• 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.

• ALGAE
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• 제39권1호
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• pp.17-30
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• 2024

Red macroalga Pyropia yezoensis is a high valuable cultivated marine crop. Its acclimation to cold stress is especially important for long cultivation period across winter in coasts of warm temperate zone in East Asia. In this study, the response of P. yezoensis thalli to low temperature was analyzed on physiology and transcriptome level, to explore its acclimation mechanism to cold stress. The results showed that the practical photosynthesis activity (indicated by Φ_PSII and qP) was depressed and pigment allophycocyanin content was decreased during the cold stress of 48 h. However, the F_v/F_m and non-photochemical quenching increased significantly after 24 h, and the average growth rate of thalli also rebounded from 24 to 48 h, indicating a certain extent of acclimation to cold stress. On transcriptionally, the low temperature promoted the expression of differentially expressed genes (DEGs) related to carbohydrate metabolism and energy metabolism, while genes related to photosynthetic system were depressed. The increased expression of DEGs involved in ribosomal biogenesis and lipid metabolism which could accelerate protein synthesis and enhance the degree of fatty acid unsaturation, might help P. yezoensis thallus cells to cope with cold stress. Further co-expression network analysis revealed differential expression trends along with stress time, and corresponding hub genes play important roles in the systemic acquired acclimation to cold stress. This study provides basic mechanisms of P. yezoensis acclimation to cold temperature and may aid in exploration of functional genes for genetic breeding of economic macroalgae.

• 한국양식학회지
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• 제5권1호
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• pp.81-91
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• 1992

해산동물의 종묘생산시 초기단계의 먹이로써 미세조류의 배양은 매우 중요하다. 그러나 자연으로부터 먹이생물로써 필요한 미세조류를 순수분리하여 순종을 보관하는 일은 일반 양식 업자나 이 분야에 종사하지 않는 연구자에게는 매우 어려운 일이다. 따라서 미세조류를 필요로 하는 사람들에게 순종의 미세조류 strain을 공급할 수 있는 은행의 설립이 필요하다. 본 연구에서는 capilla교 pipette법, 한천도말법, 희석법을 이용하여 한국연안에서 80종의 미세조류를 분리하였다. 현재 부산수산대학교 양식학과 실험실에서 확보 배양중인 117종의 미세조류의 배양현황을 보고하였다.

• ALGAE
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• 제17권3호
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• pp.187-194
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• 2002

A seaweed biofilter/production system of being developed to reduce the environmental impact of marine fish farm effluent in coastal ecosystems as a part of an integrated aquaculture system. Several known seaweed taxa and their cultivars have been considered as candidate biofilter organisms based on their species-specific physiological properties such as nutrient uptake kinetics and their economic value. Porphyra is an excellent cadidate and shows efficient nutrient extraction properties. Rates of ammonium uptake were maintained at around 3 ${\mu}moles{\cdot}g{\cdot}dw^{-1}{\cdot}min^{-1}$ at 150 ${\mu}M$ inorganic nitrogen at $10^{\circ}C$. Ulva is another possible biofilter candidate with an uptake rate of 1.9 ${\mu}moles{\cdot}g{\cdot}dw^{-1}{\cdot}min^{-1}$ under same conditions. A simple uptake/growth and harvest model was applied to estimate the efficiency of the biofilter/production system. The model was deterministic and used a compartment model structure based on difference equations. The efficiency of Porpyra filter was estimated over 17% of ${NH_4}^+$ removal from the contimuous supply of 100 ${\mu}mole{\cdot}l^{-1}\;{NH_4}^+\;at\;100l{\cdot}sec^{-1}$ flow rate.

• Biotechnology and Bioprocess Engineering:BBE
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• 제5권3호
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• pp.181-185
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• 2000

A marine microorganism, strain 96CJ10356 produced exopolysaccharide, designated as EPS-R. To optimize culmize culture conditions for the production of EPS-R, carbon and nitrogen sources, mineral salts, temperature, and pH were exmined. From this study, STN medium for the production of EPS-R was suggested as follows; sucrose 20g, typtone 10g, NaCl 10g, MgSO45g, CaCl21g, KH2PO4 76mg, K2HPO4 83mg, FeCl2 5mg, MnCl2 1mg, NaMoO4 1mg, and ZnCl2 1mg per liter at pH 7.0. About 9.23g/L of EPS-R was obtained from STN medium after cultivation for 120h at $25^{\circ}C$ in a 5-liter jar fermentor with an aearation rate of 0.17 vvm. Apparent viscosity and flocculation activity of the culture broth were increased with the production of EPS-R and the maximal values were 415 cP and 1400 unit/mL against 0.5% activated carbon, respectively.

• Journal of Microbiology and Biotechnology
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• 제8권3호
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• pp.245-250
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• 1998

A gene encoding an extracellular collagenase from the marine bacterium Vibrio vulnificus CYK279H was cloned into E. coli JM83 using the multicopy plasmid vector pUC19. The cloned strain of recombinant E. coli showing collagenase activity had an insert fragment of 3.5 kb and was named E. coli JM83/pKCL 279H. The cloned strain produced two different collagenase during cultivation. These enzymes, named collagenase-I and -II, were purified from the culture supernatant. SDS-PAGE indicated that collagenase-I had a molecular weight of 41 kDa and collagenase-II had a weight of 37 kDa. The N-terminal amino acid sequence of collagenase-I from the cloned strain, E. coli JM83/pKCL279H was determined and was not found to be similar to any other known collagenases. The optimum pH and temperature of the purified collagenase-I were 7.8 and $37^{\circ}C$, respectively.

• 수산경영론집
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• 제45권2호
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• pp.1-13
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• 2014

This study analyzes patent trends regarding farming-related technologies such as breeding or nursery technology, production systems, and new cultivation methods in order to provide objective patent information about the trends of R&D on marine products' proliferation or farming. Presently, in Korea, we try to secure marine living resources through the formation of artificial resources instead of environmental improvement policy or resource management policy. However, this is not about eliminating the causes of marine environment destruction but just the policy for improvement, so it is needed to revise the related policy with more ultimate measures. And it is necessary to develop technology that can secure the rights by integrating patent application strategies from the stage of R&D for medicine that can be utilized in chief farming countries and provide intensive support for the research centering around strategic varieties for farming in each region as well as strategic national farming varieties afterwards. Also, the analysis shows that it is urgent to make applications overseas based on domestic applications in order to develop technology that can be commercialized in not just Korean but overseas market as well.

• 한국해양환경ㆍ에너지학회지
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• 제9권3호
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• pp.168-175
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• 2006

연안 김 양식장의 효과적 관리를 위해서는 실제 시설량의 조사가 필요하며, 인공위성을 이용한 방법이 가장 효과적이다. 본 연구에서는 10m의 해상도를 갖고 있는 SPOT-5 다중분광영상을 사용하였으며, 경기도 화성시 제부도 남방 해역에 김 양식장의 자동탐지 기법을 적용하고 평가하였다. 김 양식장을 추출하기 위하여 우선 3밴드 영상의 분광 특성을 이용한 밴드차(Band difference) 영상을 작성하여, 두 가지 방법(형태학적 처리기법 및 Canny 에지 탐지기법)으로 처리를 한 후, 두 결과를 합성하여 레이블링함으로써 탐지율을 극대화하였다. 인공위성영상을 이용하여 얻어진 2005년 한국연안 김 양식장 시설량은 676,749책(柵)으로, 면허시설량 572,745책보다 많은 것으로 나타났다. 또한, 준법시설 비율은 52.9%로 아주 낮았다. 이와 같은 양식장 시설 현황 조사 결과는, 정부에서 전체 생산량을 조절할 수 있게 하여 안정적인 시장 가격을 유지하는데 도움이 될 수 있을 것이다.

• 한국해양바이오학회지
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• 제8권1호
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• pp.39-44
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• 2016

The microalgae have been studied for a source of biodiesel production. It is important to select the microalgae, which grows rapidly in local environmental conditions such as temperature range and ingredient of local seawater. The aim of this study was isolating microalga, which has rapid growth rate and high FAME contents in wide temperature ranges, for microalgal offshore cultivation in Korea, one of the country with four distinct seasons. Firstly, we had isolated a green microalga, Tetraselmis sp. KCTC12236BP, which has faster growth rate in low temperature (5 and $10^{\circ}C$) than Tetraselmis suecica and Dunaliella tertiolecta LB999 from Young Heung Island, Incheon, Korea. This microalga was cultivated in outdoor circulated tank photobioreactor (CT-PBR). As a result, this microalga could grow in wide temperature ranges (6 to $29^{\circ}C$), outdoors. After that, the biomass was recovered, and 13.2 g biodiesel could be acquired from 110 g dry biomass. These results indicate that the isolated microalga, Tetraselmis sp. KCTC12236BP is proper to biodiesel production using outdoor cultivation in Korea for all seasons.

• ALGAE
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• 제39권2호
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• pp.109-127
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• 2024

High production and efficient harvesting of microalgae containing high omega-3 levels are critical concerns for industrial use. Aeration can elevate production of some microalgae by providing CO₂ and O₂. However, it may lower the production of others by generating shear stress, causing severe cell damage. The mixotrophic dinoflagellate Gymnodinium smaydae is a new, promising microalga for omega-3 fatty acid production owing to its high docosahexaenoic acid content, and determining optimal conditions and methods for high omega-3 fatty acid production and efficient harvest using G. smaydae is crucial for its commercial utilization. Therefore, to determine whether continuous aeration is required, we measured densities of G. smaydae and the dinoflagellate prey Heterocapsa rotundata in a 100-L semi-continuous cultivation system under no aeration and continuous aeration conditions daily for 9 days. Furthermore, to determine the optimal conditions for harvesting through centrifugation, different rotational speeds of the continuous centrifuge and different flow rates of the pump injecting G. smaydae + H. rotundata cells into the centrifuge were tested. Under continuous aeration, G. smaydae production gradually decreased; however, without aeration, the production remained stable. Harvesting efficiency and the dry weights of omega-3 fatty acids of G. smaydae + H. rotundata cells at a rotational speed of 16,000 rpm were significantly higher than those at 2,000-8,000 rpm. However, these parameters did not significantly differ at injection pump flow rates of 1.0-4.0 L min^-1. The results of the present study provide a basis for optimized production and harvest conditions for G. smaydae and other microalgae.