• ALGAE
• /
• 제18권2호
• /
• pp.129-134
• /
• 2003

In order to examine the effects of deep seawater (mesopelagic water in the broad sense) on the growth of macroalgae, the growth and nutrient uptake (nitrate and phosphate) of Ulva sp. (Ulvophyceae, Chlorophyta) were investigated by cultivation in deep seawater (taken from 687 m depth at Yaizu, central Japan, in August 2001), surface seawater (taken from 24 m depth), and a combination of the two. Culture experiments were carried out in a continuous water supply system and an intermittent water supply system, in which aerated 500-mL flasks with 4 discs of Ulva sp. (cut sections of ca. 2 $cm_2$) were cultured at 20$^{\circ}C$ water temperature, 100 $\mu$mol photons $m^{-2}{\cdot}s^{-1}$ light intensity, and a 14:10 light:dark cycle. Nutrient uptake by Ulva sp. was high in all seawater media in both culture systems. The frond area, dry weight, chlorophyll a content, dry weight per unit area, and chlorophyll a content per unit area of Ulva sp. at the end of the experimental period were the highest in deep seawater and the lowest in surface seawater in both culture systems. These values, except for dry weight per unit area and chlorophyll a content per unit area, for each seawater media in the intermittent water supply system were higher than those in the continuous water supply system. We conclude that not only deep seawater as the culture medium but also the seawater supply system is important for effective cultivation of macroalgae.

• 대한의생명과학회지
• /
• 제22권4호
• /
• pp.150-159
• /
• 2016

Knowledge of the distribution and biodiversity of environmental bacteria and the ecosystem that influences them is crucial for predicting an ecosystem. However, bacterial culture methods can only analyze approximately 0.1% of the existing microorganisms, those that are readily cultured under laboratory conditions. By contrast, next-generation sequencing (NGS) has generally been known to obtain more diverse profiling of bacterial composition. We compared the bacterial communities using both a culture-dependent (MALDI-TOF) and culture-independent (NGS) methods. Environmental specimens were obtained from both freshwater and seawater. Water samples were also analyzed by both pyrosequencing and MiSeq sequencing, in order to select one NGS platform which could analyze comparatively more diverse microbiota. Bacterial distribution analyzed with MALDI-TOF showed no difference between the microbiota of freshwater and seawater, whereas the results analyzed with NGS distinguished between the two. The diversity indexes of MiSeq sequencing were higher than for Pyrosequencing. This indicated that MiSeq sequencing is capable of analyzing a comparatively wider diversity of bacteria. The genus of Flavobacterium and Planktophila were identified as being unique to freshwater, whereas EU801223 and OM43 were found in the seawater. Difference between the bacterial composition of the freshwater and seawater environments was identified by MiSeq sequencing analysis.

• ALGAE
• /
• 제17권2호
• /
• pp.127-133
• /
• 2002

The red seaweed Eucheuma serra is a high yielding source of lectins. The plants were collected from a depth of 5-6 meters and cultured in the laboratory, field and deep seawater. A Daily Growht Rate (DGR) of 3.5% was observed at 18℃ with a low light of 30μmol photon $ m^{-2} · s^{_1}$ in the laboratory. When the plants were cultured in the field at different depths during winter onths of December and January, best growth was observed at 1 m depth and a DGR of 2.14±0.04% was recorded. The plants grown in the tank with a continuous supply of deep seawater showed a DGR of 8.2% The results indicate that E. serra can be cultivated in large scale both in deep seawater in the tank and in the field for the extraction of lectins at a commercial scale.

• 한국양식학회지
• /
• 제6권4호
• /
• pp.311-321
• /
• 1993

Ammonia accumulation is regarded as the limiting factor of the first priority in water qualities of aquatic culture systems. Nitrification efficiency and characteristics in seawater were evaluated using Rotating Biological Contactor (RBC) process as a part of the recycling water treatment facilities for marine fish culture system. Ammonia removal efficiency regarded 99.7 to $83.7\%$ at the ammonia surface loading rates of 48 to $393 mg/m^2$ -day. RBC process was able to withstand to the fluctuation of influent ammonia concentrations and loading and produced the stable effluent. The mathematical model on the fixed-film biological reactor developed by Kornegay seemed to be suitable to RBC process kinetic evaluation for the recycling water treatment of the marine fish culture system. Area capacity constant (P) and half-velocity constant (Ks) in the model were 0.188g/m^2$-day and 1.25mg/l, respectively.

• 한국양식학회:학술대회논문집
• /
• 한국양식학회 2003년도 추계학술발표대회 논문요약집
• /
• pp.125-125
• /
• 2003

Recirculating aquaculture systems consist of different treatment compartments that maintain water quality within the ranges of commonly recommended for fish culture. This paper presents the common considerations in designing different treatment compartments as well as the engineering criteria in designing closed recirculating aquaculture system including a circular tank for fish culture, a sedimentation basin and a foam fractionator for solids removal, two styrofoam bead filters for TAN removal, a sand filter for nitrate removal, and aerators. The main purpose is to outline a common procedure in designing of closed recirculating aquaculture system for marine fish culture.

• 한국식품저장유통학회지
• /
• 제10권3호
• /
• pp.417-420
• /
• 2003

해양 심층수 첨가에 따른 효모 발효력과 심층수 첨가 최적 농도를 알아보기 위하여 효모균주 9종에 대하여 증식을 조사하였다. 효모균주는 Saccharomyces cerevisiae 10호, 11호, 12호, 901, RCY, Sacch.cerwisiae ktwef DJ97, Saccharomyces cerevisiae YJK, JK99, CMY-28 등이었으며, 해양 심층수는 경도 250, 500, 1000으로 조절하였고 대조군과 함께 증식력을 측정하였다 Saccharomyces cerevisiae 12호 균주가 심층수 경도 500인 시험군에서 증식력도 높았으며, Sacch. cerevisiae 901에서는 경도 1000인 시험군이 대조군에 비해 증식력이 높게 나타나 효모균주의 종류와 심층수의 첨가량에 따라 적응력이 강한 균주가 있었다. 당농도와 심층수 첨가량에 따른 Sacch. cerevisiae kluyevery DJ97의 발효력은 심층수 경도 200의 당 10％ 첨가군에서 가장 잘 증식하였다.

• 한국패류학회지
• /
• 제32권3호
• /
• pp.203-209
• /
• 2016

축제식 양식어장에서 홍합 치패의 중간육성 가능성을 확인하기 위해 2014년 9월부터 2015년 4월까지 홍합 치패의 성장과 생존율을 측정하였다. 또한 수온, 염분, 용존산소, pH, 용존무기질소 (DIN), 용존무기인 (DIP), 엽록소-a 및 식물플랑크톤의 현존량을 동시에 분석하였다. 수온과 염분의 범위는 각각 $4.0-23.4^{\circ}C$, 18.8-25.2 psu 로써, 일반적으로 보고된 적정 수준보다 낮았다. 매월 측정된 홍합 치패의 생존율은 모든 실험구에서 90% 이상을 기록하였다. 엽록소-a 농도와 식물플랑크톤의 현존량은 높게 나타났고, 주요 우점종은 은편모류와 미소편모류이었다. 이들 우점종은 이매패류 유생의 좋은 먹이가 될 것으로 판단된다. 축제식 양식어장의 저층에 채롱 당 100 개체($2,700ind.\;m^{-2}$) 의 밀도로 수용한 실험구에서 가장 높은 성장 ($7.63{\pm}4.65mm$) 을 보였으나, 채롱 당 200 개체 (5,400 개체 $m^{-2}$) 이하를 수용한 실험구 간에는 유의적인 차이가 없었다. 적절한 관리가 이루어진다면 축제식 양식어장은 이매패류 치패의 중간 육성을 위한 대안적 어장이라고 판단된다.

• 한국미생물·생명공학회지
• /
• 제34권2호
• /
• pp.143-149
• /
• 2006

담수 혹은 해수에서 배양한 S. platensis의 추출조건에 따른 수율을 비교하기 위해 60$^{\circ}C$와 100$^{\circ}C$에서 물과 에탄올을 이용하여 추출하여 추출 수율을 비교한 결과 해수 S. platensis가 약 3% 정도 높은 추출 수율을 나타내었다. 그리고 각 추출물의 정상세포에 대한 세포 독성을 살펴보기 위하여 인간 정상 신장 세포(HEK293)를 이용하였으며, 모든 시료에서 1.0 mg/ml의 농도에서 26%이하의 비교적 낮은세포독성을 나타내었고, 그 중 해수 S. piatensis가 담수 S. piatensis보다 약 5% 정도 낮은 세포독성을 나타내었다. 그리고 암세포에 대한 암세포 생육 억제 활성을 측정한 결과 4가지 암세포 주인 폐암세포(A459)와 위암세포(AGS), 유방암세포(MCF-7)와 간암세포(Hep3B)에 대해 모든 추출물에 대해 1.0 mg/ml의 농도에서 70%이상의 높은 암세포 생육억제 효과를 나타내었고, 그 중 해수 S. platensis의 60$^{\circ}C$물 추출물에서 80%이상으로 가장 높은 암세포 생육 억제 효과를 나타내었다. 선택적 사멸도는 모든 암세포에서 1.5 이상으로 나타나 암세포에 대해 선택적으로 사멸시키는 것으로 나타났다. 담수 혹은 해수를 사용하여 배양한 경우 해수 S. platensis가 추출 수율뿐만 아니라 정상세포에 대한 세포독성 및 암세포 생육 억제 활성에서 높은 효과를 나타내었다. 인간 전골수세포인 HL-60세포를 이용한 세포분화도를 측정한 결과 60$^{\circ}C$에서 물을 이용하여 추출한 해수 S. platensis에서 담수 S. platensis보다 5일째 약 20% 정도의 높은 세포 분화 활성을 나타내었다.

• 한국수산과학회지
• /
• 제43권6호
• /
• pp.705-714
• /
• 2010

The residual oil concentrations in seawater and sediments were investigated along the Taean coast of Korea, following the Hebei Spirit oil spill, which occurred on 7 December 2007. The oil concentration in seawater ranged from 0.059 to $0.866\;{\mu}g/L$ for the tidal flat culture grounds and from 0.016 to $0.943\;{\mu}g/L$ in the fish cage areas in 2008. These were dominated by the seawater temperature relationship. Polycyclic aromatic hydrocarbons (PAHs) in sediments were also analyzed and the concentrations ranged from 3.4 to 509.7 ng/g dry weight. The average PAH level was higher in seawater from the Sinduri area than the Padori area, while the average PAH level in sediments was higher in Padori. The diagnostic ratio of PAHs was investigated to determine the origins of the PAHs. The PAHs in the Seongam area, which was not affected by the oil spill, are of pyrolytic origin, while the PAHs in Padori and Sinduri were of petrogenic origin. The residual oils in the areas affected by the oil spill tended to decrease over time, except in summer. The oils in pore water remained 6- to 16-fold higher, as compared to the seawater overlying the tidal flat, implying that residual oils will continue to influence the affected region for the foreseeable future.

• 한국발생생물학회지:발생과생식
• /
• 제24권3호
• /
• pp.215-224
• /
• 2020

Seawater adaptability of steelhead trout increases along with the increase in the size of the fish, independent of parr-smolt transformation. Three 96 h seawater challenge tests were conducted to determine the size at which seawater adaptability of steelhead trout develops. Plasma Na⁺ and Cl^- levels, moisture content, gill Na⁺/K⁺ ATPase activity, and mortality during the 96 h after direct transfer to seawater (32 ppt) were determined. Plasma Na⁺ and Cl^- levels in 50 g fish continuously increased during the 96 h after the transfer to seawater (p<0.05), but the levels in 100 and 150 g fish leveled off after 24 h (p<0.05). Both 100 and 150 g size steelhead trout maintained muscle moisture content (%) better than 50 g size fish (p<0.05). Gill Na⁺/K⁺ ATPase activity in the 100 g size group increased in a time-dependent manner after transfer to seawater (p<0.05), whereas activity in the 50 and 150 g sizes did not increase (p>0.05), for which a possible explanation was discussed. A mere 2.6% mortality in both the 50 and 150 g size groups was observed. In conclusion, the current results indicate that 50 g size steelhead trout did not show development of a high level of hypoosmoregulatory capacity, whereas fish in the 100 and 150 g size groups showed a high level in our experimental conditions. Therefore, the steelhead trout larger than a 100 g size is recommended for transfer to seawater culture.