• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• 제4권1호
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• pp.51-57
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• 2000

Changes in the proline accumulation of ten-day-old seedlings of Vigna angularis in response to NaCl treatment were monitored. The proline content increased gradually both with an increase in the exposure time to salt stress and in a concentration-dependent manner. The increased proline accumulation was stronger in the shoots than in the roots. The salt stress by itself resulted in a significant inhibition of the chlorophyll content. Pre-treatment with proline before salinization lasting 48 h did not significantly affect the endogenous proline level in the roots, in contrast, a considerable increase of proline was observed in the shoots. The application of exogenous proline to the seedlings increased the endogenous proline content and improved the root and shoot growth under saline conditions. Detached leaves also exhibited an increased proline level in response to the applied NaCl, however, at a lower magnitude than in the intact seedlings. The proline alleviated the inhibitory effect of the NaCl in a concentration-dependent manner, thereby suggesting that salinity is a strong inducer of proline accumulation. In addition, abscisic acid eliminated the inhibitory effect of the salt salinity, thereby indicating a protective role on salinity stress and a regulatory role in proline synthesis. Accordingly, it would appear that proline may be involved in salt tolerance.

• 한국물환경학회지
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• 제27권6호
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• pp.776-783
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• 2011

In a natural water body, a useful ecotechnology to reduce standing crops of phytoplankton is to strengthen the top-down force of zooplankton. However, the predation of fish for zooplankton can make the force weak. This study was conducted to find out the effect of fish on the grazing pressure of zooplankton in the mesocosms established in a eutrophic stream (Kyongan Stream) from October to November in 2010. In the corral with fish, chlorophyll a concentration increased, and a small size cladoceran Bosmina longirostris was dominant. In the corral without fish, chlorophyll a concentration decreased along with the domination of a large cladoceran Daphnia galeata and a large copepod Eudiaptomus japonicus. The size-selective predation of fish appeared to miniaturize the zooplankton community, to narrow their food-size spectrum, and to weaken the top-down force.

• Journal of Plant Biology
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• 제35권4호
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• pp.323-332
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• 1992

인천항 폐쇄 해양상태계에서 식물플랑크톤의 생물량과 일차생산력을 측정하기 위하여 1990년 8월부터 1991년 12월까지 시료를 채집, 분석하였다. 식물플랑크톤의 생물량을 chlorophyll-a로 분석한 결과 총 엽록소량은 $1.61-28.67\;\mu\textrm{g}$ Chl-a/l였는데 이 중 nanoplankton($2-20\;\mu\textrm{m}$)은 조사 시기와 정점에 따라 총 엽록소량의 19.0-82.3%를 차지하였고, picoplankton($0.2-2\;\mu\textrm{m}$)은 4.5-51.4%를 차지하였다. 한편, $^{14}C$ method를 이용한 식물플랑크톤에 일차생산력을 $49.4-4359.4\;mg\;C{\cdot}m^{-2}{\cdot}day^{-1}$로 측정되었는데, 이 중 미세플랑크톤($20\;\mu\textrm{m}$)의 기여율은 18.8-94.6%여서 세포 크기가 작은 개체군의 생물량과 생산력이 전체 식물플랑크톤 군집에 중요한 역할을 담당하고 있음을 알 수 있다. 식물플랑크톤 생물량의 월변호를 보면 3월에 1차 대발생이 일어났고 8월에 2차 대발생이 일어났다. 식물플랑크톤에 의한 실소요구량은 동계에 $0.7\;mg\;at-N{\cdot}m^{-2}{\cdot}day^{-1}$에서 하계에 $60.7\;mg\;at-N{\cdot}m^{-2}{\cdot}day^{-1}$로 증가하였고 질소계 영양염에 대한 회전시간(turnover time)은 동계에 149.9일에서 하계에 1.0일이여서 하계에 질소 이용율이 매우 빨라짐을 알 수 있었다. 동화수(assimilation number)는 하계에 증가하고 동계에 감소하는 경향을 보였다.

• Environmental Engineering Research
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• 제18권4호
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• pp.235-239
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• 2013

In the present investigation, the efficiency of Chlorella vulgaris (C. vulgaris) was evaluated for the removal of ammonia-nitrogen from wastewater. Eight different wastewater samples were prepared with varied amounts of $NH_4-N$ concentrations from 15.22 to 205.29 mg/L. Experiments were conducted at pH $7.5{\pm}0.3$, temperature $25^{\circ}C{\pm}1^{\circ}C$, light intensity $100{\mu}E/m^2/s$, and dark-light cycles of 8-16 hr continuously for 8 days. From the results, it was found that $NH_4-N$ was completely removed by C. vulgaris, when the initial concentration was between 5.22-25.24 mg/L. However, only 50% removal was obtained when the $NH_4-N$ concentration was 85.52 mg/L, which further decreased to less than 32% when the $NH_4-N$ concentration exceeded 105.43 mg/L. The further influence of nitrogen on chlorophyll was studied by various $NH_4-N$ concentrations. The maximal value of chlorophyll a (Chl a) content was found to be 19.21 mg/L for 65.79 mg/L $NH_4-N$ concentration, and the maximum specific $NH_4-N$ removal rate of 1.79 mg/mg Chl a/day was recorded at an $NH_4-N$ concentration of 85.52 mg/L. These findings demonstrate that C. vulgaris could potentially be employed for the removal of $NH_4-N$ from wastewater.

• ALGAE
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• 제39권3호
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• pp.187-205
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• 2024

Chlorella species of microalgae are utilized in the crop and food industries. The aim of this research was to investigate the metabolite profiles of Chlorella fusca for the first time and evaluate its biological properties. The two ion modes of UPLC-Q-TOF-MS/MS were used to identify a total of 62 components in the methanol extract of C. fusca, with 26 in the negative and 36 in the positive ion mode, including 10 identical ingredients. Fatty acids (negative mode) and combinations of chlorophyll and fatty acids (positive mode) were the most prevalent chemical structures, constituting over 80 and 70% of the total metabolites, respectively, followed by chlorophyll, polar lipids, carotenoids, and fatty alcohols. Moreover, this extract exhibited potent antioxidant and anti-aging benefits in decreasing order of potency at a concentration of 200 ㎍ mL^-1: tyrosinase inhibition (100%), ABTS radical scavenging (90%), elastase inhibition (88%), and DPPH radical scavenging (34%). Notably, this extract protected the mobility of DNA fragments up to 5 ㎍ mL^-1 (26%), with potential effects (> 60% at 200 ㎍ mL^-1). These findings suggest that C. fusca may be a promising candidate for applications related to its biological functions, owing to the high accumulation of fatty acids and chlorophyll derivatives.

• Journal of Ecology and Environment
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• 제42권1호
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• pp.1-11
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• 2018

Background: In the study, the effects of elevated $CO_2$ and temperature on the nitrogen content, carbon content, and C:N ratio of seven rare and endangered species (Quercus gilva, Hibiscus hambo, Paliurus ramosissimus, Cicuta virosa, Bupleurum latissimum, Viola raddeana, and Iris dichotoma) were examined under control (ambient $CO_2$ + ambient temperature) and treatment (elevated $CO_2$ + elevated temperature) for 3 years (May 2008 and June 2011). Results: Elevated $CO_2$ concentration and temperature result in a decline in leaf nitrogen content for three woody species in May 2009 and June 2011, while four herb species showed different responses to each other. The nitrogen content of B. latissimum and I. dichotoma decreased under treatment in either 2009 and 2011. The leaf nitrogen content of C. virosa and V. raddeana was not significantly affected by elevated $CO_2$ and temperature in 2009, but that of C. virosa increased and that V. raddeana decreased under the treatment in 2011. In 2009, it was found that there was no difference in carbon content in the leaves of the six species except for that of P. ramosissimus. On the other hand, while there was no difference in carbon content in the leaves of Q. gilva in the control and treatment in 2011, carbon content in the leaves of the remaining six species increased due to the rise of $CO_2$ concentration and temperature. The C:N ratio in the leaf of C. virosa grown in the treatment was lower in both 2009 and 2011 than that in the control. The C:N ratio in the leaf of V. raddeana decreased by 16.4% from the previous year, but increased by 28.9% in 2011. For the other five species, C:N ratios increased both in 2009 and 2011. In 2009 and 2011, chlorophyll contents in the leaves of Q. gilva and H. hamabo were higher in the treatment than those in the control. In the case of P. ramosissimus, the ratio was higher in the treatment than that in the control in 2009, but in 2011, the result was the opposite. Among four herb species, the chlorophyll contents in the leaves of C. virosa, V. raddeana, and I. dichotoma did not show any difference between gradients in 2009, but decreased due to the rise of $CO_2$ concentration and temperature in 2011. Leaf nitrogen and carbon contents, C:N ratio, and chlorophyll contents in the leaves of seven rare and endangered species of plant were found to be influenced by the rise and duration of $CO_2$ concentration and temperature, species, and interaction among those factors. Conclusions: The findings above seem to show that long-term rise of $CO_2$ concentration, and temperature causes changes in physiological responses of rare and endangered species of plant and the responses may be species-specific. In particular, woody species seem to be more sensitive to the rise of $CO_2$ concentration and temperature than herb species.

• 한국수산과학회지
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• 제27권6호
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• pp.727-732
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• 1994

식물플랑크톤의 엽록소 a 당 in vivo fluorescence 세기 (R)가 netplankton과 nanoplankton 사이에 차이가 있는지 남해에서 조사하였다. In vivo fluorescence (IVF)와 엽록소 a는 서로 다른 두 크기의 플랑크톤에서 자각 좋은 상관관계를 보였으나 비율 R은 netplankton과 nanoplankton 사이에 유의적으로 차이가 있었으며 nanoplankton의 R 값이 netplankton 보다 약 7배 높았다. 그러므로 IVF로 식물플랑크톤의 크기별 생물량을 측정할 때 R에 대한 식물플랑크톤 크기의 영향을 고려하여야한다.

• 대한원격탐사학회지
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• 제25권6호
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• pp.475-486
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• 2009

Harmful algal blooms (HAB) caused by the dominant species Cochlodinium polykrikoides (C. polykrikoides) appear in the South Sea of Korea and are particularly present in summer and fall seasons. Environmental factors such as water temperature, weather conditions (air temperature, cloud cover, sunshine, precipitation and wind) influence on the initiation and subsequent development of HAB. The purpose of this research was to study spatial and temporal variations of HAB in the Yeosu area using environmental (oceanic and meteorological) and satellite data. Chlorophyll-a concentrations were calculated using Sea-viewing Wide Field-of-view Sensor (SeaWiFS) images by an Ocean Chlorophyll 4 (OC4) algorithm, and HAB were estimated using the Red tide index Chlorophyll Algorithm (RCA). We also used the surface velocity of sequential satellite images applying the Maximum Cross Correlation method to detect chlorophyll-a movement. The results showed that the water temperature during HAB occurrences in August 2002-2008 was $19.4-30.2^{\circ}C$. In terms of the frequency of the mean of cell density of C. polykrikoides, the cell density of the HAB found at low (<300 cells/ml), medium (300-1000 cells/ml), and high (>1000 cells/ml) levels were 27.01%, 37.44%, and 35.55%, respectively. Meteorological data for 2002-2008 showed that the mean air temperature, precipitation, wind speed and direction, and sunshine duration were $22.39^{\circ}C$, 6.54 mm/day, 3.98 m/s (southwesterly), and 1-11.7 h, respectively. Our results suggest that HAB events in the Yeosu area can be triggered and extended by heavy precipitation and massive movement of HAB from the East China Sea. Satellite images data from July to October 2002-2006 showed that the OC4 algorithm generally estimated high chlorophyll-a concentration ($2-20\;mg/m^3$) throughout the coastal area, whereas the RCA estimated concentrations at $2-10\;mg/m^3$. The surface velocity of chlorophyll-a movement from sequential satellite images revealed the same patterns in the direction of the Tsushima Warm Current.

• Current Research on Agriculture and Life Sciences
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• 제6권
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• pp.19-24
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• 1988

주요(主要)잔디의 plug로 잔디포(圃) 조성시(造成時) 조도(照度)가 미치는 영향(影響)을 조사(調査)한 바 그 결과(結果)는 다음과 같다. Chewings fescue와 zoysia-82는 조도(照度) 감소(減少)에 따라 초장(草長)과 엽장(葉長)은 길었고 엽폭(葉幅)은 감소(減少)하였으나, red fescue는 이식(移植) 90일(日), 120일(日) 후(後) 조사시(調査時) 9%의 조도(照度)에서의 초장(草長)과 엽장(葉長)이 30%의 조도(照度)에서 보다 더 짧았다. 세 종(種) 모두 조도(照度)가 감소(減少)함에 따라 지표면(地表面) 피복율(被覆率)이 감소(減少)하였으며 각(各) 부위별(部位別) 건물중(乾物重)도 조도(照度)의 감소(減少)에 따라 가벼워졌다. Zoysia-82는 조도(照度)의 감소(減少)에 따라 엽록소(葉綠素) a, b, 및 총(總) 엽록소함량(葉綠素含量)이 증가(增加)하였으나, red fescue와 chewings fescue는 30%의 조도(照度)에서 엽록소함량(葉綠素含量)이 가장 많은 편이었고, 엽록소(葉綠素) a/b는 chewings fescue와 red fescue는 자연광(自然光)에서 낮았으나 zoysia-82는 30%의 조도(照度)에서 가장 낮았다. Chewings fescue와 red fescue의 분얼수는 조도(照度)가 감소(減少)할수록 감소(減少)하였다. zoysia-82의 절간장(節間長)은 30%, 자연광(自然光), 9% 조도(照度) 순(順)으로 길었고, 절간직경(節間直莖)은 조도(照度)의 감소(減少)에 따라 감소(減少)하였다.

• 대한원격탐사학회지
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• 제23권4호
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• pp.323-334
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• 2007

2001년부터 2004년까지 인천-제주 정기여객선을 이용하여 18회에 걸쳐 자동관측과 함께 20-30분 간격으로 40여개의 정점에서 해수를 채수하여 클로로필, 용존유기물과 부유퇴적물의 농도를 분석하였다. 연구의 목적은 채수된 해수를 직접 분석하여 서해 한반도 연안의 해수 환경의 공간적 시간적 변화를 모니터링 하는 것과 설치된 자동측정 센서가 신뢰성 있는 자료를 생산하는지 비교 분석하는 것이다. 18회에 걸친 서해 연안의 실시간 모니터링을 통하여 해수환경의 계절별 특성을 이해할 수 있었다. 클로로필의 경우, $0.1-6.0mg/m^3$ 정도의 분포를 보였으며 경기만이 다른 지역에 비해 높게 나타났다. 2004년 9월에는 경기만에서 $10mg/m^3$의 높은 값을 보였다. 용존유기물의 흡광 특성은 대부분은 $0.5m^{-1}$ 이하의 값 분포를 보였으나, 2001년 8-9월에 경기만과 목포 해역에서 높은 값을 보였으며, 2002년과 2003년은 다른 시기에 비해 계절별 변화가 적었다. 부유퇴적물의 경우, 대부분은 $20g/m^3$ 미만의 값을 보였으나 경기만과 목포 주변의 남쪽 해안은 농도가 모든 계절에서 높게 나타났으며 특히 가을. 겨울철에 가장 높은 값을 나타냈다. 황해중부 해역은 대부분 $10g/m^3$ 미만의 값을 보였다. YSI 센서의 클로로필 값은 신뢰도가 낮게 나타나 사용하기 어려웠으며 부유퇴적물의 농도는 4번의 조사시기에 대해 $R^2$ 값이 0.77 정도의 값을 보였다. 부유퇴적물과 클로로필의 자동관측을 위해서는 단일 센서인 McVan과 ChelSea 사의 것이 우수한 것으로 분석되었다. 현장조사에 의한 부유퇴적물 분포는 비슷한 시기에 얻어진 SeaWiFS 분석 결과와 공간적인 분포는 잘 일치하였으나 농도 값에서는 다소 차이를 보였다.