• Journal of Environmental Science International
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• v.33 no.4
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• pp.257-268
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• 2024

This study investigated the growth characteristics of Euonymus japonicus, Hedera helix, and Peperomia puteolata treated with different calcium chloride (CaCl₂) concentrations to evaluate salt tolerance limits in hydroculture cultivation. Six concentrations of CaCl₂ (0, 1, 2, 5, 10, and 15 g·L^-1 referred to as Cont., C1, C2, C5, C10, and C15) were applied to solution - grown plant species. The survival rate, growth index, plant height, plant width, leaf width, leaf length, number of leaves, and relative chlorophyll contents were measured at monthly intervals. Euonymus japonicus, Hedera helix, and Peperomia puteolata survived up to C2, C5, and C10 at each CaCl₂ concentration. The Euonymus japonicus was higher in the C1 treatment than in the Cont. for most growth characteristics. Hedera helix had the highest leaf width, leaf length, and number of leaves in the Cont., a significant difference was observed compared with the C1 treatment. The chlorophyll content did not differ significantly between the C5 and Cont. treatments. The leaf width and length of Peperomia puteolata were greater in the C2 and C1 treatments than in the Cont., whereas the number of leaves and chlorophyll content were the highest in C5. Dry weight analysis revealed that Euonymus japonicus, Hedera helix, and Peperomia puteolata were the lowest in the Cont. treatments. Euonymus japonicus was 74% in C15, and Hedera helix, and Peperomia puteolata were analyzed at approximately 37%- 50% and 9%-14%, respectively, regardless of the concentration in the CaCl₂ treatment groups. In indoor hydroponic cultivation, the salt tolerance limit concentrations of Euonymus japonicus, Hedera helix, and Peperomia puteolata are 2, 5, and 10 g·L^-1, respectively, indicating that hydroculture management techniques should be applied at higher concentrations.

• Journal of fish pathology
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• v.37 no.1
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• pp.61-69
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• 2024

In this study, bacterial disease monitoring was conducted from July to November 2022 for three representative bacterial species (Streptococcus parauberis, Vibrio spp. and Edwardsiella piscicida) to investigate the occurrence of bacterial diseases in farmed olive flounder (Paralichthys olivaceus) on Jeju. Over a period of five months, 3,146 olive flounders were tested. The average length and weight of the olive flounder that were sampled for the disease were found to be 32.1 cm and 357.9 g, respectively. Bacteria were detected in 1,228 olive flounders, of which 24.6% were identified as Vibrio spp.. S. parauberis and E. piscicida were identified in 6.3% and 3.2% respectively, and 3% were unknown strains that could not be identified. Also, 41 (1.3%) olive flounders were found to have both S. parauberis and Vibrio spp. and 23 (0.7%) olive flounders were found to have both E. piscicida and Vibrio spp.. In particular, S. parauberis, Vibrio spp. (V. scophthalmi) and E. piscicida were detected simultaneously in one olive flounder. In fish infected with E. piscicida, the most obvious external signs were hernias and ascites.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.1
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• pp.56-62
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• 2009

Stable carbon isotope analysis was used to investigate the autotrophic carbon sources supporting fisheries in three coastal bay systems of the southern coast of Korea. Carbon isotope ratios (${\delta}^{13}C$) of 31 fish species were analysed and compared with those of a range of potential primary food sources [e.g., seagrass (Zostera marina), seagrass epiphytes, benthic microalgae, macroalgae, marine particulate organic matter (marine POM), marsh plant (Phragmites australis) and terrestrial POM]. ${\delta}^{13}C$ values (range, -16.2${\sim}$-8.3‰) of fishes from the coastal embayment systems were overlapped with those of seagrass (-8.3${\pm}$1.9‰), seagrass epiphytes (-12.4${\pm}$0.6‰), benthic microalgae (-15.4${\pm}$1.6‰) and macroalgae (-16.0${\pm}$1.8‰). In addition, fishes (-12.9${\pm}$1.5‰) from the study area had distinctly higher ${\delta}^{13}C$ values compared to those collected in offshore sites (-17.3${\pm}$0.8‰) of the southern sea of Korea and Nakdong River (-23.2${\pm}$1.6‰). This result indicates that carbon supporting fish communities of these coastal bay systems is mainly derived from the local benthic producers.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.13 no.4
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• pp.325-332
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• 2008

To characterize the initiation, propagation and termination of Cochlodinium polykrikoides blooms in the southeast coastal waters of Korea, 2007, we have analyzed the data set of phytoplankton composition, physical and chemical water properties, and meterological data. The development of C. polykrikoides bloom in 2007 can be summarized in three steps. The first stage from middle of July to end of August was characterized by an unusually persistent and strong southerly wind. C. polykrikoides blooms established already by the strong wind in the middle of south coastal waters were advected intermittently into the study area. Accordingly, highly variable cell densities of C. polykrikoides were observed. At the second stage a favorable growing conditions for C. polykrikoides was developed, which was directed by changes in wind direction from south to northeast and thus enhanced transportation of offshore waters into inshore (August 8 to 30). C. polykrikoides bloom occurred through typical mechanism and showed high cell density. The last stage was represented by disappearance of C. polykrikoides. Typoon 'Nari' carrying heavy rain brought an unfavorable habitat to C. polykrikoides. Low saline condition formed in coastal water due to typoon effects continuously drove the dominant species to diatoms and flagellates which were prevailing over C. polykrikoides in this circumstances(from the middle of September). These stepwise processes could be the causative mechanism of the extraordinarily persistent C. polykrikoides bloom observed in southeast coastal water of Korea, 2007.

• Journal of Life Science
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• v.22 no.4
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• pp.524-531
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• 2012

Soybean is one of the most common food materials causing food hypersensitivity reactions in Korea. In this study, we have investigated the effect of roasting and fermentation on the allergenicity of soybean. Three kinds of soybean ($Daepung$, $Daewon$, and $Taegwang$) were prepared as raw, roasted, and fermented by $Bacillus$ $subtilis$ GSK 3580, and then their proteins were extracted. The proteins were separated using SDS-PAGE, and the detection of IgE specific to soybean proteins was performed by immunoblotting using 7 sera of soybean allergy patients and non-allergic control individuals. Serum specific IgE to soybean was measured by ELISA. The SDS-PAGE of raw soybean proteins showed various-sized bands ranging from 9 to 76 kDa, which are known as major allergens. In particular, 9, 21, 34, 52, 72, and 76 kDa proteins are known as LTP, Kunits trypsin inhibitor, $Gly$ m Bd 30K, ${\beta}$-subunit, ${\alpha}$-subunit, and ${\alpha}$'-subunit of ${\beta}$-conglycinin, respectively; these are major allergens in soybean. In contrast, only peptides of less than 35 kDa were found in roasted and fermented soybeans. IgE immunoblot analysis of three roasted species of soybeans commonly detected at 38-40 kDa and 10-15 kDa. The protein bands in fermented soybean showed very weak signals or were not detected. In addition, the reactivity of most patients' sera to soybean was decreased after roasting and fermentation. With these results, it may be concluded that the allergenicity of soybeans is reduced by the roasting and fermentation processes. It is supposed that allergenic proteins in soybean were degraded by heat treatment methods and proteolytic enzymes were secreted from fermenting microorganisms.

• Journal of Korean Society of Forest Science
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• v.31 no.1
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• pp.1-7
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• 1976

When haploid plant would be appeared by the anther culture, the large quantity of young plant multiplied maternal inheritance and the same pure line rapidly in the short length of time, which will be effected to cut down much expences efforts and time for the production of seeds or seedlings. Therefore, the development of the technique for this would be much profited in the country industry. In the late of a few years studies were early attempted in this field, but up this time there were a few success of plants only and none of perennial plant. In this status of the country condition required earnestly for the development of the green industry, this researcher attempted to culture the anther of late uninucleate microspore or early binucleate microspore of the Prunus mume and other three psecies, economic trees estimated specially economic, on the place of Modified Murashige and Skoog's medium supliment with Kinetine, 2.4-D, and N.A.A for inducing haploid plants. The obtained results were as follows: 1. 2,000 anthers were cultured and there were shown that 2N callus in Prunus mume had 82 as 4.1%, 2N callus in Prunus tomentosa 15 as 0.8%, 2 N callus in Prunus salisina 75 as 4% 2. N callus had shown 40 as 2% from Prunus armeniaca var. ansu only, and the other trees showed all 2N callus. 3. Callus had appeared in every tree but 2N callus appeared was all filaments and there showed from only connective tissue N callus appeared was all from anther locule inside. 4. Then Prunus armeniaca var. ansu only was not callus of somatic anther tissue origin, but as there was callus origined from microspore which was changed in to swollen microspores or polynucleate microspores, it was certained to need haploid plant.

• Korean Journal of Ichthyology
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• v.19 no.4
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• pp.371-377
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• 2007

The passive integrated transponder (PIT) telemetry is a useful method for investigating fish population dynamics, community structure and migration. It can be applied for small fishes (TL<100 mm) because of its tiny size and light weight. The survival rate of PIT tag was investigated on 4 small size cyprindae fish species, Carassius gibelio langsdorfi (n=34, standard length; $91.9{\pm}0.9mm$, body weight; $21.2{\pm}0.9g$), Hypophthalmichthys molitrix (n=16, SL; $75.1{\pm}0.9mm$, BW; $6.0{\pm}0.2g$), Pseudorasbora parva (n=30, SL; $51.4{\pm}1.1mm$, BW; $2.7{\pm}0.2g$) and Phoxinus phoxinus (n=37, SL; $70.6{\pm}1.4mm$, BW; $8.2{\pm}0.5g$) under age 1 for applicability and effectiveness. We used three type tags including a small (length 11.0 mm, diameter 2.1 mm, weight 0.088 g), middle (20 mm, 3.5 mm, 0.102 g), large (30 mm, 3.5 mm, 0.298 g) size. After 30 days of tag insertion, survival rate of 117 individuals were 58.1% (large tag, 50.0%; middle tag, 57.5%; small tag, 61.4%). Survival rates varied between three types of tags because the abdominal cavity of each individual was different size. The death was due to surgical damage. If we apply tagging systems on field research of the Korean freshwater fish, the PIT tag will be effective method for analyzing fish ecology.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.3
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• pp.381-387
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• 2015

This study was firstly conducted to investigate changes of vegetation and soil characteristics in reclaimed land applied with solidified sewage sludge for the cultivation of bioenergy crops. Each vegetation survey site was approximately $15m{\times}3m$ on the inside of each experimental plot that consisted of 50% (A-1), 30% (A-2), 15% (A-3), and 5% (A-4) mixture of solidified sewage sludge, and original reclaimed soil (ORS). After the application of solidified sewage sludge, we monitored the changes of vegetation and soil properties for three years. In first year, soil pH, electrical conductivity (EC) and exchangeable $Ca^{2+}$ content was 9.4~10.8, $9.10{\sim}14.41\;dS\;m^{-1}$, and $62.1{\sim}204.2\;cmol\;kg^{-1}$, respectively, while three years later, it decreased to 8.1~8.4, $1.65{\sim}5.98\;dS\;m^{-1}$, and $21.9{\sim}43.1\;cmol\;kg^{-1}$, respectively. These results indicated that several of soil chemical elements which have nagative impacts on the plant growth in the plots of mixtures of solidified sewage sludge, steadily declined as the years go by. The vegetations in each survey site were recorded as 6 families and 12 species in 2014, while the vegetations were not occurred at all survey sites in 2012, and only halophytes as Phragmites australis and Suaeda asparagoides were observed in 2013. Diversity of vegetation, which was calculated by shannon index (H'), increased as the season progressed at each experimental plot applied with solidified sewage sludge. In original reclaimed soil, however, there was showed the high community similarity of vegetation due to the fact that P. australis and S. asparagoides were only occurred for survey periods.

• Journal of Animal Environmental Science
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• v.13 no.2
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• pp.129-138
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• 2007

A natural deodorizing agent (NDA) was made using pine cone byproduct, and its effects on malodor emission and composting were analyzed in this study. NDA was manufactured by mixing pine cone byproduct with three species of microorganisms and water containing mineral nutrients and molasses, and then by incubating for 48 hours at $30^{\circ}C$. Lab scale experiments were done with three treatment groups, T1 (control, sawdust treatment), T2 (microorganisms and sawdust treatment group), and T3 (NDA and sawdust treatment group). During composting, temperatures reached over $55^{\circ}C$, a minimum temperature for the inactivation of pathogenic microorganisms. No differences were found in physicochemical composition of compost among treatments. However, it was observed that over usage of NDA could obstruct temperature increase, since the biodegradation rate of organic matter of NDA was relatively low, Nitrogen loss due to ammonia gas emission, which normally happens during composting, was reduced by using NDA, and hence the nitrogen level of final compost was higher in T3 than in others. During experiment, it was found that ammonia gas emission was entirely lasted through compositing duration, but the $CH_3SH$ and $H_2S$ gases were produced only at early stage of composting. The ammonia concentration trapped in $H_2SO_4$ solution during 31 days of composting in T1, T2 and T3 was 12,660mg/L, 11,598mg/L and 7,367mg/L, respectively, showing distinguishable reduction of ammonia gas emission in T3. The emissions of $CH_3SH$ and $H_2S$ gases were also remarkably reduced in T3. Based on these obtained results, usage of the deodorizing agent made with pine cone byproduct could reduce the emission of malodor during composting, without any deterioration of compost quality.

• Korean Journal of Ecology and Environment
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• v.44 no.3
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• pp.253-263
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• 2011

This study was conducted to gain preliminary data for restoration and management of constructed small-scale ponds in paddy fields through analysis of their physicochemical and biological properties. A field survey was performed at 13 small-scale ponds located in paddy fields from August 2009 to October 2010. Structural properties, water quality, soil characteristics and fish fauna were measured. Results showed that small-scale ponds without frames might lose their function over time because of crumbling walls. Therefore, it is necessary for these ponds to have frames for soil protection and sustainable maintenance. Chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) concentration were higher than the water quality standard for agricultural water in small-scale ponds. In particular, TN concentration was 8.03 mg $L^{-1}$ and over 8 times the water quality standard because of the presence of livestock such as cows and pigs in the study areas. Sand, organic matter and available phosphorus contents of soil in small-scale ponds was 53.4${\pm}$16.6%, 21.8${\pm}$9.74 g $kg^{-1}$ and 12.8${\pm}$7.59 mg $kg^{-1}$, respectively indicating that sand and available phosphorus contents were suitable for plants in small-scale ponds, but organic matter contents was somewhat low in newly constructed small-scale ponds, and would take some time to stabilize for plant growing. Fish fauna was not diverse with only 4 species at all sites surveyed. Collected fishes share a common feature that they all inhabit paddy fields or canals with shallow water depth. In this study, all ponds were not linked to the streams and canals around them. It appears that connection to adjacent streams was the major factor controlling fish fauna in small-scale ponds. The results of statistical analysis were classified into three groups. Factor 1 was 26.3%, which shows a structural properties such as area and depth of small-scale pond. As for factor 2, it appears on 20.1%, showing water quality like a TP, suspended solids (SS) and COD. Small-scale ponds were classified into three groups by factor scores. Group I consisted of 6 small-scale ponds, which were larger than the others. Group III had higher water quality than the others. We conclude that the most important points to be considered for restoration and management of small-scale ponds is connection with adjacent streams or ditches and depth and size of the small-scale pond.