• Membrane and Water Treatment
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• 제10권3호
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• pp.191-199
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• 2019

In this study, we investigated the cultivation possibility using Hydrodictyon reticulatum in a continuous raceway pond as a tertiary sewage treatment plant. The cultivation possibility was evaluated by varying the light quantity, wavelength, and hydraulic retention time (HRT). Experimental results showed that the growth rates of algae and the removal efficiencies of nutrients increased as the light quantity increased, and the maximum photosynthetic rate was maintained at $100{\mu}mol/m^2{\cdot}s$ or higher. When wavelength was varied, nutrient removal efficiency and growth rate increased in the following order: green light, red light, white light, and blue light. The nutrient removal efficiencies and algae productivity in HRT 4 d were better than in HRT 8 d. We conclude that if Hydrodictyon reticulatum is cultivated in a raceway pond and used as a tertiary treatment facility in a sewage treatment plant, nutrients can be effectively removed, and production costs can be reduced.

• Journal of Microbiology and Biotechnology
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• 제32권3호
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• pp.378-386
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• 2022

Scenedesmus obliquus ABC-009 is a microalgal strain that accumulates large amounts of lutein, particularly when subjected to growth-limiting conditions. Here, the performance of this strain was evaluated for the simultaneous production of lutein and biofuels under three different modes of cultivation - photoautotrophic mode using BG-11 medium with air or 2% CO₂ and heterotrophic mode using YM medium. While it was found that the highest fatty acid methyl ester (FAME) level and lutein content per biomass (%) were achieved in BG-11 medium with CO₂ and air, respectively, heterotrophic cultivation resulted in much higher biomass productivity. While the cell concentrations of the cultures grown under BG-11 and CO₂ were largely similar to those grown in YM medium, the disparity in the biomass yield was largely attributed to the larger cell volume in heterotrophically cultivated cells. Post-cultivation light treatment was found to further enhance the biomass productivity in all three cases and lutein content in heterotrophic conditions. Consequently, the maximum biomass (757.14 ± 20.20 mg/l/d), FAME (92.78 ± 0.08 mg/l/d), and lutein (1.006 ± 0.23 mg/l/d) productivities were obtained under heterotrophic cultivation. Next, large-scale lutein production using microalgae was demonstrated using a 1-ton open raceway pond cultivation system and a low-cost fertilizer (Eco-Sol). The overall biomass yields were similar in both media, while slightly higher lutein content was obtained using the fertilizer owing to the higher nitrogen content.

• 환경생물
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• 제32권1호
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• pp.26-34
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• 2014

에너지 소비의 증가와 화석 연료의 감소로 인해 바이오디젤과 같은 재생 가능한 대체 에너지 자원이 관심을 받고 있다. 미세조류를 이용한 바이오디젤은 기존의 농작물과 경쟁하지 않는 것과 더불어 많은 장점을 갖고 있다. 본 연구에서는 미세조류 배양의 생산 비용 절감과 축산 폐수 처리라는 두 가지 목표를 충족시키지 위해 돈분 액체 비료를 사용하였다. 옥외 배양 시스템(Small Scale Raceway Pond; SSRP)과 희석된 돈분 액체 비료를 이용하여 단일 미세조류 Chlorella sp. JK2, Scenedesmus sp. JK10 과 혼합 토착 미세조류 CSS를 20일 동안 각각 배양하였다. 미세조류 혼합균주인 CSS의 바이오매스 생산과 지질 생산성은 각각 $1.19{\pm}0.09gL^{-1}$, $12.44{\pm}0.38mgL^{-1}day^{-1}$로 단일 종에 비해 2배 이상 높았다. 돈분 액체 비료의 TN, TP의 제거율 역시 혼합 토착 미세조류 CSS에서 93.6%, 98.5%로 단일 종의 이용에 비해 30%이상 높은 제거 효율을 보여주었다. 이를 통해 돈분 액체 비료는 미세조류 배양에 필요한 N과 P를 제공하며, 미세조류를 이용한 SSRP를 통하여 영양염류를 제거할 수 있는 가능성을 확인하였다. 또한 미세조류 배양을 위한 생산 비용의 감소로 경제성 있는 바이오디젤의 생산 가능성을 확인하였다.

• 미생물학회지
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• 제50권4호
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• pp.313-318
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• 2014

최근 지구온난화문제와 화석연료 자원의 부족문제로 인해 지속적이고 친환경적인 미세조류 기반 바이오디젤이 주목받고 있다. 본 연구에서는 돈분 액체비료와 농업용 복합비료가 바이오 디젤 생산을 위한 미세조류 영양원으로 활용될 가능성을 확인해 보았다. 혼합 미세조류 CSS (Chlorella spp., Scenedesmus spp., Stigeoclonium spp.) 배양을 위한 영양원은 돈분 액체비료, 돈분 액체비료와 농업용 복합비료의 혼합, 농업용 복합비료이며, 28일간 Small Scale Raceway Pond (SSRP)에서 옥외배양하였다. 그 결과 혼합 실험구의 바이오매스와 지질 생산성은 각각 0.8g/L, 5.8 mg/L/day로 가장 우수한 바이오매스량과 지질 생산성을 보여주었다. 이 연구를 통해 농업용 복합비료와 돈분 액체비료의 혼합액이 미세조류에 안정적인 영양 공급을 하는 영양원으로 활용될 가능성을 확인하였다. 또한, 미세조류 배양단가와 바이오디젤 생산단가를 낮출 가능성도 탐구하였다.

• Journal of Microbiology and Biotechnology
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• 제24권11호
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• pp.1566-1573
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• 2014

Although most algae cultivation systems are operated in suspended culture, an attached growth system can offer several advantages over suspended systems. Algal cultivation becomes light-limited as the microalgal concentration increases in the suspended system; on the other hand, sunlight penetrates deeper and stronger in attached systems owing to the more transparent water. Such higher availability of sunlight makes it possible to operate a raceway pond deeper than usual, resulting in a higher areal productivity. The attached system achieved 2.8-times higher biomass productivity and total lipid productivity of $9.1g\;m^{-2}day^{-1}$ and $1.9g\;m^{-2}day^{-1}$, respectively, than the suspended system. Biomass productivity can be further increased by optimization of the culture conditions. Moreover, algal biomass harvesting and dewatering were made simpler and cheaper in attached systems, because mesh-type substrates with attached microalgae were easily removed from the culture and the remaining treated wastewater could be discharged directly. When the algal biomass was dewatered using natural sunlight, the palmitic acid (C16:0) content increased by 16% compared with the freeze-drying method. There was no great difference in other fatty acid composition. Therefore, the attached system for algal cultivation is a promising cultivation system for mass biodiesel production.