• Korean Journal of Microbiology
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• v.46 no.4
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• pp.366-374
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• 2010

Culture-dependent RFLP and culture-independent DGGE were employed to investigate the bacterial community associated with the marine sponge Spirastrella abata. A total of 164 bacterial strains associated with the sponge were cultivated using Zobell and Natural sea salt media. PCR amplicons of the 16S rDNA from the bacterial strains were digested with the restriction enzymes HaeIII and MspI, and then assigned into different groups according to their restriction patterns. The 16S rDNA sequences derived from RFLP patterns showed more than 95% similarities compared with known bacterial species, and the isolates belonged to four phyla, Proteobacteria (Alphaproteobacteria, Gammaproteobacteria), Actinobacteria, Firmicutes, and Bacteriodetes, of which Alphaproteobacteria was dominant. DGGE fingerprinting of 16S rDNAs amplified from the sponge- derived total gDNA showed five major DGGE bands, and their sequences showed more than 96% similarities compared with available sequences. The sequences derived from DGGE bands revealed high similarity with the uncultured bacterial clones. DGGE revealed that bacterial community consisted of four phyla, including Proteobacteria (Alphaproteobacteria, Gammaproteobacteria), Actinobacteria, Spirochetes, and Chloroflexi. Alphaproteobacteria, Gammaproteobacteria, and Actinobacteria were commonly found in bacteria associated with S. abata by both RFLP and DGGE methods; however, overall bacterial community in the sponge differed depending on the analysis methods.

• Journal of the Korean Institute of Landscape Architecture
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• v.27 no.4
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• pp.1-12
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• 1999

This study aims to find basic data for using the quantitative assessment of the sustainability and establishing the systematic index of the planning for local cities to consider the environmentally sound and sustainable development. The research designs to review professional responding to surveys preceded by separate questionnaires and interviews from book reviews, and suggests to make an assessment model of the sustainability for local cities. The research found consequently as follows. Firstly, the research survey items were decides totally 52, grouped 9 assessmental issues and distributed under 4 assessmental domains for the sustainability from the references of book reviews. Secondly, the research result concentrated on the followings from the professional responding to surveys. 1. A most influent factor is the distribution of animals and plants in a nature domain. The next influent factors are the ratio of mass-transportation systems, the numbers of the species of animals and plants, the acreage of conservative forestry, the numbers of reused water resources, and the usage number of water supply, orderly in the nature domain. 2. A most influent factor is the usage number of synthetic detergents in a pollution domain. The next influent factors are the volume of waste water, the number of registered vehicles, the degree of soil pollution, and the charge of development imposition, orderly in the pollution domain. 3. A most influent factor is the acreage of athletic facilities, in an urban domain. the next influent factors are the acreage of recreational facilities, the number and acreage of cultural assets, the number of cultural facilities, the acreage of landscape conservation area, the charge of cultural asset management, orderly in the urban domain. 4. A most influent factor is the number of waste disposal facilities in a participation domain. The next influent factors are the capacity of reused waste, the usage of synthetic detergents, the ratio of waste water disposal, orderly in the participation domain. 5. A most contributed influent domain to the assessment of the sustainability for local cities is the urban domain. The next influent domains are nature domain, participation domain, and pollution domain, orderly in the contribution of the assessment of the sustainability. But, the pollution domain is little relationship with the sustainability. Therefore, it is clear that the abundant greens and the improved level of culture are dominant influences on the sustainabiligy, as like improving the ratio of roadside trees, the acreage of parks, and enlarging the number of cultural facilities.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.3
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• pp.627-631
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• 2007

The factors affecting on sludge sedimentation are reported as F/M ratio, ingredient, composition of influent substrate, dissolved oxygen concentration, temperature, pH, filamentous bacteria and SRT. Aeration tank applying Bacillus sp. has an important role for maintaining the dominant microorganism species to make steady progress for spore growth affecting sedimentation. This research aims to investigate the affecting factor for the sedimentation in B3 system and RABC system with aeration tank applying tapered aeration. Extracellular polymeric substances(EPS), protein and carbohydrate can be produced for the extreme condition, that is down to 0.2 mg/L of dissolved oxygen in the aeration tank. This research found out the relation between the sedimentation and the EPS production, especially the ratio of protein/carbohydrate. The spore of Bacillus sp. was formed at the low DO then microorganisms produced EPS. The results showed that the production of EPS was 109.95 mgEPS/gSS at 1.6 mg/L of DO, however it was 131.77 mgEPS/gSS at 0.5 mg/L of DO. The sedimentation was affected by protein content in EPS and the ratio of protein and carbohydrate. The settleability of sludge was not affected by the ratio of protein/carbohydrate in B3 process, meanwhile settleability was affected by the ratio of it in RABC process, respectively.

• The Korean Journal of Malacology
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• v.19 no.2
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• pp.143-152
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• 2003

Water temperature during the culturing period was 10.4-25.5$^{\circ}C$ and there was a little difference between rearing sites. Salinity (25.00-31.17 psu) and DO (over 6.13 mg/l) showed reasonable condition for the growth of bay scallop. Concentrations of chlorophyll-a were ranged 1.69-7.40 $^{\mu}$g/l, and they fluctuated monthly in the every sampling site. During the growing period from June to October, dominant phytoplankton species were Ceratium sp. in Nammeon and Hoejin, Chaetoceros sp. in Dolsan. Density of phytoplankton was high in July, August and October, but it was low in September and November. When young bay scallops were cultured for 185 days in Nammyeon, Hoejin and Dolsan, shell heights were grown for 0.19 mm/day, 0.18 mm/day and 0.16 mm/day, respectively, and total weights were increased 0.16 g/day, 0.16 g/day and 0.13 g/day, respectively. Daily growth rates of shell height were 0.606%, 0.581% and 0.549%, and daily growth rates of total weight were 1.972%, 1.857% and 1.746%, respectively. Maximum predicted values of shell height calculated by von Bertalanffy growth model were 52.62 mm, 51.74 mm and 48.91 mm, respectively. Survival rate was the highest in Nammyeon (87.0%), but the rates in Hoejin and Dolsan sharply decreased after November.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.12
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• pp.861-866
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• 2013

The aim of this study was to investigate the biodegradation of dissolved organic matter derived from animal carcass disposal soil using soil inhabited bacteria and to identify the bacteria involved in the biodegradation. The two soils were obtained from the animal carcass burial sites located in Anseong, Gyeonggi-do, Korea. The results indicated that during the biodegradation experiments (56 days), 48% of dissolved organic carbon (DOC) was mineralized within 13 days in soil-derived solution 1 (initial DOC = 19.88 mgC/L), and the DOC concentration at 56 days was $8.8{\pm}0.4$ mg C/L, indicating 56% mineralization of DOC. In soil-derived solution 2 (initial DOC = 19.80 mgC/L), DOC was mineralized drastically within 13 days, and the DOC concentration was decreased to $6.0{\pm}0.4$ mg C/L at 56 days (76% mineralization of DOC). Unlike DOC value, the specific UV absorbance ($SUVA_{254}$) value, an indicator of proportion of aromatic structures in total organic carbon, tended to increase until 21 days and then decreased thereafter. The $SUVA_{254}$ values in soil-derived solutions 1 and 2 were the highest at 21 days. The microbial analysis demonstrated that Pseudomonas fluorescens, Achromobacter xylosoxidans, Nocardioides simplex, Pseudomonas mandelii, Bosea sp. were detected at 14 days of incubation, whereas Pseudomonas veronii appeared as a dominant species at 56 days.

• Korean Journal of Environmental Biology
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• v.25 no.4
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• pp.336-341
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• 2007

To investigate the variations of physico-chemical factors and microbial population, in ten stations at water region of coastal area of Chagwi-Do, Nutritive salts, water temperature, transparency, suspended solid, salinity, COD, DO, pH, heterotrophic bacteria, were analysed three times in September, November in 2004 and February in 2005. Heterotrophic bacteria in surface water was $3.5\times10^1\sim1.16\times10^3\;cfu\;mL^{-1}$, $0.4\times10^1\sim5.6\times10^1\;cfu\;mL^{-1}$, $0.4\times10^1\sim7.8\times10^1$ and bottom water counted $4.5\times10^1\sim1.0\times10^3\;cfu\;mL^{-1}$, $1.2\times10^1\sim1.5\times10^2\;cfu\;mL^{-1}$, $0.4\times10^1\sim4.4\times10^1\;cfu\;mL^{-1}$ in September, November 2004 and February 2005, respectively. The dominant species isolated from the coastal area of Chagwi-Do were identified to be Vibrio spp., Pseudoalteromonas spp. Psuedomonas spp, Bacillus spp., Alteromonas spp., Aeromonas spp., Psychrobacter spp., and Flavobacterium spp.

• Ecology and Resilient Infrastructure
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• v.3 no.4
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• pp.322-326
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• 2016

The distribution of floodplain vegetation is mainly affected by hydrological and hydraulic processes. In this study, we investigated changes in the vegetation distribution due to flood discharge alteration, and the relationship between the vegetation types and the flood frequency during the last ten-year period in the Cheongmi-cheon Stream. Flood discharge of the Cheongmi-cheon Stream tended to decrease from 2006 to 2016. It has greatly decreased to less than $160m^3/s$ since 2013. This resulted in the settlement of Phragmites japonica to the wide sand bar at the Cheongmi-cheon Stream, even though it had sparse vegetation before 2013. The sand bar was fully covered with P. japonica in 2016. Vegetation communities in the floodplain were classified by dominant species, i.e. the annual-hygrophytic, the perennial hygrophytic and the mesophytic communities. Analysis of the relationship between the vegetation communities and the flood frequency shows the annual hygrophytes, perennial hygrophytes and the mesophytes communities distributed in the range of under 1 year, 1-10 year and over 7 year flood inundation area, respectively. In conclusion, distribution of the floodplain vegetation is closely related with the flood discharge and frequency in the Cheongmi-cheon Stream.

• Korean Journal of Remote Sensing
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• v.27 no.4
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• pp.457-466
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• 2011

The objectives of this study are to produce level 3 type LULC map and analysis of phenological features of North Korea, ISODATA clustering of the 88scenes of MVC of MODIS NDVI in 2008 and 8scenes in 2009 was carried out. Analysis of phenological phases based mapping method was conducted, In level 2 type map, the confusion matrix was summarized and Kappa coefficient was calculated. Total of 27 typical habitat types that represent the dominant species or vegetation density that cover land surface of North Korea in 2008 were made. The total of 27 classes includes the 17 forest biotopes, 7 different croplands, 2 built up types and one water body. Dormancy phase of winter (${\sigma}^2$ = 0.348) and green up phase in spring (${\sigma}^2$ = 0.347) displays phenological dynamics when much vegetation growth changes take place. Overall accuracy is (851/955) 85.85% and Kappa coefficient is 0.84. Phenological phase based mapping method was possible to minimize classification error when analyzing the inaccessible land of North Korea.

• Korean Journal of Ecology and Environment
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• v.48 no.4
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• pp.263-271
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• 2015

To evaluate the relationship between dynamics of cyanobacteria and odorous compounds, a monthly monitoring of water quality and phytoplankton were conducted at the three serial lakes (Lake Ui-am, Lake Cheong-pyeong and Lake Pal-dang) in the North Han River for 11 times from May 2014 to March 2015. In the three serial lakes, phytoplankton communities showed that seasonal changes in Bacillariophyceae-Cyanophyceae-Bacillariophyceae. Anabaena and Pseudanabaena were dominant species in August and September 2014. At the same time the odors (Geosmin, 2-MIB) were also detected with high concentration. Relationship between environmental factors and cyanobacterial abundance showed a significant correlation with Anabaena circinalis and geosmin (r=0.983, p<0.01). In the case of Pseudanabaena limnetica showed a significant correlation of total nitrogen (r=0.685, p<0.01) and NO3-N (r=0.723, p<0.01). In addition, similarly Pseudanabaena limnetica and 2-MIB (r=0.717, p<0.01) was high. The odorous compounds appeared in the North Han River water were considered to be a direct relationship with cyanobacteria.

• Ocean Science Journal
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• v.40 no.3
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• pp.167-176
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• 2005

A time-series sediment trap was deployed at 1,034 m water depth in the eastern Bransfield Strait for a complete year from December 25, 1998 to December 24, 1999. About 99% of total mass flux was trapped during an austral summer, showing distinct seasonal variation. Biogenic particles (biogenic opal, particulate organic carbon, and calcium carbonate) account for about two thirds of annual total mass flux $(49.2\;g\;m^{-2})$, among which biogenic opal flux is the most dominant (42% of the total flux). A positive relationship (except January) between biogenic opal and total organic carbon fluxes suggests that these two variables were coupled, due to the surface-water production (mainly diatoms). The relatively low $\delta^{13}C$ values of settling particles result from effects on C-fixation processes at low temperature and the high $CO_2$ availability to phytoplankton. The correspondingly low $\delta^{l5}N$ values are due to intense and steady input of nitrates into surface waters, reflecting an unlikely nitrate isotope fractionation by degree of surface-water production. The $\delta^{l5}N$ and $\delta^{l3}C$ values of sinking particles increased from the beginning to the end of a presumed phytoplankton bloom, except for anomalous $\delta^{l5}N$ values. Krill and the zooplankton fecal pellets, the most important carriers of sinking particles, may have contributed gradually to the increasing $\delta^{l3}C$ values towards the unproductive period through the biomodification of the $\delta^{l3}C$ values in the food web, respiring preferentially and selectively $^{12}C$ atoms. Correspondingly, the increasing $\delta^{l5}N$ values in the intermediate-water trap are likely associated with a switch in source from diatom aggregates to some remains of zooplankton, because organic matter dominated by diatom may be more liable and prone to remineralization, leading to greater isotopic alteration. In particular, the tendency for abnormally high $\delta^{l5}N$ values in February seems to be enigmatic. A specific species dominancy during the production may be suggested as a possible and speculative reason.