• 한국생산제조학회지
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• 제25권3호
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• pp.237-243
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• 2016

Recently, technologies that produce biofuels from microalgae are being studied worldwide. It is necessary to significantly reduce the production costs of biofuels from microalgae for economic reasons. In this study, the growth curve of the microalgae was obtained using the batch-culture method, and the specific growth rate was predicted using the regression method. Based on the culture conditions of the estimated specific growth rate, the turbidity of the microalgae in the flat panel photobioreactor (PBR) was measured. Furthermore, an on-off control scheme was applied to the flat panel PBR in order to culture the microalgae continuously on the basis of turbidity. The parameters of the on-off control system were displayed by LabView. The on-off scheme of peristaltic pump was controlled based on the turbidity in the PBR. In addition, the turbidity values of growth curves were compared and analyzed in the continuous culture process using the on-off controller.

• 농업과학연구
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• 제47권4호
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• pp.1039-1048
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• 2020

Food waste causes various economic losses and environmental pollution problems such as soil pollution and groundwater pollution. Food waste has been used as a resource in various forms and has been used mostly for feed and composting. This study compared microalgal nutrient medium (BG-11) with food waste compost to determine the possibility of using it as a culture medium. Scenedesmus quadricauda was isolated and cultured in an eutrophic reservoir and incubated for 3 days in distilled water before laboratory use. Food waste compost was produced in two food waste processing facilities, and hot water was extracted in the laboratory to be used for microalgae cultivation. The growth curve of the microalgae was analyzed based on the Chl-a concentration measured during the experiment, and the growth rate of the microalgae grown in the food waste compost was compared with the growth rate of those grown in the nutrient medium. Food waste compost showed a similar growth rate to that of the nutrient medium, and there was a difference depending on the manufacturing facility. The growth of microalgae in such food waste was further amplified when trace elements were added and showed better growth than that of the nutrient media. Particularly, when trace elements were added, the growth rate increased, and the growth period was further extended. Therefore, food waste compost can be sufficiently utilized as a microalgal culture medium, and if trace elements are added, it is considered that microalgae can be more effectively cultured compared to the existing nutrient medium.

• 한국해양환경ㆍ에너지학회지
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• 제12권2호
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• pp.91-95
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• 2009

저서성 미세조류의 성장에 미치는 부착기질의 영향을 알기 위해 서로 다른 크기의 glass bead를 첨가하여 저서성 미세조류 Nitzschia sp.(진해만 클론)의 성장을 조사하였다. 연구에 사용된 glass bead의 크기는 0.09-0.15 mm(G1), 0.25-0.50 mm(G2), 0.75-1.00 mm(G3) 그리고 1.25-1.65 mm(G4)이며, glass bead를 첨가하지 않는 대조구도 설정하였다. Nitzschia sp.의 가장 높은 성장속도(0.37/day)와 최대세포밀도($9,232{\pm}840$ cells/mL)는 가장 작은 크기의 glass bead를 첨가한 G1에서 나타났다. 그리고 성징속도와 최대세포밀도는 glass bead 크기의 증가와 함께 감소하였다(G4의 성장속도와 최대세포밀도는 각각 0.24/day와 $6,397{\pm}524$ cells/mL였다). 더욱이 대조구의 성장속도는 실험구 G1에서 G3의 성장속도보다 상당히 낮았다. 이 결과에서 Nitzschia sp.와 같은 저서성 미세조류를 위한 부착기질은 성장속도 뿐만 아니라 세포밀도에도 큰 영향을 주는 것으로 나타났다. 따라서 부착미세조류의 생리실험을 위해서는 예비실험으로 부착기질의 유무 및 대상 종에 적합한 부착입자의 크기의 고려가 필요할 것으로 보인다.

• Environmental Engineering Research
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• 제24권2호
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• pp.271-278
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• 2019

Mass cultivation of microalgae is necessary to achieve economically feasible production of microalgal biodiesel. However, the high cost of nutrients is a major limitation. In this study, corncob extract (CCE) was used as an inorganic and organic nutrient source for the mass cultivation of Chlorella vulgaris (C. vulgaris). Chemical composition analysis of CCE revealed that it contained sufficient nutrients for mixotrophic cultivation of C. vulgaris. The highest specific grow rate of C. vulgaris was obtained at pH of 7-8, temperature of $25-30^{\circ}C$, and CCE amount of 5 g/L. In the analysis using various growth models, Luong model was found to be the most suitable empirical formula for mass cultivation of C. vulgaris using CCE. Analysis of biomass and production of triacyglycerol showed that microalgae grown in CCE medium produced more than 17.23% and 3% more unsaturated fatty acids than cells cultured in Jaworski's Medium. These results suggest that growing microalgae in CCE-supplemented medium can increase lipid production. Therefore, CCE, agricultural byproduct, has potential use for mass cultivation of microalgae.

• 상하수도학회지
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• 제31권4호
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• pp.357-362
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• 2017

Acetate, propionate, butyrate are the major soluble volatile fatty acids metabolites of fermented food waste leachates. This work investigate the effects of volatile fatty acid on the growth rate and $NH_4-N$, $PO_4-P$ removal efficiency of mixotrophic microalgae Chlorella vulgaris to treat digested food waste leachates. The results showed that acetate, propionate and butyrate were efficiently utilized by Chlorella vulgaris and microalgae growth was higher than control condition. Similar trends were observed upon $NH_4-N$ and $PO_4-P$ consumption. Volatile fatty acids promoted Chlorella vulgaris growth, and nutrient removal efficiencies were highest when acetate was used, and butyrate and propionate showed second and third. From this work it could be said that using mixotrophic microalgae, in this work Chlorella vulgaris, fermented food waste leachates can be treated with high efficiencies.

• 상하수도학회지
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• 제27권1호
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• pp.69-76
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• 2013

Specific growth rate and removal rate of nitrogen and phosphorus of Chlorella sorokiniana, Chlorella vulgaris, Senedesmus dimorphus those are able to metabolite mixotrophically and have high nitrogen and phosphorus removal capacity were examined. Based on the results, one microalgae was selected and conducted experiments to identify the operating factors such as pH and aeration rate. The specific growth rate and phosphorus removal rate of C. sorokiniana significantly presented as $0.29day^{-1}$ and 1.65 mg-P/L/day, while the nitrogen removal rate was high as 12.7 mg-N/L with C. vulgaris. C. sorokiniana was chosen for appropriate microalgae to applying for wastewater treatment system and was cultured in pH ranged 3 to 11. High specific growth rate and removal rate of nitrogen and phosphorus were shown at pH 7 as $0.71day^{-1}$, 7.61 mg-N/L/day, and 1.24 mg-P/L/day, respectively. The specific growth rate examined with aeration rate between 0 and 2 vvm (vol/vol-min) highly presented as $1.2day^{-1}$ with 1.5 ~ 2 vvm, while the nitrogen removal rate was elevated with 0.5 vvm as 9.43 mg-N/L/day.

• 한국패류학회지
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• 제25권1호
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• pp.35-40
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• 2009

The trumpet shell Charonia sauliae is an endangered and valuable species with potential for aquaculture. For artificial propagation of C. sauliae, the effects of three different food microalgae on the development, growth, and survival rate of the larvae and spat were investigated. For the larval feeding experiments, we utilized six microalgae species as food sources, namely Pavlova lutheri, Tetraselmis suecica, Nannochloris oculata, Isochrysis galbana, Chaetoceros calcitrans, and Phaeodactylum tricornutum; for the larval and spat growth and survival experiments, we utilized T. suecica, C. calcitrans, and P. tricornutum. The results showed that the temporal digestion index (TDI) for the veliger larvae was significantly different for C. sauliae fed the different microalgae species (p < 0.05), that the T. suecica, C. calcitrans, and P. tricornutum cultivars were better suited for larval consumption (p < 0.05), and that the growth and survival of the larvae and spat were significantly influenced by food type, specifically P. tricornutum (p < 0.05). Further research is needed to evaluate the effects of other microalgae species, different algal concentrations, and biochemical composition on the growth and survival of C. sauliae.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2001년도 춘계 수산관련학회 공동학술대회발표요지집
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• pp.201-202
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• 2001

Mass culture of microalgae as feed for mollusc, crustaceans and fish is an important components of the mariculture industry (Metting Jr., 1996) Growth activator for tetraselmis suecica were screened in methanol and water soluble extracts of several seaweed tissues. Also examined in this study were change in growth rate, biochemical composition, and digestion efficiency, of T.suecica cultured with and without the most effective of these extracts, the water soluble component extracted form M. nitidium. (omitted)

• KSBB Journal
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• 제26권6호
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• pp.561-564
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• 2011

In this study, we carried out the development of high performance photobioreactor, which can be used to develop the biological $CO_2$ fixation technology as well as the renewable biofuels, the microalgae Botryococcus braunii. When B. Braunii was cultured in Anti-biofouling photobioreator, growth rate of it showed about 3 times higher than that of bubble column photobioreactor at the same conditions. In case of photobioreactor without bead, after 3 days culture time, biofouling occur rapidly in wall of the photobioreactor. However, with bead 5% (V/V), biofouling do not occur all experimental days.

• Fisheries and Aquatic Sciences
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• 제8권2호
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• pp.70-75
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• 2005

We investigated the effects of salinity and three food species of microalgae on the growth of three types of the rotifer Brachionus plicatilis, with the aim of improving mass culture of rotifers in hatcheries. Three types (large, small, and ultra-small) of the rotifer were cultured at 16 ppt and 32 ppt salinity with the green algae Chlorella ellipsoidea, Nannochloris oculata, or Tetraselmis tetrathele. The maximum density and specific growth rate were compared for each rotifer type. Ultra-small rotifers grew significantly faster at 16 ppt salinity than at 32 ppt, and C. ellipsoidea and T. tetrathele promoted significantly higher growth than did N. oculata. However, small rotifers grew significantly better at 32 ppt salinity than at 16 ppt, and small rotifers fed on N. oculata achieved the highest density at 1,185 individuals/ml. Large rotifers grew faster at 16 ppt salinity than at 32 ppt, with a diet of T. tetrathele resulting in the fastest growth. Each type of rotifer thrived under different regimens of microalgae and salinity.