http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
환경조건에 따른 Aphanizomenon flos-aquae (Cyanophyceae) 균주의 성장 반응 및 독소 생성
류희성,신라영,이정호,Ryu, Hui-Seong,Shin, Ra-Young,Lee, Jung-Ho 한국물환경학회 2017 한국물환경학회지 Vol.33 No.5
The purpose of this study is to investigate growth response and toxigenicity under various temperature and nutritional conditions, in order to understand the physioecological characteristics of Aphanizomenon flos-aquae, which is a bloom-forming cyanobacterium in the Nakdong River. The strain was inoculated into media under combinations of four temperatures (4, 12, 21, $30^{\circ}C$) and three nutrients (modified CB medium, P-depleted CB medium, N-depleted CB medium) for 28 days. The algae-inhibition tests were performed to assess the potential allelopathic effects of the strains' filtrates on the growth of four algae strains (Microcystis aeruginosa, Aulacoseria ambigua f. spiralis, Aphanizomenon flos-aquae, Scenedesmus obliquus). Toxin production of a strain was measured by Enzyme-Linked ImmunoSolbent Assay (ELISA). The optimal growth temperature (Topt) of strains was $19.9^{\circ}C$ ($18.3-21.2^{\circ}C$), and the temperature range for growth was from $-0.3^{\circ}C$ to $34.3^{\circ}C$. Specific growth rate (${\mu}$) in modified CB medium varied from 0.10 to $0.16day^{-1}$, and the maximum growth rate (${\mu}_{max}$) was $0.17day^{-1}$. Although growth curves under N-existed and N-depleted conditions were almost the same, growth under N-depleted condition was relatively slowed (${\mu}=0.09$ to $0.14day^{-1}$), with a decreased maximum cell density. However, growth under the P-depleted condition was restricted for all temperatures, Two stains of Aphanizomenon flos-aquae were confirmed as not producing toxins, because saxitoxin and cylindrospermopsin were not detected by ELISA. The exudates or filtrates from the Aphanizomenon flos-aquae (DGUC003) resulted in significant inhibition of algal growth on the Aulacoseira ambigua f. spiralis (DGUD001) and Aphanizomenon flos-aquae (DGUC001) (p < 0.01).
geoA 유전자를 이용한 사상형 남조류(Nostocales, Oscillatoriales)의 Geosmin 생성능 검출
류희성 ( Hui-seong Ryu ),신라영 ( Ra-young Shin ),서경애 ( Kyung-ae Seo ),이정호 ( Jung-ho Lee ),김경현 ( Kyunghyun Kim ) 한국물환경학회 2018 한국물환경학회지 Vol.34 No.6
Geosmin is volatile metabolites produced by a range of filamentous cyanobacteria which causes taste and odor problems in drinking water. Molecular ecological methods which target biosynthetic genes (geoA) are widely adopted to detect geosmin-producing cyanobacteria. The aim of this study was to investigate the potential production capability of 8 strains isolated from the Nakdong River. Ultimately, a suggestion for a genetical monitoring tool for the identification of geosmin producers in domestic waters was to be made. Geosmin was detected using solid phase microextraction gas chromatography mass spectrometry (SPME GC-MS) in two strains of Dolichospermum plactonicum (DGUC006, DGUC012) that were cultured for 28 day. The highest concentrations during the experiment period was 17,535 ngL<sup>-1</sup> and 14,311 ngL<sup>-1</sup> respectively. Additionally, geoA genes were amplified using two primers (geo78F/971R and geo78F/982R) from strains shown to produce geosmin, while amplification products were not detected in any of non-producing strains. PCR product (766 bp) was slightly shorter than the expected size for geosmin producers. According to the BLAST analysis, amplified genes were at nucleotide level with Anabaena ucrainica (HQ404996, HQ404997), Dolichospermum planctonicum (KM13400) and Dolichospermum ucrainicum (MF996872) between 99 ~ 100 %. Both strains were thus confirmed as potential geosmin-producing species. We concluded that the molecular method of analysis was a useful tool for monitoring potential cyanobacterial producers of geosmin.
낙동강 보 구간에서 남조류의 천이 및 Dolichospermum 속(Nostocales, Cyanophyceae)의 분류학적 고찰
류희성 ( Hui-seong Ryu ),신라영 ( Ra-young Shin ),서경애 ( Kyung-ae Seo ),이정호 ( Jung-ho Lee ),김경현 ( Kyunghyun Kim ) 한국물환경학회 2018 한국물환경학회지 Vol.34 No.5
Freshwater cyanobacterial genus Dolichospermum is one of the most commonly spotted types of phytoplankton, whereas a limited number of studies on morphology of Dolichospermum spp. have been performed in South Korea. The purpose of this study is to investigate the succession pattern of cyanobacteria after weir construction, as well as morphological characteristics of Dolichospermum spp. from natural samples collected in the weir regions of Nakdong River. A total of 31 cyanobacterial taxa observed in this study were classified as belonging to 15 genera, 5 families, and 3 orders. Among them, morphological characteristics in the four species were classified into genus Dolichospermum, for most of the planktic former members of the genus Anabaena, were observed through light microscopy. Water bloom frequently occurred in the middle region of Nakdong River, the maximum number of cyanobacterial species appeared in the lower region of Nakdong River. The appearance of order Chrooccocales was only observed during summer when population density of Microcystis aeruginosa reached an annual peak. In contrast, filamentous cyanobacteria was observed throughout the whole year, even if when water temperature was lower than 5 °C. It implied that the low-temperature-adapted filamentous cyanobacteria can grow in a range of water temperatures. Coil diameter of D. crassum from natural samples was 75 ~ 140 μm (ave. = 91.3 μm; n = 94), slightly larger than those reported by previous studies. Dolichospemum smithii (Komàrek) Wacklin et al. 2009, was described for the first time in Nakdong River.
낙동강 상류 수역에서 남조류 발생과 천이패턴 - Aphanizomenon 속을 중심으로 -
류희성 ( Hui Seong Ryu ),박혜경 ( Hae Kyung Park ),이혜진 ( Hae Jin Lee ),신라영 ( Ra Young Shin ),천세억 ( Se Uk Cheon ) 한국물환경학회 2016 한국물환경학회지 Vol.32 No.1
This study investigated the occurrences and succession patterns of harmful cyanobacteria, as well as environmental factors, during a 3-year period (September 2012 to August 2015) in the upper region of the Nakdong River around Sangju weir. A total of 27 cyanobacterial taxa were observed in this study, and classified into 26 species and 1 variety belonging to 11 genera, 5 families, and 3 orders. Cell density ranged from 24 to 42,001 cells/ml, with a geometric mean of 33 cells/ml, during the survey period. The dominant orders differed depending on the survey year; order Oscillatoriales in 2013, Chroococcales in 2014 and Nostocales in 2015. An Aphanizomenon bloom occurred in June 2015 at which time the highest cell density of 36,873 cells/ml was detected in the upper region of the Nakdong River, where as the Aphanizomenon spp. cell density (190-1,704 cells/ml) had been low prior to that time. An Aphanizomenon bloom also occurred at around the same time downstream in the Young River, a major inflow branch of the Nakdong River. The Aphanizomenon cell density along the Nakdong River increased markedly after joining of the YoungRiver, indicating that the Aphanizomenon bloom in the YoungRiver caused a bloom in the Nakdong River. Meteorological and environmental parameters, such as very low precipitation, higher water temperature, pH, and TP concentration, and lower TN/TP ratio, in May and June of 2015 than in 2013 and 2014 exerted marked effects on the Aphanizomenon bloom in June 2015 in the Young River.
하천에서 중금속 아연(Zn) 유입이 부착규조의 종조성과 형태 변이에 미치는 영향
신라영,류희성,이정호,Shin, Ra-Young,Ryu, Hui-Seong,Lee, Jung-Ho 한국물환경학회 2017 한국물환경학회지 Vol.33 No.4
The purpose of this study is to understand the changes on species composition of the epilithic diatoms and the appearance of morphological abnormalities in the upper region of the Nakdong River where heavy metal inflow is observed. The samples were collected once a week for a month of September 2016 from selecting 7 sampling stations. The heavy metals of cadmium (Cd) and arsenic (As) were not detected during the survey period, but zinc (Zn) was detected in st.4 - st.6 with the range of $0.015{\sim}0.188mg\;L^{-1}$. Metal sensitive species such as Achnanthes convergens, Cocconeis placentula, Cocconeis placentula var. euglypta, Cocconeis placentula var. lineata showed high dominance in st.1 - st.3, st.7. However, metal tolerant species such as Nitzschia palea, Achnanthes minutissima showed high dominance in st.4 - st.6. It is concluded that heavy metal inflow directly affects the changes in species composition of epilithic diatoms. As a result of CCA, the characteristics of the sampling sites were divided into 3 groups. Group 1 was represented the non-detected Zn sites with C. placentula, C. placentula var. euglypta, C. placentula var. lineata. Group 2 was showed the detected Zn sites with Navicula minima and Nitzschia palea. Group 3 was included st.3 - st.7 on 4th week that was stabilized the community structure. Total 8 taxa of abnormal frustules observed. This occurrence of abnormal frustules reflected the temporal and quantitative indicators of heavy metal pollution, in particular, it was confirmed that genus Fragilaria, which has a high abnormality according to heavy metal pollution, can be used as an indicator species.
대형 2행정 디젤엔진의 EGR 시스템에 의한 NOx 배출물 저감 특성
배명환(Myung-whan Bae),류지호(JiHo Ryu),김성완(SeongWan Kim),박희성(Hui-seong Park) 대한기계학회 2019 대한기계학회 춘추학술대회 Vol.2019 No.11
The purpose of this study is to investigate whether the NOX emissions measured by applying the EGR system in a large two-stroke diesel engine satisfy the exhaust emissions regulation of Tier III. In the applied Miller cycle, the NOX emissions met the emissions regulatory value of Tier II above the engine load of 75%, but did not meet Tier III at any engine loads. In the case of the applied EGR system, the NOX emissions slightly exceeded the regulatory limit value of Tier III below the engine load of 50%, but were satisfied when the engine load exceeded 50%.
보문 : 담수산 어류 꺽지 (Coreoperca herzi)의 자원 평가 및 관리 방안 연구: 섬진강 중,상류 수계에서 꺽지의 자원량 및 잠재생산량 추정(2)
장성현 ( Sung Hyun Jang ),류희성 ( Hui Seong Ryu ),이정호 ( Jung Ho Lee ) 한국하천호수학회(구 한국육수학회) 2011 생태와 환경 Vol.44 No.2
The study sought to determine the efficient management of Korean aucha perch by estimating the potential yield (PY), which means the maximum sustainable yield (MSY) based on the optimal stock, in the mid-upper region of the Seomjin River watershed from August 2008 to April 2009. The stock assessment was conducted by the swept area method and PY was estimated by a modified fisheries management system based on the allowable biological catch. Also, the yield-per-recruit analysis (Beverton and Holt, 1957) was used to review the efficient management of resource, Coreoperca herzi. The age at first capture (t(c)) was 1.464 age and converted body length was 7.8 cm. Concerning current fishing intensities, the instantaneous coefficient of fishing mortality (F) was estimated to be 0.061 year-1; yield-per-recruit analysis estimated the current yield per recruit as 4.124 g with F and t(c). The fishing mortality of Allowable Biological Catch (F(ABC)) based on the current t(c) and F was estimated to be 0.401 year-1, therefore, the optimum. fishing intensities could be achieved at the higher fishing intensity for Coreoperca herzi. The calculated annual stock of Coreoperca herzi was 3,048 kg, the potential yield was estimated to be 861 kg with t(c) and F(ABC) at the fixed current level. Using yield-per-recruit analysis, if F and t(c) were set at 0.643 year-1 and 3 age, respectively, the yield per recruit would be predicted to increase 3.4-fold, from 4.12 g to 13.84 g.