• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.127-127
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• 2003

Haptophyta(이하 하프토조로 표기)는 그 일부종이 toxin을 가지며, 더욱이 이들 종들이 원인 생물로 발생하는 bloom으로 인한 경제적 피해 발생 등으로 인해 최근 여러 나라에서 활발한 연구가 이루어지고 있다. 남해안 일대의 몇몇 어ㆍ패류 양식장에서 이용하고 있는 식물먹이생물 및 동물먹이생물의 배양수조 내에서 배양을 목적으로 하는 먹이생물 이외의 혼재 생물의 종류를 조사하던 중 Haptophyta의 Prymnesium속 생물이 혼재하고 있는 것을 발견하였으며, 혼재된 Prymnesium은 양식 패류의 인공 종묘 생산 과정에서 사육 치패의 먹이로 이용되는 식물먹이생물 Isochrysis galbana의 증식을 크게 억제하였고, 더욱이 Prymnesium이 혼재된 Isochrysis galbana를 인공 종묘생산 중이던 치패에 투이한 결과 치패 모두가 폐사에 이르는 것을 관찰하였다. 이에 Isochrysis galbana의 배양 수조내에 Prymnesium이 혼입 하였을 경우 Isochrysis galbana의 증식양상을 알아보기 위해, Isochrysis galbana의 세포밀도를 5,440,000cells/ml로 하고 Prymnesium의 세포밀도를 10,000cells/ml로 하여 혼합 배양한 결과 배양개시 1일 후의 각 세포밀도는 Isochrysis galbana가 1,040,000cells/ml로 급격히 저하하였으며, 이와는 달리 Prymnesium은 50,000cells/ml로 증가하였다. 이들 종 각각의 증가 및 감소추세는 계속되어 배양개시 5일 후에는 Isochrysis galbana가 530,000cells/ml로 처음 배양당시 세포수의 90% 이상 감소하였고, Prymnesium은 43,333cells/ml로 4배 이상 증가하였다. 이 실험에서 Isochrysis galana의 세포수가 감소하는 이유는 정확히 알 수는 없으나, 하프토조의 일부 종에서는 광합성을 통한 유기물합성 이외에도 외부로부터의 DOC(dissolved organic carbon)를 직접 배양수로부터 취하거나 또는 영양염 제한 조건에서는 food particle을 섭취하는 경우가 있는 것으로 보고되고 있다. 한편, 이들 Haptopyta가 양식장에서 이용되어지는 해수를 통해 유입되는지를 알아보기 위해 모래여과조를 통과한 해수를 플랑크톤 배양용 배지의 첨가 없이 배양한 결과, Haptophyta의 Prymnesium, Chrysochromulina 및 Phaeocystis 둥의 수 종이 출현하였으며, 일부 종의 경우는 일정기간 지속적으로 배양되어짐을 알 수 있었다.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.4
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• pp.343-350
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• 2012

Even though the microalgal species of Isochrysis and Pavlova are widely used as live food in bivalve hatcheries, they are difficult to culture in mass during the summer season. Therefore, the present study was conducted to determine the optimum species or strains of Isochrysis and Pavlova to produce good growth and high contents of fatty acids at temperatures over $30^{\circ}C$. Four species of Isochrysis (I. galbana KMMCC12, I. galbana KMMCC214, I. aff. galbana, and Isochrysis sp.) and four of Pavlova (P. lutheri, P. gyrans, P. viridis, and Pavlova sp.) were cultured at $25^{\circ}C$, $29^{\circ}C$, and $33^{\circ}C$, and then analyzed for specific growth rate and fatty acid composition. Microalgae were cultured in f/2 medium at 23 psu and continuous light of $80{\mu}mol$ photons $m^{-2}s^{-1}$. For the I. galbana, growth rates were highest at $29^{\circ}C$ and decreased at $33^{\circ}C$ to the level observed at $25^{\circ}C$. I. galbana (KMMCC12) and Isochrysis sp. cultured at $29^{\circ}C$ and $33^{\circ}C$, respectively, exhibited the highest growth rates of all Isochrysis species. In terms of fatty acids, I. galbana (KMMCC12) contained higher contents of PUFA and n-3 HUFA at $33^{\circ}C$ than did Isochrysis sp. For species of Pavlova, growth rates of P. gyrans and P. viridis at $29^{\circ}C$ and $33^{\circ}C$, respectively, were higher than those of the other Pavlova species. In particular, P. viridis grew as well at $33^{\circ}C$ as it did at $29^{\circ}C$. However, P. lutheri and Pavlova sp. did not grow at $33^{\circ}C$. In terms of fatty acids, P. viridis cultured at $33^{\circ}C$ also exhibited higher contents of PUFA and n-3 HUFA, as compared to P. gyrans. Based on these results, we suggest that I. galbana (KMMCC12) and P. viridis are suitable species for mass culture during the high temperature season.

• Journal of the Korean GEO-environmental Society
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• v.13 no.10
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• pp.63-68
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• 2012

This study was performed to determine optimum conditions of batch type cultivation of Isochrysis galbana cultivated under various wavelengths of light emitting dioes (LEDs). Among LEDs used in the cultivation, white LED was found to be the most effective light source, and light intensity of 3,000Lux resulted in the most effective for the cultivation of Isochyrysis galbana. Comparison with common light source, fluorescent light, showed less effective than that with white LED. Four different air flow rates were tested to overcome shading effects due to denser cell concentration in the solution. In results, cell growth rates and maximum cell concentrations were similar regardless of air flow rates. Three times greater cell concentrations, however, were observed when air was applied.

• The Korean Journal of Malacology
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• v.26 no.4
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• pp.303-310
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• 2010

Rearing condition and species of microalgae on growth and survival of the sunray surf clam, Mactra chinensis larvae were investigated for artificial seedling production. The larvae of M. chinensis on higher temperature showed high growth and low survival and was grown over $230{\mu}m$ in shell length 14 days after hatching, but low growth as $151.1{\mu}m$ at $18^{\circ}C$. The larvae of M. chinensis on salinity showed highest daily growth and survival as $11.3{\mu}m$ and 65.8% at 30 psu, respectively. The optimum of water temperature and salinity for the larval rearing were $23^{\circ}C$ and 30-35 psu over 25 psu at least. The density of larval rearing was below 10 per 1 ml in rearing seawater for elevating the development rate from D-shaped to settled (metamorphosing) stage. The larvae fed the mixed diet of Isochrysis galbana, Pavlova lutheri, Isochrysis sp. (green), Chlorella ellipsoidea showed highest growth and survival. The larvae fed the single diet of I. galbana, Isochrysis sp. (green) showed high growth and survival. But the larvae fed the single diet of P. lutheri and C. ellipsoidea showed low growth and survival. The optimum diet of larvae of M. chinensis was over two species of microalgae included I. galbana, Isochrysis sp. (green) for elevating the high growth and survival.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2005.09a
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• pp.136-147
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• 2005

The inhibitor, a kind of ethyl acetate crude extract, was isolated from the old culture liquid of I.galbana. Through measured the culture density, the contents of chlorophyll a. polysaccharide and protein in the cells, the inhibitory effect of the inhibitor on the growth of cells was investigated. The results showed that the inhibitor obviously inhibited the cell growth of three microalgae.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.287-288
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• 2001

해양미세조류인 Isochrysis galbana는 그들의 우수한 영양적인 특성, 특히, 필수영양소 중 고도불포화지방산의 함량이 높아 어류뿐만 아니라 패류, 갑각류의 유생사육 시먹이로서 널리 사용되고 있다. 그러나 이들의 먹이로써 공급하기 위한 기존의 먹이생물 배양기술은 획일적 인 배지의 선택, 단순한 환경조건 (pH, 온도, 빛의 세기, 기체공급속도)등으로 인해 낮은 세포농도 밖에 키울 수가 없다. 이는 먹이확보를 위해 배양 공간을 그 만큼 넓게 차지하게 되며, 이로 인한노동력의 증가와 시설비의 증가는 결국 생산비의 증가를 초래한다. (중략)

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.4
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• pp.475-483
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• 2015

The marine microalgae Isochrysis galbana was cultured under various light-emitting diode (LED) light conditions with different wavelengths to examine changes in growth and in amino acid and fatty acid profiles. The culture conditions for the microalgae were Conway medium, salinity of 33 psu, temperature of $24^{\circ}C$, and a 16/8 h light/dark photoperiod. Six light sources, including 5 units of 180W LED lamps (peak wavelength: blue [LB] 470 nm; green [LG] 525 nm; yellow [LY] 595 nm; red [LR] 636 nm; white [LW] 442 nm) and 1 unit of a 175W metal halide (MH) lamp, were used for the experiment. The dry cell weights ($gL^{-1}$) of I. galbana under different light conditions were in the order of LW>LB${\geq}$MH>LR>LG>LY. Levels of essential amino acids were revealed to be significantly higher under LW, LG, and MH than under the other wavelengths (P<0.05). The fatty acid, unsaturated fatty acid, and DHA contents of I. galbana were higher under MH, LW, and LG. In addition, the carotenoid content was higher under MH, LW, and LG than under the other wavelengths (P<0.05). The fucoxanthin content was highest under MH (0.28%) and lowest under LY (0.2%), and it was 0.26% under LW and LG. The results indicate that the combined use of LW and LG is effective when using LED lamps for I. galbana cultivation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.567-573
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• 1998

Cold storage of concentrated food phytoplanktons is a useful technique in supplying food organisms for artificial shellfish seed. One month after preservation at $4^{\circ}C$, we have measured survival rate of the concentrated food phytoplanktons, Pavlova lutheli, Isochrysis galbana, Isochrysis aff, galbana and Chaetoceros calcitrans. Thereafter we determined survival rate of oyster lavae fed fresh and concentrated diets and fatty acid compositions of the fresh and concentrated food phytoplanktons. Survival rate of concentrated planktons ranged from $23\%$ to $31\%$ after one month at $4^{\circ}C$. The survival rate of oyster larvae fed cold stored food appeared generally higher than those fed fresh harvested food. Especially, the highest survival rate were found in the larvae fed cold stored concentrated I. aff. galbana. EPA and DHA increased after cold storage and the highest level of DHA was detected in I. aff. galbana. As DHA can role as an important factor in determing nutritional value, it would be better to use concentrated I aff, gaibana kept in cold refrigerator for oyster seed production.

• The Korean Journal of Malacology
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• v.23 no.1
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• pp.51-57
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• 2007

This study examined the possibility on the dietary value and cryopreservation of the marine microalga, Isochrysis galbana. Four cryoprotectants, dimethyl sulfoxide (DMSO), ethylene glycol (EG), glycerol (Gly) and 1.2-propanedial (PD) were tested at the concentrations of 1.0, 1.5, 2.0, 2.5 and 3.0 M respectively. The highest survival rates were obtained with 1.5 and 2.0 M of four cryoprotectants yielding a survival rate of 80%. Cell concentration of $30\;{\times}\;10^4\;cell/ml$ at the initial point of the experiment was increased to $365\;{\times}\;10^4\;cell/ml$ in 1.5 M of dimethyl sulfoxide, $298\;{\times}\;10^4\;cell/ml$ in 1.5 M of ethylene glycol, $512\;{\times}\;10^4\;cell/ml$ in 1.5 M of glycerol, and $385\;{\times}\;10^4\;cell/ml$ in 1.5 M of 1.2-propanedial after five days, respectively. In dietary value experiment, survival rate and growth were not significantly different.

• Journal of Aquaculture
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• v.18 no.2
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• pp.86-91
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• 2005

Three haptophyte algae, Isochrysis galbana, Prymnesium parvum and P. patelliferum were offered to the marine copepod Tigriopus japonicus as food. Growth rate of larvae, egg production, mortality and comsumption rates of T. japonicus were measured for each of the haptophyte species offered. The growth rate of larvae, egg production and algal ingestion of T. japonicus fed on P. parvum and P. patelliferum were much lower than those fed on I. galbana and corresponding high mortality rates were also observed during the experimental period. The harmful effects observed during the present study indicate that bloom-forming haptophyte algae, P. parvum and P. patelliferum are not suitable feed species for culture of copepod, T. japonicus.