• Journal of Microbiology and Biotechnology
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• 제26권7호
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• pp.1285-1289
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• 2016

A split-column photobioreactor (SC-PBR), consisting of two bubble columns with different sizes, was developed to enhance the photon utilization efficiency in an astaxanthin production process from Haematococcus lacustris. Among the two columns, only the smaller column of SC-PBR was illuminated. Astaxanthin productivities and photon efficiencies of the SC-PBRs were compared with a standard bubble-column PBR (BC-PBR). Astaxanthin productivity of SC-PBR was improved by 28%, and the photon utilization efficiencies were 28-366% higher than the original BC-PBR. The results clearly show that the effective light regime of SC-PBR could enhance the production of astaxanthin.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권2호
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• pp.103-108
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• 2005

For more accurately describing the durations of the light and the dark phases of micro-algal cells over the whole light-dark cycle, and probing into the relationship between the liquid circulation time or velocity, the aeration rate and cell density, a series of experiments was carried out in 10 cm light-path flat plate photobioreactors. The results indicated that the liquid flow in the flat plate photobioreactor could be described by liquid dynamic equations, and a high biomass output, higher content and productivity of arachidonic acid, $70.10\;gm^{-2}d^{-1},\;9.62\%$ and 510.3 mg/L, respectively, were obtained under the optimal culture conditions.

• 한국해양바이오학회지
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• 제8권1호
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• pp.18-23
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• 2016

It is important to design photobioreactor by cheap material for economical microalgal biomass production. In this study, two types of marine photobioreactors (MPBR), made by either polyvinyl chloride (MPBR-PVC) or high density poly ethylene (MPBR-HDPE), are used and performance of these were compared. Tetraselmis sp. KCTC 12236BP is a green marine alga that isolated from Ganghwa Island, Korea, and the strain was used for marine cultivations using MPBR-PVC and MPBR-HDPE. The cultivations were performed three times in the spring season of 2012 using MPBR-PVC and of 2013 using MPBR-HDPE in the coastal area of Young Heung Island. As the results, MPBR-PVC shows higher biomass productivities than MPBR-HDPE, due to its high light transmittance. In the cultivations using MPBR-PVC, the average sea water temperature was $11.5^{\circ}C$ during the first experiment and $16.5^{\circ}C$ during the second and third experiments. Average light intensities during three times for experiments were 407.5, 268.1 and $273.0{\mu}{\cdot}E{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. The maximum fresh cell weight and average biomass productivity were $1.2g{\cdot}L^{-1}$ and $0.12g{\cdot}L^{-1}{\cdot}day^{-1}$. These results showed that Tetraselmis sp. KCTC12236BP were adapted well with the environmental conditions from ocean, and grow in the MPBR-PVC and MPBR-HDPE.

• Journal of Microbiology and Biotechnology
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• 제31권3호
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• pp.456-463
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• 2021

In this study, the culture conditions for Porphyridium cruentum were optimized to obtain the maximum biomass and lipid productions. The eicosapentaenoic acid content was increased by pH optimization. P. cruentum was cultured with modified F/2 medium in 14-L photobioreactors using a two-phase culture system, in which the green (520 nm) and red (625 nm) light-emitting diodes (LEDs) were used during the first and second phases for biomass production and lipid production, respectively. Various parameters, including aeration rate, light intensity, photoperiod, and pH were optimized. The maximum biomass concentration of 0.91 g dcw/l was obtained with an aeration rate of 0.75 vvm, a light intensity of 300 μmol m-2s-1, and a photoperiod of 24:0 h. The maximum lipid production of 51.8% (w/w) was obtained with a light intensity of 400 μmol m-2s-1 and a photoperiod of 18:6 h. Additionally, the eicosapentaenoic acid and unsaturated fatty acid contents reached 30.6% to 56.2% at pH 6.0.

• 한국해양바이오학회지
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• 제7권2호
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• pp.52-57
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• 2015

The purpose of this study was to investigate a relationship between ultraviolet radiation and initial cell density (ICD) of microalgae using a floating marine photobioreactor (PBR). To examine the effect of ultraviolet (UV) radiation in sunlight on biomass productivity as a function of ICD, 0.5-L floating PBRs covered with or without UV cut-off film were placed in an outdoor rectangular tank containing 200 L of water. At the lower ICDs, 0.01 and 0.05 g/L, biomass productivities in the PBRs without UV cut-off film decreased by $278{\pm}21%$ and $222{\pm}3%$ compared with those with the film, respectively. In contrast, the presence of UV cut-off film did not have a significant effect on biomass productivities at the higher ICDs, 0.25 and 1.25 g/L. When the differences in biomass productivity made by the UV cut-off film were plotted against the sum of cell projection area per light receiving area of the PBR, the results revealed that the inhibitory effect of UV on biomass productivity can be negligible when the sum of cell projection area is equal to the light receiving area of the PBR. These results show that photoinhibition caused by UV radiation could be eliminated via operating the PBR with a proper ICD.

• 한국수산과학회지
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• 제31권1호
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• pp.139-142
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• 1998

미세 조류의 생장에는 적당한 영양염 이외에 온도, pH, 조도 및 $CO_2$ 공급 등을 필요로 한다. 이들 증식 속도에 영향을 미치는 인자를 고려한 대량 배양 시스템을 제작하고자, VT-PBR을 이용하여 국내 해수산 Chlorella sp.의 배양 조건을 검토하였다. 국립수산진흥원 남해수산연구소 충무분소에서 어민에게 공급하고 있는 Chlorella sp.의 배양 최적 조건은 온도 $20^{\circ}C$, 조도 6,0001ux, 공기 공급속도 0.56vvm, 그리고 $CO_2$ 공급속도는 0.028vvm였다.

• 한국수산과학회지
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• 제31권4호
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• pp.477-482
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• 1998

치어의 먹이사료인 동물성 플랑크톤은 단세포조류인 Chlorella를 먹이로 하고 있으며, 우리 나라에서는 현재까지 Chlorella를 연못형 배양조에서 배양하고 있다. 본연구에서는 Chlorella의 생산성을 높이기 위하여 Chlorella 배양 조건 중, 빛의 공급율을 높이는 데에 중점을 두고 여섯 형태의 모형 배양조를 제작하고 Chlorella vulgalis 211-11b의 최대 비증식속도와 생산성을 비교하였다. 모형 배양조 중, ${\mu}_{max}$와 생산성이 가장 큰 것은 HS-Pbr이었으며. 최대 비증식속도와 생산성이 반드시 배양조의 S/V에 비례하지는 않았다.

• Journal of Microbiology and Biotechnology
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• 제26권6호
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• pp.1098-1102
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• 2016

A green microalga, Tetraselmis sp., was cultivated in the coastal seawater of Young-Heung Island using semi-permeable membrane photobioreactors (SPM-PBRs) in different seasons. The microalgae in the SPM-PBRs were able to grow on nutrients diffused into the PBRs from the surrounding seawater through SPMs. The biomass productivity varied depending on the ion permeabilities of the SPMs and environmental conditions, whereas the quality and quantity of fatty acids were constant. The temperature of seawater had a greater influence than solar radiation did on productivity of Tetraselmis sp. in SPM-PBRs. SPM-PBRs could provide technologies for concurrent algal biomass and fatty acids production, and eutrophication reduction in the ocean.

• 한국수산과학회지
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• 제33권5호
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• pp.475-481
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• 2000

미세조류 S. platensis의 성장 및 색소 축적에 대한 배양 조건의 영향을 실험한 결과, 배양 온도 및 빛 강도는 각각 $35^{\circ}C,\;3500 lux$가 가장 적절한 배양 조건이었으며, 온도가 다소 낮은 $30^{\circ}C$ 조건에서는 빛 강도가 3500 lux보다 다소 높은 조건도 고려해볼만 하였다. 빛 강도 및 온도 조건에서의 phycocyanin 색소 함량은 조류의 성장 정도와 직접적인 상관을 나타내었으며, chlorophyll-a 함량과는 특별한 상관성을 가지지 않았다. 배지 중의 $NaHCO_3$ 첨가 농도는 $1.0{\%}$가 조류의 성장 및 색소 축적에 가장 좋은 조건임을 알 수 있었고, 그 이상의 농도에서는 오히려 phycocyanin 색소 생산능이 저하됨을 알 수 있었다. 탄소원인 $Na_2CO_3$는 $0.2{\~}0.3{\%}$ 농도 수준에서 가장 높은 조류의 성장과 phycocyanin을 축적하는 것으로 나타났으며, 첨가 농도가 높아져도 phycocyanin 색소 생산능은 증가되지 않았다. 한편, 질소원으로 첨가되는 $NaCO_3$농도도 $0.2{\~}0.3{\%}$ 범위에서 첨가하는 것이 균체의 성장이나 색소 생산에 바람직한 조건으로 확인되었으며, 과도한 첨가는 성장과 phycocyanin 색소 생산능이 낮아지는 것을 확인할 수 있었다. 전체적으로 chlorophyll-a는 phycocyanin 색소 함량이 증가하면 증가하는 상관을 가졌으나 그 함량은 미미하였다.

• 한국해양바이오학회지
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• 제16권1호
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• pp.36-44
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• 2024

This study attempted to improve the growth of the freshwater microalgae, Parachlorella kessleri, through the sequential optimization of culture conditions. This attempt aimed to enhance the microalgae's ability to fixate atmospheric CO₂. Culture temperature and light intensity appropriate for microalgal growth were scanned using a high-throughput photobioreactor system. The supplied air flow rate varied from 0.05 to 0.3 vvm, and its effect on the growth rate of P. kessleri was determined. Next, sodium phosphate buffer was added to the culture medium (BG11) to enhance CO₂ fixation by increasing the availability of CO₂(HCO₃^-) in the culture medium. The results indicated that optimal culture temperature and light intensity were 20℃-25℃ and 300 μE/m²/s, respectively. Growth rates of P. kessleri under various air flow rates highly depended on the increase of the culture's flow rate and pH which determines CO₂ availability. Adding sodium phosphate buffer to BG11 to maintain a constant neutral pH (7.0) improved microalgal growth compared to control conditions (BG11 without sodium phosphate). These results indicate that the CO₂ fixation rate in the air could be enhanced via the sequential optimization of microalgal culture conditions.