• Korean Journal of Plant Resources
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• v.37 no.1
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• pp.22-34
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• 2024

Recently, in several regions of Korea, we discovered the occurrence of Sagina micropetala Rauschert and S. procumbens L. All the plants of the genus Sagina growing in Korea are 5-merous and belong to the sect. Spergella. However, the two taxa we discovered belong to the sect. Saginella and are 4-merous. In addition, morphological characteristics such as sepals during the fruiting season and seeds were significantly different from those of species of the genus Sagina that occur in Korea. To clearly identify these species, we compared and observed their primary morphological characteristics using illustrated books and literature. Morphologically, S. micropetala exhibits the following traits: pubescence along the leaf margin, horizontally spreading sepals with red margins, and convex protrusions on the seed surface. In contrast, S. procumbens can be distinguished by its pedicels, which are curved during the flowering season and erect during the fruiting season. This plant also has broadly ovate sepals with white or yellowish-green margins, and flat seed surface protrusions. In terms of molecular analyses, 19 samples of Sagina were divided into two clades (S. micropetala and S. procumbens), confirming the taxonomic identity of the Sagina spp.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.15 no.4
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• pp.158-165
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• 2010

Phytoplankton community structure is one of the indicators that can explain the enviromnental characteristics of coastal waters. In this study, phytoplankton community structure and water quality of aquaculture area were investigated for understanding regional enviromnental characteristics. Thirty stations in aquaculture areas of Tongyeong, southeast coast of Korea, were investigated monthly from January to December, 2009. Phytoplankton community, meteorologic dada and enviromnent factors including temperature, salinity, transparency, nutrients and chlorophyll a were also examined. Chaetoceros spp. and unidentified small flagellates were dominant species in all the year round. Pseudo-nitzschia spp., Dictyocha spp., and Nitzschia longissima were dominant in June to October being summer season, and Skeletonema costatum, Thalassiosira spp., Eucamphia zodiacus, Akashiwo sanguinea, Gymnodinium spp. and Asterionella japonicus appeared as dominant species in the rest of months. Dinoflagellate blooms occurred 3 times in near Hansan Bay and around Saryang-do, and the highest chlorophyll a was found in Hansan Bay. Species diversity of phytoplankton was lower in Hansan and Womnum Bay, and diatom was more abundant than dinoflagellates in Mireuk-do waters. These results showed that phytoplankton community varied by the seasonal and geographical characteristics, and recent increase of water temperature and heavy rain may affect on phytoplankton community structure.

• Journal of Korean Society of Forest Science
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• v.88 no.4
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• pp.510-522
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• 1999

The air pollutants ; $SO_2$, $SO{_4}^{-2}$, $NO{_3}^-$, $Cl^-$ are absorbed into soils through falling with dusts and rain from the atmosphere. The sources of heavy metal contaminants in the environments are agricultural and horticultural materials, sewage sludges, fossil fuel combustion, metallurgical industries, electronics and waste disposal etc.. The soils and hydrosphere can be polluted on the way of the circulation of these heavy metals. Studied pollutant anions are $SO{_4}^{-2}$, $NO{_3}^-$ and $Cl^-$ and heavy metals are Se, Mo, Zn, Cd, Pb, Mn, Cr, Co, V, As, Cu and Ni which are the elements to be concerned with the essentials for plants, with animal and human health. This study is with the aim of selecting the species of roadside trees and green space trees which have excellent absorption of air pollutants and heavy metals from the atmosphere and the soils in the urban area. Two areas are designated to carry out this study : urban area ; Kwangju city and rural area ; the yard of Forest Environment Institute of Chollanam-do, at Sanje-ri, Sampo-myum, Naju city, Chollanam-do (23km away from Kwangju). This study is carried out to understand the movement of anions and heavy metals from the soils to the trees in both areas, the absorption of anions and heavy metals from atmosphere into leaves and the amounts of anions and heavy metals in leaves and fine roots(< 1mm dia.) of roadside trees and green space trees in Kwangju and trees in the yard of Forest Environment Institute of Chollanam-do. The tree species selected for this study in both areas are Ginkgo biloba, Quercus acutissima, Cedrus deodara, Platanus occidentalis, Robinia pseudoacacia, Alnus japonica. Metasequoia glyptostroboides. Zekova serrata. Prunus serrulata var. spontanea, and Pinus densiflora. The results of the study are as follows : 1. $SO{_4}^{-2}$, $NO{_3}^-$ and $Cl^-$ concentrations are higher in the soils of the urban area than in those of the rural area, and $NO{_3}^-$ and $SO{_4}^{-2}$ are higher in the leaves than in the roots due to the absorption of the these pollutants through the stomata. 2. Ginkgo biloba, Robinia pseudoacacia. Zekova serrata, Quercus acutissima, and Platanus occidentalis can be adequated to the roadside trees and the environmental trees due to their good absorption of $NO{_3}^-$ and $SO{_4}^{-2}$. 3. Heavy metals in the soils of both areas are in the order of Mn > Zn > V > Cr > Pb > Ni > Cu > Mo> Cd, and in the leaves and roots of the trees in the both areas are in the order of Mn>Zn>Cr>Cu>V>Ni. Both orders are similar ones except V. There are more in the urban soils than in the rural soils in amount of Mn, Zn, Pb, V, Cu. 4. It is supposed that there is no antagonism between Mn and Zn in this study. 5. Se, Co and As are not detected in the soils, the leaves and the roots in both areas. Sn, Mo, Cd and Pb are also not detected in the leaves and roots in spite of considerable amount in the soils of both areas.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.7
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• pp.1109-1114
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• 2013

Microbial community analysis was performed on Tarak, a traditional Korean fermented milk product, by 16S rDNA cloning and pyrosequencing to obtain basic data for the standardization and systematization of the Tarak manufacturing process. Microbial analysis of the prokaryotic community revealed a slight difference in microbial abundance between Bontarak (n) and Tarak (n+1), but Firmicute was dominant at the phylum level. At the genus level, the Lactobacillus and Leuconostoc genera constituted over 90% of the population in Bontarak, but Lactococcus was the dominant genus in Tarak. Bontarak and Tarak showed further differences at the species level. Leuconostoc citreum was the dominant species in Bontarak, constituting 40% of the population. In eukaryotic community analysis, all samples were composed of Ascomycota at the phylum level. At the genus level, Saccharomyces was dominant in Bontarak (85% of the population), while Issatchenkia was dominant in Tarak (95% of the population). At the species level, Saccharomyces cerevisiae was detected at a relative abundance in Bontarak (82%), and Pichia kudriavzevii was the dominant species in Tarak, with a relative abundance of 95%. Sensory evaluation indicated that Tarak had a better appearance and texture than Bontarak. As sweetness was not significantly different between the two samples just slightly higher in Tarak, this was likely due to a significant decrease in sourness in Tarak. These results suggest that the microbial community used affects the quality of Tarak produced. Thus, a stable microbial community must be maintained for the production of Tarak with consistent quality.

• Journal of Life Science
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• v.33 no.7
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• pp.565-573
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• 2023

In light of the complex interactions between the host animal and its resident gut microbiomes, studies of these microbial communities as a means to improve cattle production are important. This study was conducted to analyze the intestinal microorganisms of Holstein (HT) and Jersey (JS), raised in Korea and to clarify the differences in microbial structures according to cattle species through next-generation sequencing. The alpha-diversity analysis revealed that most species richness and diversity indices were significantly higher in JS than in HT whereas phylogenetic diversity, which is the sum of taxonomic distances, is not significant. Microbial composition analysis showed that the intestinal microbial community structure of the two groups differed. In the both groups, a significant correlation was observed among the distribution of several microbes at the family level. In particular, a highly significant correlation (p<0.0001) among a variety of microbial distributions was found in JS. Beta-diversity analyis was to performed to statistically verify whether a difference exists in the intestinal microbial community structure of the two groups. Principal coordinate analysis and unweighted pair group method with arithmetic mean (UPGMA) clustering analysis showed separation between the HT and JS clusters. Meanwhile, permutational multivariate analysis of variance (PERMANOVA) revealed that their microbial structures are significantly different (p<0.0001). LEfSe biomarker analysis was performed to discover the differenc microbial features between the two groups. We found that several microbes, such as Firmicutes, Bacilli, Moraxellaceae and Pseudomonadales account for most of the difference in intestinal microbial community structure between the two groups.

• Journal of Life Science
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• v.31 no.12
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• pp.1079-1087
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• 2021

To analyze gut microbiota of livestock in Korea and compare taxonomic differences, we conducted 16S rRNA metagenomic analysis through next-generation sequencing. Fecal samples from broiler chickens, pigs, and cattle were collected from domestic feedlots randomly. α-diversity results showed that significant differences in estimated species richness estimates (Chao1 and ACE, Abundance-based coverage estimators) and species richness index (OUTs, Operational taxonomic units) were identified among the three groups. However, NPShannon, Shannon, and Simpson indices revealed that abundance and evenness of the species were statistically significant only for poultry (broiler chickens) and mammals (pigs and cattle). Firmicutes was the most predominant phylum in the three groups of fecal samples. Linear discriminant (LDA) effect size (LEfSe) analysis was conducted to reveal the ranking order of abundant taxa in each of the fecal samples. A size-effect over 2.0 on the logarithmic LDA score was used as a discriminative functional biomarker. As shown by the fecal analysis at the genus level, broiler chickens were characterized by the presence of Weissella and Lactobacillus, as well as pigs were characterized by the presence of provetella and cattele were characterized by the presence of Acinetobacter. A permutational multivariate analysis of variance (PERMANOVA) showed that differences of microbial clusters among three groups were significant at the confidence level. (p=0.001). This study provides basic data that could be useful in future research on microorganisms associated with performance growth, as well as in studies on the livestock gut microbiome to increase productivity in the domestic livestock industry.

• Journal of Aquaculture
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• v.21 no.3
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• pp.157-166
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• 2008

Species composition and standing crop of phytoplankton were investigated in the ark shell Scapharca broughtonii farming areas from March, 2006 to February, 2007 in Jinhae Bay. Water temperature ranged from 7.56 to $25.90^{\circ}C$, salinity from 13.74 to 34.78 psu, dissolved oxygen from 4.13 to 13.20 mg/L, chlorophyll $\alpha$ from 2.77 to 104.98 $mg/m^2$ and pH from 7.83 to 8.65. Dominant species was Nitzschia and Rhizosolenia from March to May, Skeletonama costatum and Prorocentrum from June to August, Skeletonama costatum, Thalassiosira, Chaetoceros from September to November and Thalassiosira, Chaetoceros from December to February. Colonial diatoms were more dominant than the single cell diatoms. Standing crop was the highest in July at three stations. Standing crop of Skeletonama costatum was the highest as 1,760.0 cells/mL at St. 1, 1,075.2 cells/mL at St. 2 and 698.4 cells/mL at St. 3 in July.

• Korean Journal of Ecology and Environment
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• v.54 no.1
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• pp.24-38
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• 2021

Microhabitat In the upper stream is created by various environment variables such as the bottom substrate and the physicochemical factors, and may influence the distribution of benthic macroinvertebrates. We investigated the bottom substrate and environmental variables influencing the distribution of benthic macroinvertebrate in 26 stream-type waterways established at upper reaches of Geum River. During study period, total 85 families, 160 species, 9305 individuals of benthic macroinvertebrates were recorded. The stream-type waterways, where the bottom substrates consist mainly of pebble (16~64 mm) and cobble (64~256 mm) or with rapid water velocity (more than 0.2 m/s) and high dissolved oxygen (more than 120%), were supported by high species diversity of benthic macroinvertebrate. Hierological cluster analysis and the nonparametric multidimensional scale (NMDS) divided 26 stream-type waterways into a total of three clusters. In Cluster 1, the invertebrate species, such as Branchiura sowerbyi, Cloeon dipterum, Ischnura asiatica, Paracercion calamorum, and Radix auricularia, closely related to aquatic macrophytes, and Chironomidae spp., Limnodrilus gotoi, and Tanypodinae sp. were abundant in waterways, with high coverage of silt and clay as well as high turbidity and total nitrogen. The benthic macroinvertebrate species (Cheumatopsyche brevilineata, Drunella ishiyamana, Dugesia japonica, Ephemera orientalis, Gumaga KUa, Macrostemum radiatum, Potamanthus formosus, Semisulcospira libertine, Stenelmis vulgaris, and Teloganopsis punctisetae) included in Cluster 2 were dominated in sites with high cover rates of pebble and gravel. Cluster 3 was predominantly covered by the Cobbles, was supported by Simulium sp. Such a clear distinction in the study sites means that each stream-type waterways is governed by a clear habitat environment. In the case of some sites with low species diversity, improvement measures are required to restore nature, such as improving the function of inflows and outflows, creating meandering channel, and inducing the settlement of littoral vegetation.

• Journal of Wetlands Research
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• v.25 no.3
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• pp.205-212
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• 2023

This study was attempted to find out how the ecological niche and interspecies relationship of Quercus aliena and Q. serrata, which are the main constituents of potential natural vegetation along the riverside of mountains in Korea, under climate change conditions. To this end, soil moisture and soil nutrients were treated with 4 grad ients under climate change conditions with elevated CO₂ and temperature, plants we re harvested at the end of the growing season, growth responses of traits were measured, ecological niche breadth and overlap were calculated, and it was compared with that of the control group(ambient condition). In addition, the relationship between the two species was analyzed by principal component analysis using trait values. As a result, the ecological niche breadth of Q. aliena was wider than that of Q. serrata under the moisture environment conditions under climate change. Under nutrient conditions, the ecological niche of the two species were similar. In addition, the ecological overlap for soil moisture of Q. aliena and Q. serrata was wider than the soil nutrient gradient under climate change. The species with traits in which the increase in ecological niche breadth due to climate change occurred more than the decrease was Q. aliena in both water and nutrient gradients. And in the responses of the population level, due to climate change, the adaptability of Q. aliena was higher than that of Q. serrata under the soil moisture condition, but the two species were similar under the nutrient condition. These results mean that the competition between the two species occurs more severely in the water environment under climate change conditions, and at that time, Q. aliena has higher adaptability than Q. serrata.

• Analytical Science and Technology
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• v.24 no.5
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• pp.387-394
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• 2011

This study was performed to investigate the contents and leaching characteristics of hazardous wastes from the paint industry. In order to establish a hazardous waste list, samples from industrial discharge have been analyzed for 8 non-regulated inorganic hazardous substances (i.e., Sb, Ni, F, V, Ba, Zn, Be, Se). In more detail, hazardous waste samples from a total of 64 workplaces, e.g. manufacture, formulation, supply and use (MFSU) of coatings, adhesives, sealants and printing inks processing, have been chosen and analyzed. Contents and leaching tests for inorganic metal species in samples show that the non-regulated hazardous substances satisfy all the criteria, while quantitative analyses reveal that some samples of the discharged wastes exceeded the criteria proposed by NIER (National Instituted of Environmental Research). In conclusion, we expect the outcome of this study to align the classification system of hazardous waste management in South Korea with international legislations, and consequently contribute to reduce environmental pollution as well as health risks by toxic wastes.