• 한국수산과학회지
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• 제52권4호
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• pp.374-381
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• 2019

This study was conducted to examine a mixture of plant protein sources as a fish meal (FM) substitute. Two feeding trials were carried out using similar dietary formulations but different FM levels. In Experiments 1 and 2, the basal diets were formulated to contain 65% and 60% of FM, respectively. The other five diets were formulated replacing FM by 10, 15, 20, 25 and 30% with a mixture of soybean meal, wheat gluten and soy protein concentrate. Three synthetic amino acids (lysine, threonine and methionine) were added to the test diet. Groups of fish in experiment 1 ($6.76{\pm}0.03g$) and experiment 2 ($32.5{\pm}0.1g$) were fed one of the experimental diets for 7 and 9 weeks, respectively. Each experiment was carried out in triplicate. There were no significant differences among groups in terms of growth performance, feed utilization, survival or hematological parameters in either experiment. The results indicated that a mixture of soybean meal, wheat gluten and soy protein concentrate, supplemented with three synthetic amino acid, can replace fish meal by up to 30% in diets for juvenile olive flounder.

• 한국수산과학회지
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• 제54권3호
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• pp.350-357
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• 2021

This study aimed to evaluate how fish meal (FM) replacement in diets with a mixture of animal and plant protein sources affect growth performance, feed utilization, hematological parameters and innate immunity of red seabream Pagrus major. A control FM diet was formulated to contain 65% FM (Con). Two other diets were prepared replacing FM in the control diet with a mixture of protein sources (wheat gluten, soy-protein concentrate, tankage meal, and poultry by-product meal) by 30 and 40% (FM30 and FM40, respectively). Total 300 red seabream (body weight, 77.6±0.3g) were distributed to 12 tanks (300 L) in 4 replicates per diet. The fish were fed the diets to apparent satiation for 19 weeks. After the feeding trial, no significant differences could be observed in growth performance, feed utilization, hematological parameters, innate immunity, and survivals among all the dietary treatments. This long-term feeding trial at low water temperature (13.8-17.5℃) indicates that a proper mixture ratio of wheat gluten, soy protein concentrate, tankage meal, and poultry by-product meal can replace FM up to 40% in red seabream diets.

• 해양환경안전학회지
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• 제26권6호
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• pp.732-741
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• 2020

최근 환경규제가 강화됨에 따라 액화천연가스(Liquefied Natural Gas)를 이용하여 전력을 생산해내는 신규발전설비인 부유식 LNG 발전설비(floating LNG power plant)가 개발되고 있다. 부유식 LNG 발전설비는 운용 시 증발가스가 발생하고 이를 제거하거나 회수할 수 있는 시스템의 설계가 필요하다. 그러나 해양플랜트는 해상요건에 따라 설계가 상이하고, 부유식 LNG 발전설비의 설계 전 시행착오를 줄이기 위해 지속적으로 수정이 가능한 BOG 회수시스템 공정모사 모델이 필요하다. 따라서 본 연구에서는 상용공정시뮬레이션 프로그램을 통해 부유식 LNG 발전설비에 적합한 모델을 모델링하고자 냉매사용 유무에 따라 서로 다른 BOG(Boil-Off Gas) 회수시스템을 모델링하여 BOG의 회수율과 액화점을 비교 및 분석하였으며, 그 결과 질소냉매를 사용한 BOG 회수시스템 모델을 부유식 LNG 발전설비용 BOG 회수시스템 모델로 제안하고자 한다.

• Journal of Plant Biology
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• 제29권3호
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• pp.175-183
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• 1986

Marine algal flora and intertidal vegetation around Samchonpo power plant, south coast of Korea, were investigated at three sites, specially referred to the seasonal variation of the species from April to October, 1982. A total of 84 species were identified; 8 green, 19 brown and 57 red algae. Among three sampling sites investigated, 65 species were collected at the first site located in front of the power plant, 66 at the second site, Namildae beach, and 61 at the third, Sinsudo, respectively. The algal vegetation at the first site was dominated in cover by Sargassum thunbergii and Ulva pertusa in April, Corallina spp. Ulva pertusa in July, and Chondria crassicaulis and Ulva pertusa in October. At the second site, it was dominated in cover by Sargassum thunbergii, Gigartina tenella and Ulva pertusa in April, Sargassum thunbergii and Ulva pertusa in July, and Chondria crassicaulis and Ulva pertusa in October, whereas at the third site Sargassum thunbergii and Ulva pertusa in April, and Chondria crassicaulis in October, respectively. The biomass among three investigated sites showed 2,360 g-fresh wt/$m^2$ on an average; 283 g-dry wt/$m^2$ at the first, 277 g-dry wt/$m^2$ at the second, and 256 g-dry wt/$m^2$ at the third site, respectively.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2022년도 추계학술대회
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• pp.31-31
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• 2022

Plant-derived antioxidants are used as a healthy diet and are known to inhibit various human diseases. In this study, we investigated free radical scavenging and antioxidant activity of extracts from three plants (Ammannia multiflora, Ammannia coccinea and Salix gracilistyla) with the most DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity from 196 plant extracts inhabiting along Nakdong River in Republic of Korea. The three extracts also have strong total antioxidant activity. Moreover, the extracts inhibited hydrogen peroxide (H₂O₂)-induced reactive oxygen species production and depolarized mitochondrial membrane potential in RAW264.7 macrophages. In zebrafish larvae, 2',7'-dichlorodihydrofluorescein diacetate (DCFDA) fluorescent intensity, induced by H₂O₂, was markedly reduced by the extracts of A. multiflora, A. coccinea and S. gracilistyla. Meanwhile, the extracts were upregulated Nrf2 and HO-1 expression, and an HO-1 inhibitor reversed the extract-induced oxidative responses both in vivo and in vitro. The data suggest that the extracts of A. multiflora, A. coccinea, and S. gracilistyla exert potential free radical scavenging and antioxidant capacities both in vivo and in vitro by activating the Nrf2/HO-1 signaling pathway.

• Journal of Plant Biotechnology
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• 제2권3호
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• pp.157-163
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• 2000

Optimization of chemicals in the large scale sea water medium and inoculum for biomass and natural colourants production in the marine cyanobacteria, Phomidium tenue BDU 46241 (phycoerythrin producer) and P.valderianum BDU 30501 (phycocyanin producer) was carried out by experiments in L8 orthogonal array. Mathematical analysis revealed the significance of these factors. The factor(s) that critically control the yield varied with the organism and the end-product further, the desirable level of these factors between the normal and a higher level tested was identified and improved media were evolved. In both cyanobacteria, higher level of $K_2$$HPO_4$, $NaNO_3$ and inoculum with normal level of ferric ammonium citrate was found to be desirable for biomass production and additionally, higher level of $MgSO_4$ for pigment production. The level of other factors varied with the organism and the end-product. Confirmation experiments showed that the clues obtained based on mathematical experimentation are valid. In P.tenue, the medium optimized for biomass production increased the yield of biomass by 495% and the medium optimized for phycoerythrin production increased the yield of biomass by 408% with 30% increase in phycoerythrin content of the biomass. Similarly in P.valderianum, the medium optimized for biomass production increased the yield of biomass by 224% and the medium optimized for phycocyanin production increased the yield of biomass by 143% with 44% increase in phycocyanin content of the biomass.

• 한국수산과학회지
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• 제46권4호
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• pp.437-444
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• 2013

Eight fecal sterols were analyzed in surface sediments collected from shellfish farming areas in Yeoja Bay and Gangjin Bay, Korea, to evaluate sewage-derived fecal pollution. The concentrations of coprostanol, a good marker of sewage-derived organic contamination, in sediments were in the range of 10-530 ng/g-dry in Yeoja Bay, and 10-190 ng/g-dry in Gangjin Bay. Coprostanol levels were markedly higher in the inner bay than in the outer bay. These levels were lower than those reported in urbanized bays in Korea, however, they were comparable to levels in other shellfish farming areas including Gamak Bay. A multivariate analysis of the ratios of other sterols suggested that the sterols originated from sewage and plankton/benthos. Sewage was the dominant source at stations located close to the river mouth and wastewater treatment plant (WWTP) outfalls, and plankton/benthos was the primary source in the outer bay. These results suggest that management of point sources, e.g., WWTP as well as non-point sources, e.g., riverine inputs is important for improving the water quality in Yeoja Bay and Gangjin Bay.

• Fisheries and Aquatic Sciences
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• 제10권4호
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• pp.205-214
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• 2007

Surface water and sediment samples collected from the Mokpo coast of Korea were analyzed for molecular markers of organic municipal wastewaters, i.e., 11 fecal sterols including coprostanol (Cop) and nonylphenolic compounds (NPs), to characterize the main routes of these wastewaters to the coast and to assess contamination levels. Concentrations of Cop ranged from 94 to 7,568 ng/L in surface water and from 43 to 38,108 ng/g dry weight in sediments. Concentrations of NPs [nonylphenol (NP) and nonylphenol mono- and di-ethoxylates ($NP_{1-2}EOs$)] ranged from 123 to 4,729 ng/L in surface water and from 4 to 2,119 ng/ng dry weight in sediments. The levels of these compounds were much higher at stations near the rivers that pass through the urban center of Mokpo and the outfall of the wastewater treatment plant (WWTP). The spatial distribution of Cop levels was statistically similar to that of NPs (r=0.809 and 0.982 in surface water and sediments, respectively), indicating that these compounds may have similar discharge points, transport, mixing, and deposition in the study area. These results suggest that considerable amounts of organic wastewater compounds are discharged through rivers and WWTP effluent to the Mokpo coast.

• ALGAE
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• 제20권3호
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• pp.217-224
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• 2005

The species composition and biomass of marine algae at the discharge canals of three (Gori, Wolseong and Uljin) nuclear power plants on the east coast of Korea were investigated seasonally from February 1992 to October 2000. As a result, 103-107 species of marine algae were found at the discharge canals during the past nine years. In general, algal communities established at the discharge canals were less diverse than those at the intake canals and control sites. 43 species (6 blue-green, 9 green, 10 brown and 18 red algae) of marine algae occurred more than 1/6 frequency and thus can be categorized as warm tolerant species. Among these, two green (Urospora penicilliformis, Cladophora albida), four brown (Sphacelaria divaricata, S. rigidula, Sargassum coreanum, S. fulvellum) and four red algae (Stylonema alsidii, Bangia atropurpurea, Hypnea charoides, Chondria crassicaulis) are recorded as warm tolerant marine algae for the first time in Korea during this study. Enteromorpha compressa, Padina arborescens, Amphiroa zonata and Ahnfeltiopsis flabelliformis were common species found more than 50% frequency at the discharge canals of all three nuclear power plants investigated. Dominant species in biomass were Padina arborescens and Amphiroa zonata. Results showed that, as a whole, the red algae appeared as predominant algal group at the discharge canals of all three nuclear power plants on the east coast of Korea. However, the biomass proportion of dominant algae at the discharge canals of each nuclear power plant varied over the year during the past nine years.

• Fisheries and Aquatic Sciences
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• 제13권4호
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• pp.284-293
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• 2010

To reduce anti-nutritional factors in plant protein sources for fish meal replacement in fish feeds, cottonseed and soybean meal (CS) were fermented with Aspergillus oryzae. A feeding trial was conducted to verify the effects of fermented CS (FCS) with phytase supplementation on gossypol detoxification, phosphorus digestibility, antioxidant activity, and growth performance of juvenile olive flounder over 10 weeks. Four diets were formulated to replace 0, 30, or 40% fish meal protein with CS or FCS (designated as CS0, CS30, FCS30P, and FCS40P). Phytase (1,000 FTU/kg) was added to FCS30P and FCS40P. The microbial fermentation significantly increased dietary total polyphenols and consequently led to higher DPPH radical-scavenging activities in fish feed and fish tissue. Dietary and liver gossypol concentrations were dramatically decreased by the fermentation process. Phosphorus digestibility was significantly increased in fish fed the FCS40P diet. However, growth performance decreased in fish fed FCS diets. This study demonstrates that the fermentation process and phytase supplementation can improve the phosphorus availability of plant protein sources in fish. The fermentation of CS by A. oryzae could increase antioxidant activities in feed and fish and effectively degrade toxic gossypol in cottonseed meal.