL$ phenolic concentration. The anti-oxidantive activities of extracts from leaves were shown more active than BHT as a positive control except TBARs. These results confirmed that the extracts from Chionanthus retusus leaves, fruits and flower was shown the high anti-oxidant activity. The results can be expected isolated phenolic compounds from Chionanthus retusus to use as functional beauty food resource.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.12
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• pp.1609-1614
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• 2008

To provide scientific information for processing of value-added products from onion, volatile flavor compounds were compared in onions harvested in 6 regions, such as Muan (Jeonnam), Buan (Jeonbuk), Andong (Gyeongbuk), and 3 regions of Gyeongnam around Changnyeong (Yueo, Jangma, Seongsan). A total of 51 compounds were detected in samples by solid phase microextraction (SPME)/GC/MSD and they consisted mainly of sulfur-containing compounds (20), aldehydes (4), ketones (5), esters (11), aromatic hydrocarbons (4), nitrogen containing compounds (2), and miscellaneous compounds (5). The sulfur-containing compounds were the major compounds with ranges of $62.6{\sim}80.3%$ of total volatiles, regardless of harvested regions. The amounts of 5 sulfur containing compounds known as having antioxidant activity (2,4-, 2,5-dimetylthiophene, 2-vinyl-1,3-dithiane, 5-methoxy thiazole, and 3,5-diethyl-1,2,4-trithiolane) were the highest in Andong and followed by Yueo, Jangma, Buan, Seongsan, and Muan. However, onions from Buan region had the highest amounts of 5 sulfur-containing compounds known as having anticarcinogenic activity ((Z)-, (E)-methyl propenyl disulfide, (Z)-, (E)-propenyl propyl disulfide, and di-2-propenyl disulfide), followed by Yueo, Andong, Jangma, Seongsan, and Muan.

• Korean Journal of Environmental Agriculture
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• v.33 no.4
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• pp.282-289
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• 2014

BACKGROUND: Methane($CH_4$) is considered as the secondmost potent greenhouse gas after carbon dioxide ($CO_2$). Methanogenesis is an enzyme-mediated multi-step process by methanogens. In the penultimate step, methylated Co-M is reduced by methyl Co-M reductase (MCR) to $CH_4$ involving a nickel-containing cofactor F430. The activity of MCR enzyme is dependent on the F430 and therefore, the bioavailability of Ni to methanogens is expected to influence MCR activity and $CH_4$ production in soil. In this study, different doses of EDTA(Ethylene Diamine Tetraacetic Acid) were applied in flooded soils to evaluate their suppression effect on methane production by chelating Ni of methanogenesis cofactor. METHODS AND RESULTS: EDTA was selected as chelating agents and added into wetland and rice paddy soil at the rates of 0, 25, 50, 75, and $100mmol\;kg^{-1}$ before 4-weeks incubation test. During the incubation, cumulative $CH_4$ production patterns were characterized. At the end of the experiment, soil samples were removed from their jars to analyze total soil Ni and water-soluble Ni content and methanogen abundance. Methane production from 100 mmol application decreased by 55 and 78% in both soils compared to that from 0 mmol. With increasing application rate of EDTA in both soils, water-soluble Ni concentration significantly increased, but total soil Ni and methanogen activities showed negative relationship during incubation test. CONCLUSION: The decrease in methane production with EDTA application was caused by chelating Ni of coenzyme F430 and inhibiting methanogenesis by methyl coenzyme M reductase. Consequently, EDTA application decreased uptake of Ni into methanogen, subsequently inhibited methanogen activities and reduced methane production in flooded soils.

• The Korean Journal of Mycology
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• v.47 no.4
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• pp.417-425
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• 2019

Biocontrol agents (BCAs) are widely used to protect plants from diverse biotic and abiotic stresses in agricultural and ecological fields. Among the various microbes, many subspecies of the gram-positive genus, Bacillus, have been successfully industrialized as eco-friendly biological pesticides and fertilizers. In the current study, we demonstrated that Bacillus thuringiensis C25 exhibited antagonistic effects on the mycelial growth of Rosellinia necatrix, a fungal phytopathogen. Scanning electron microscopy analysis revealed that B. thuringiensis C25 degraded the cell wall structures of R. necatrix mycelia. In the functional genomic analysis of B. thuringiensis C25, we annotated 5,683 genes and selected the gene sets that potentially encoded fungal cell wall degrading enzymes (CWDEs). The growth inhibition effects on R. necatrix were highly correlated with the transcriptional activity of the mycelial cell wall degrading genes of B. thuringiensis C25. The transcript levels of CWDEs, including CshiA, B, and Glycos_transf_2 genes in B. thuringiensis C25, were enhanced following co-cultivation with R. necatrix. In conclusion, our study suggested that B. thuringiensis C25 could serve as a suitable candidate for controlling R. necatrix and could facilitate elucidating the mechanisms underlying the antifungal activities of BCAs against phytopathogens.

• Journal of Life Science
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• v.17 no.9 s.89
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• pp.1182-1190
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• 2007

The gene encoding for isoamylase of the Pectobacterium carotovorum subsp. carotovorum (Pcc) LY34 was cloned and expressed into Escherichia coli $DH5{\alpha}$. Isoamylase catalyzes the hydrolysis of ${\alpha}-1,6-glycosidic$ linkages specifically in amylopectin, glycogen, and derived oligosaccharides, while the enzyme did not hydrolyze ${\alpha}-1,4-glycosidic$ linkages of amylose. The isoamylase gene (glgX) had an open reading frame of 1,977 bp encoding 658 amino acid residues with a calculated molecular weight of 74,188 Da. The molecular weight of the enzyme was also estimated to be 74 kDa by activity staining of a SDS-PA gel. The mature GlgX had a calculated pI of 4.91. Isoamylase from Pcc LY34 had 70% amino acid identity with isoamylase from Pectobacterium chrysanthemi and contained the four regions conserved among all amylolytic enzymes. The isoamylase was optimally active at pH 7.0 and $40^{\circ}C$. GlgX was $Ca^{2+}-dependent$. The changes of Asp-335, Glu-370, and Asp-442 into Ala, respectively, using site-directed mutagenesis techniques showed that three residues are essential to isolamyalse (GlgX) activity. The sequences around those residues were highly conserved in isoamylase of different origins and GlgX of the glg operon in glycongen biosynthesis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.11
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• pp.1684-1690
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• 2010

The properties of non-waxy rice, Dongjin 1, cultivated with conventional farming (CF) and environmentally-harmonized farming (EHF) using hairy vetch were compared to determine rice water absorption, physicochemical and pasting properties, antioxidant activities of brown and white rice, and a sensory evaluation of cooked white rice was carried out. EHF was treated with green manure crops such as hairy vetch and chitinase, which produce microorganism culture solution. CF was applied with seed disinfection treatments, fertilizer herbicides, and agricultural chemicals for the control of pests and diseases. The absorption level of EHF rice was higher than that of CF rice grain, regardless of the cultivation methods used. The ash and crude lipid contents were higher, but protein and dietary fiber contents were lower in the CF rice than in the EHF rice. The total starch content, water binding capacity, and swelling power of white rice were higher than those of brown rice, regardless of the cultivation methods used. The DPPH's antioxidant activity was shown as follows: EHF brown rice, EHF white rice and CF rice, in a decreasing order. The initial pasting temperature of EHF rice was lower than that of CF rice, but the peak, cold, and breakdown viscosities exhibited reverse trends. The sensory evaluation showed that the cooked white rice cultivated with EHF was not significantly different from that cultivated with CF (p<0.05). The overall preference of cooked rice did not show significant differences between the two cultivation methods (p<0.05).

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.11
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• pp.1627-1633
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• 2010

The purpose of this study is to determine the possibility of Codonopsis lanceolata skin as natural health food source. To accomplish this purpose, the contents of general and antioxidative nutrients of C. lanceolata skin were measured. On a dry weight basis the contents of carbohydrate, crude protein, crude lipid and ash are 24.74, 2.73, 2.96 and 4.84%, and the calories of skin was 266.00 kcal/100 g and total dietary fiber was 64.73%. The contents of essential and non-essential amino acids were 633.40 and 870.72 mg/100 g wet weight basis. The K was the largest mineral followed by Ca, Mg, and P, suggesting that C. lanceolata skin is alkali material. The EDA of water extract from C. lanceolata skin was 18.28~79.30%, and the activity was dependent on the sample concentration. Total phenolic and flavonoids contents of water extract from C. lanceolata skin were estimated as 24.65 and $6.19\;{\mu}g/g$. The C. lanceolata skin extract showed the highest reducing power (3.5) at the concentration of 25 mg/mL. Based on the above results, we deemed that the C. lanceolata skin might have potential antioxidant activities. The general nutrients and antioxidant bioactive materials in C. lanceolata skin were also potential materials for good health food.