• Journal of Korean Society of Environmental Engineers
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• v.27 no.3
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• pp.309-315
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• 2005

In this study, the bacterial regrowth characteristics in drinking water were investigated for various nutrient concentrations and forms using improved BRP method as a traditional approach and specific regrowth rate as a new index. The results of bacterial regrowth potential for glucose and $NH_4^+-N$, which was evaluated by BRP method as a traditional index, appeared to be higher relative to that of acetate or humic acids as carbon source and $NO_2^--N\;or\;NO_3^--N$ as nitrogen sources, respectively. The results obtained by specific regrowth rate as a new index were similar to that of BRP method with respect to the nutrient conditions examined in this study; i.e., the specific regrowth rate for glucose(ranged from 0.005 to $0.082\;hr^{-1}$) was feater than that acetate and humic acids(ranged from 0.005 to $0.068\;hr^{-1}$ and from 0.005 to $0.008\;hr^{-1}$, respectively). And specific regrowth rate for $NH_4^+-N$ (ranged from 0.008 to $0.072\;hr^{-1}$) was feater than that $NO_2^--N\;and\;NO_3^--N$ (ranged from 0.008 to $0.055\;hr^{-1}$ and from 0.008 to $0.059\;hr^{-1}$, respectively). Therefore, specific regrowth rate can be applied in order to evaluate the bacterial regrowth potential in drinking water.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.9
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• pp.659-666
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• 2014

The purpose of this study was to suggest a standard design procedure of landfarming for clean-up of oil-contaminated soils. The standard design procedure consisted of four main phases; soil characterization, determination of contaminated soil volume, determination of nutrient and microbial doses, and estimation of the total remedial period. This study selected standard design parameter values or ranges among various forms used in environmental engineer communities. Those were determination procedures for the contaminated soil volume, the initial contamination concentration and nutrient doses. The suggested standard design procedure were applied for a landfarm design for remediation of a real oil-contaminated site. Soil texture of the site was classified as sandy clay loam and sandy loam. Total nitrogen and total phosphorus were estimated to be 57.01 mg/kg and 83.40 mg/kg, respectively. Also the viable bacterial numbers was assessed to be $1.78{\times}10^4CFU/g$ dry soil. The amount of TPH contaminated soil was estimated to be $4,092m^3$. With the application of remedial factors, it was estimated that the contaminated soil could be treated through 9 batches with a duration of 315 days for a landfarming unit of $15m{\times}40m{\times}1m$. The amount of liquid microorganisms and fertilizers were recommended to be 4,025L and 4,641kg, respectively.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.233-233
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• 2017

Algal communities are important to maintain the aquatic ecosystems function. Algae have short life cycles, they respond quickly to environmental change and their diversity and density can indicate and the quality of their habitat. The bloom forms before the rice seedings have emerged, it may present a physical barrier that prevents the seedlings from penetrating the floodwater. Wind may also move the algal bloom, pushing the young plants beneath the surface. Another harmful action develops when the water dries up and the algae form a layer at the bottom of the field. The layer envelops the seedlings, which are not yet deeply rooted, and drag them to the surface when the water is let in again. Soil utilization pattern can be the mail facter affecting soil physico-chemical properties, especially in soil phosphorus (P). Solid content of the algae culture solution increased with the increase in the nitrogen rather the phosphors concentration. Phosphoric acid was treated with conventional treatments (100-0%, before transplanting time-tillering stage), 50-50%, 0-100%, and un-treated. The herbicide was treated on the 7 DAT (day after transplanting). Green algae samples were collected 20 DAT. Total phosphoric acid was the highest at 0.06 in 50-50% treatment in 20 DAT. The amount of green algae was about twice (9.8 mg/20ml) that of un-treated. Total number of green algae was 54 species(Green algae 35 species, Euglena 9 species, Stone wheel 10 species). Among the phosphoric acid treatment methods, the number of occurrences of green algae were the highest with 39 species in 0-100%, followed by 50-50%, 28 species, conventional treatments, 22 species, non-treatment, 18 species, respectively. Rice Yield was not significantly different by phosphoric treatment time, but slightly higher than un-treated. The maximal algal biomass was observed about 2weeks or 1 month after transplanting; the subsequent decrease of the biomass was related to the consumption by grazers and to a deficient light under the rice canopy. Maximal algal growth was observed just before tillering. To estimate the suitable method of phosphorus application in puddled-soil drill seeding of rice, available phosphorus appearance of algal water bloom, and rice yield were investigated in paddy soil of rice-barley double cropping system.

• Journal of Food Hygiene and Safety
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• v.13 no.2
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• pp.171-187
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• 1998

Garlic occupies a special position among the many foods of vegetable origin because it is the sole food for Koreans during the their lives. And vitamin A has been ingested by forms of food or additives. Cadmium has been described as one of the most dangerous trace elements in the food and environment of man and livestocks. Since the de novo synthesis of stress proteins can be detected early after exposure to some agents, analysis of cadmium-induced changes in gene expression , ie. alterations in patterns of protein synthesis, may be useful to develop as biomarkers of exposure and damage for food hygiene. He acute and chronic combine effects of cadmium (Cd, CdCl2 20mg/kg), garlic oil(Dds: diallyl disulfide 50mg/kg, 3 times a week) and vitamin A(Ra: retinol acetate 50,000 IU/kg, 3 times a week) on Wistar male rats were evaluated concerning cadmium contents, tissues enzyme activity, HSP expression histopathological and electron microscopical examinations. The results of the study are as follows ; 1. Less cadmium was absorbed through the digestive tracts, but the ratio of contents in tissue were not changed by the simultaneous adminstration of diallyl disufide or retinol acetate. 2. ALT(alanine aminotransferase) , AST(aspartate aminotransferase), glucose, BUN (blood urea nitrogen), creatinine, the key indices of the clinical changes in hepatic and renal function were significantly hanged by the cadmium treatment after 1 week in liver, after 4 weeks in kidney. 3. Histopathological changes in cadmium treated rats were appeared at 8 weeks age treatment in kidneys. Homogenous eosinophilic material was accumulated in cortical and collecting tubular lumens at 16 weeks. Degenerated or necrotized tubular cells were observed in cortex and medulla. Degenerated seminiferous tubules and homogeneous eosinophilic material was seen in interstitial tissue of rat treated with cadmium for 16 weeks. Calcium deposits were seen in degenerated seminiferous tubules and the tubules showed severe calcification of rat treated with cadmium for 16 weeks. Electron microscope changes in kidney were observed in rats treated with CdCl2 20 mg/kg. Proximal convoluted tubule cells showed selling of cytoplasm and narrow lumen. Capillary endothelial cells showed cytoplasmic vacuoles and swelling. Degenerated epithelial cells were accumulated in tubular lumen of kidney. 4. Enhanced synthesis of 70 KDa relateve molecular mass proteins were detected in 2 hours after cadmium, exposure, with maximum activity occurring at 8~48 hours. Induction of HSP 70 was evident at proximal tubules and glomeruli in kidney. Testicular cells produced enough HSP to be detected normally. From the above results, it could be concluded that HSP70 induction by the cadmium treatment was a rapid reaction to indicated the exposure of xenobiotics, and retinol acetate reduced the cadmium induced nephrotoxicity.

• Journal of the Korean Chemical Society
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• v.9 no.3
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• pp.128-133
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• 1965

Hydrazonium diphosphate crystallizes with the space-group symmetry $P2_1/C.$ There are two formular units of $N_2H_6H_4(PO_4)_2$ in the unit cell, for which $a = 4.52{\pm}0.02, b = 8.06{\pm}0.03, c = 10.74{\pm}0.03{\AA}\;and\; {\beta} = 100{\pm}0.5^{\circ}.$ The determination of the crystal structure was carried out by means of Patterson, Fourier and difference syntheses. The phosphate group has configuration of nearly regular tetrahedron with the mean P-O distance of $1.55{\AA}.$ The N-N distance found is $1.40{\AA},$ which corresponds to previously reported values for the $N_2H_6^{++} \;ion \;in\; N_2H_6SO_4.$ A molecule has a transform with a center of symmetry in it. Each nitrogen atom forms three hydrogen bonds with the N…O distances 2.62, 2.79 and $2.89{\AA}.$ And a O…O hydrogen bond between different phosphate groups is found with the distance $2.63{\AA}.$ The structure is held together by three-dimensional network of the strong hydrogen bonds.

• The Korean Journal of Mycology
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• v.21 no.2
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• pp.94-105
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• 1993

The genus Cordyceps known as an insect parasite forms a sclerotium in insect bodies and then produces perithecia on the single or multiple stromata produced from sclerotium. Collected Cordyceps were identified into 5 species: Cordyceps militaris, C. nutans, Cordyceps sphecocephala, Isaria japonica, and Torrubiella sp. The fruit bodies of Cordyceps in petri-dish cover were fixed by tape and put the lid on water agar plates to isolate these collected Cordyceps. The germinated spores were transferred from water agar to Potato dextrose agar(PDA) after six hours. Mycelial growth of C. nutans and C. militaris was the most successful on Hamada media and was also good on Complete media and PDA. Mannose as a carbon source was good for two species and Glutamic acid as a nitrogen source was satisfactory to C. militaris and Asparagine gave a good result to C. nutans. C. militaris and C. nutans showed similar mycelial growth rate on the media that contained thiamine-HCI, biotine or nicotinic acid as a vitamine. When conidia of C. nutans were inoculated to insects, mortality was high in Artogeia napi L, Hemiptera, Plutella xylostella and 50% in Orthoptera, 12% in Acantholyda posticalise M, but not Agelastica coerulea B. in Aphididae, C. nutans was collected from only Hemiptera in nature, but killing effect on other insects was proved. Mycelial growth and fruit-body formation were good on the media that consist of rice powder 5g, wheat flour 5g, water 100ml, but formed fruit-body was not complete stromata but a mass of conidia according to results of observing microscope.

• Journal of Korean Ophthalmic Optics Society
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• v.13 no.3
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• pp.103-109
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• 2008

Purpose: This review illustrates an importance of oxidative stress caused by reactive oxygen species (ROS) and reactive nitrogen species (RNS) generation in association with eye disease, especially of cataract, and discusses an important role of lipid peroxide as a mediator of oxidative stress-related ocular dysfunction. Methods: Oxidative stress, resulted from the cellular production of ROS and RNS, is known to cause various forms of cellular damages such as protein oxidation, DNA breaks, apoptosis, and lipid peroxidation. These damages can be developed to human diseases. Accumulating evidence strongly suggests that continuous or constant exposure of eye tissues to oxidative stress is a main cause of cataractogenesis. Therefore, we investigated the action of oxidative stress in ocular dysfunction. Results: The ocular lens is continuously attacked by ROS inevitable generated from the process of cellular metabolism and the chronic exposure to ultraviolet. Excessive generation of ROS, resulting in degradation, oxidation, crosslinking and aggregation of lens proteins, is regarded as an important factor in development of cataract. Conclusions: These oxidative stress and oxidant/antioxidant imbalance produces the excess ROS which can lead to eye dysfunction. Even though known results, it should be noted that there is limited information on the molecular mechanism which can be better defined with the interrelation of oxidative stress and optic abnormalities.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.1
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• pp.71-77
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• 2010

The water fern Azolla belongs to the Azollaceae and forms a symbiotic association with a $N_2$-fixing cyanobacterium, referred to as Anabaena azollae, and this association has currently been demonstrated to have potential as a nitrogen source for rice production. Because of that, Azolla fern has been used not only as organic manure in southern China and northern Vietnam for a long time but also as food for animate creatures in the underwater and decontaminant in the water. However, the phenolic compounds and active materials of Azolla have not been examined in detail in the past studies. In the present study, anti-oxidant ability test and experiment to find a particular active material of Azolla imbricata and Azolla imbricata fraction (AIF) were performed. In anti-oxidant test such as DPPH test and lipoxygenase inhibition test, the value of test represented high activities compared with authentic sample - green tea and NDGA (nordihydroguaiaretic acid). In MMP-1 test, related to collagen protection and elasticity of skin, its inhibitory effect was measured over 75 %, and the phenolic compounds of AIF related with this activity were confirmed luteolin derivatives by using FT-IR spectroscopy, element analyzer (EA) and Liquid chromatography-MASS spectroscopy.

• Journal of Marine Life Science
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• v.5 no.1
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• pp.25-33
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• 2020

The Asan Bay, which has semi-diurnal tide with macro-tidal range, is affected by both freshwater discharge from the sluice gates in the sea dikes and tidal seawater inputs from the Yellow sea. Understanding water quality change in response to tides is important since tides can impact the short-term variations in physical and chemical water properties as well as the response of biological properties. The diel variations in water quality were seasonally investigated at 2 hour intervals from a fixed station in the Asan Bay. In the results, water temperature and salinity consistently fluctuated in phase or out of phase with tidal height. Especially salinity was positively correlated with tidal height. The concentrations of total suspended solids were higher in the bottom water than in the surface and fluctuated greatly over the tidal cycle recording higher values at low tide than at high tide. Nitrite+nitrate levels also fluctuated out of phase with tidal height and correlated negatively with tidal height. Other nutrients also showed a similar pattern. The pattern was distinct in July when freshwater was discharged before the field sampling. The concentrations of organic materials, total nitrogen and total phosphorus greatly fluctuated over the tidal cycle and were generally out of phase with tidal height. Most materials except particulate organic forms were correlated with salinity indicating that freshwater inputs were sources for the materials similarly to the dissolved inorganic nutrients. The results suggest that water quality (except dissolved oxygen and pH) and nutrients including organic materials was largely affected by tides in the Asan Bay.

• Journal of Life Science
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• v.31 no.7
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• pp.641-653
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• 2021

The purpose of this study was to confirm the antifungal activity, plant growth-promoting activity, and mineral solubilizing activity of 18 types of bacteria isolated purely from rhizosphere soil. The potential of isolates of the genus Bacillus and Pseudomonas as biocontrol agents was confirmed through the antifungal activity of these isolates. This activity has been determined to be due to various hydrolytic enzymes on the cell wall of plant pathogenic fungi and the production of siderophores in isolates. In addition, most of the isolates have been found to have aminocyclopropane-1-carboxylate deaminase production activity, indole-3-acetic acid production activity, and nitrogen fixation activity. These characteristics are believed to have a positive effect on root development, growth, and the productivity of crops via a reduction in the concentration of ethylene under conditions of environmental stress, to which plants are commonly exposed. In addition, on testing for the solubilizing activity of the isolates for phosphoric acid, silicon, calcium carbonate, and zinc, some isolates were found to have mineral solubilizing activities. Inoculation of these isolates during plant growth is expected to assist plant growth by converting nutrients necessary for growth into usable forms that can be absorbed by plants. The 18 isolated strains can be used as biocontrol agents due to their antifungal activity, plant growthpromoting activity, and mineral solubilizing activity.