• Journal of Microbiology and Biotechnology
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• 제25권9호
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• pp.1547-1554
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• 2015

The potential of microalgae biofuel has not been realized because of the low productivity and high costs associated with the current cultivation systems. In this study, a new low-cost and transparent attachment material was tested for cultivation of a filamentous algal strain, Stigeoclonium sp., isolated from wastewater. Initially, the different materials tested for Stigeoclonium cultivation in untreated wastewater were nylon mesh, polyethylene mesh, polypropylene bundle (PB), polycarbonate plate, and viscose rayon. Among the materials tested, PB led to a firm attachment, high biomass (53.22 g/m², dry cell weight), and total lipid yield (5.8 g/m²) with no perceivable change in FAME profile. The Stigeoclonium-dominated biofilm consisted of bacteria and extracellular polysaccharide, which helped in biofilm formation and for effective wastewater treatment (viz., removal efficiency of total nitrogen and total phosphorus corresponded to ~38% and ~90%, respectively). PB also demonstrated high yields under multilayered cultivation in a single reactor treating wastewater. Hence, this system has several advantages over traditional suspended and attached systems, with possibility of increasing areal productivity three times using Stigeoclonium sp. Therefore, multilayered attached growth algal cultivation systems seem to be the future cultivation model for large-scale biodiesel production and wastewater treatment.

• 생태와환경
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• 제45권1호
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• pp.21-33
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• 2012

동강 수계의 식물플랑크톤 군집 구조를 알아보기 위하여 2008년 5월부터 2009년 4월까지 22개 지점에서 총 4 회 조사를 실시하였다. 동강수계에서 출현한 식물플랑크톤은 총 159종으로서 7강 58속 113종 21변종 25미동정종으로 구성되어 있으며, 규조강이 90종류로 전체 중 56.6%로 가장 높은 점유율을 나타냈고, 그 다음으로 녹조강이 47종류로 29.6%의 점유율을 나타냈으며 남조강이 17종으로 10.7%, 유글레나강이 2종으로 1.3%, 황색편모조강, 갈색편모조강, 와편모조강이 각각 1종 0.6% 순으로 나타났다. 조사기간 모든 시기 20정점 이상에서 출현한 보편종은 Cocconeis placentula, Cymbella minuta, Diatoma vulgare, Melosira varians, Navicula cryptocephala, Scenedesmus acuminatus v. acuminatus 등 6종이었다. 현존량은 86 cells $mL^{-1}$~1,467 cells $mL^{-1}$의 범위로 나타났고, 점유율이 10% 이상인 우점종은 Achnanthes minutissima, Asterionella formosa, Aulacoseira ambigua, Cocconeis placentula, Coelastrum microporum, Cyclotella sp., Cymbella affinis, C. minuta, C. tumida, Diatoma vulgare, Fragilaria capucina, F. construens, F. crotonensis, Gomphonema affine, G. clevei, Melosira varians, Merismopedia elegans, Navicula cryptocephala N. pupula, Nitzschia tryblionella, Oscillatoria anna, O. limosa O. tenuis v. tenuis, Pediastrum duplex v. reticulatum, Phormidium tenue, Scenedesmus acuminatus v. acuminatus, S. acutus v. acutus, S. ecornis v. ecornis, S. quadricauda v. quadricauda, Spirogyra sp., Stigeoclonium sp., Synedra acus, S. ulna, Ulothrix sp. 등 34종이었는데, 가장 중요한 종은 90개 시료 중 52개에서 우점종으로 나타난 Cymbella minuta이었다 종다양성지수는 1.58~3.10, 균등도지수는 0.51~0.95, 우점도지수는 0.22~0.74의 범위로 연구지역이 상당히 안정된 것으로 조사되었다. 본 조사지역의 상류정점의 식물플랑크톤 군집구조는 도암호에서 나오는 방류수에 의해 영향을 받는 것으로 사료된다.

• Journal of Microbiology and Biotechnology
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• 제28권4호
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• pp.630-637
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• 2018

The high rate algal ponds (HRAP) powered and mixed by a paddlewheel have been widely used for over 50 years to culture microalgae for the production of various products. Since light incidence is limited to the surface, water depth can affect microalgal growth in HRAP. To investigate the effect of water depth on microalgal growth, a mixed microalgal culture constituting three major strains of microalgae including Chlorella sp., Scenedesmus sp., and Stigeoclonium sp. (CSS), was grown at different water depths (20, 30, and 40 cm) in the HRAP, respectively. The HRAP with 20cm of water depth had about 38% higher biomass productivity per unit area ($6.16{\pm}0.33g{\cdot}m^{-2}{\cdot}d^{-1}$) and required lower nutrients and energy consumption than the other water depths. Specifically, the algal biomass of HRAP under 20cm of water depth had higher settleability through larger floc size (83.6% settleability within 5 min). These results indicate that water depth can affect the harvesting process as well as cultivation of microalgae. Therefore, we conclude that water depth is an important parameter in HRAP design for mass cultivation of microalgae.

• Journal of Microbiology and Biotechnology
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• 제24권8호
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• pp.1123-1132
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• 2014

This study evaluated the growth and nutrient removal ability of an indigenous algal consortium on real untreated municipal wastewater in a high rate algal pond (HRAP). The HRAP was operated semicontinuously under different hydraulic retention times (HRT: 2, 4, 6, and 8 days). The average removal efficiencies of chemical oxygen demand, and total nitrogen and phosphate of real municipal wastewater were maintained at $85.44{\pm}5.10%$, $92.74{\pm}5.82%$, and $82.85{\pm}8.63%$, respectively, in 2 day HRT. Algae dominated the consortium and showed high settling efficiency (99%), and biomass and lipid productivity of $0.50{\pm}0.03g/l/day$ and $0.103{\pm}0.0083g/l/day$ (2day HRT), respectively. Fatty acid methyl ester analysis revealed a predominance of palmitate (C16:0), palmitoleate (C16:1), linoleate (C18:2), and linolenate (C18:3). Microalgal diversity analyses determined the presence of Chlorella, Scenedesmus, and Stigeoclonium as the dominant microalgae. The algal consortium provides significant value not only in terms of energy savings and nutrient removal but also because of its bioenergy potential as indicated by the lipid content (20-23%) and FAME profiling.