• ALGAE
• /
• 제22권3호
• /
• pp.229-234
• /
• 2007

This study was to determine the extent of bacteria contamination and resistance to various antibiotics used commonly in microalgal culture. Seven different dose levels of chloramphenicol, dihydrostreptomycin sulphate, neomycin, penicillin G, streptomycin sulphate, penicillin G + streptomycin sulphate, and penicillin G + streptomycin sulphate + chloramphenicol were added to each culture of microalgae. The lethal effects on microalgae and bacteria were the highest in chloramphenicol and the lowest in penicillin G. The axenic culture of bacillariophyceae and dinophyceae was more difficult than that of chlorophyceae and haptophyceae because of their complicate external morphology. The efficient antibiotics and their concentrations for axenic cultures varied with microalgal species. The optimum quantity for antibiotic treatments were 2,000 ppm of dihydrostreptomycin for Chlorella ellipsoidea, neomycin 500 ppm of Isochrysis galbana and Heterosigma ahashiwo, hloramphenicol 500 ppm of Cyclotella didymus, and dihydrostreptomycin sulphate and neomycin 6,000 ppm of Thalassiosira allenii.

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

• Journal of Biosystems Engineering
• /
• 제24권1호
• /
• pp.9-18
• /
• 1999

This study was performed to investigate the optimum microalgal culture conditions using flask culture and to find the feasibility of using the flue gas of the rice husk incinerator for cultivating the microalgae. The optimum initial pH of media was 4.5 for the microalgae culture, and the intermittently illuminated culture was more effective than the continuous illuminated culture. Thus, the balance between photosynthesis and formative metabolism must be considered thoroughly to cultivate microalgal cells. The optimum CO2 concentrations were in the range of 7 to 10%, and the optimum temperature was about 35$^{\circ}C$ in both the daytime and the nighttime for the culture. When flue gas of the rice husk incinerator was applied to the microalgae culture using stirred photobioreactor, the dry cell weight was 0.026 g dry biomass/hr$.$l. The results obtained in experiments indicated that the flue gas was effective for microalgae culture without any limitations.

• 공업화학
• /
• 제27권1호
• /
• pp.1-9
• /
• 2016

미세조류와 박테리아의 공배양 시스템은 두 미생물종이 공생적 관계가 있다면 한 배양기에서 BOD와 영양염류의 동시 제거가 가능하다. 이때 영양염류는 미세조류의 바이오매스 성분으로 전환된다. 이 총설은 미세조류와 박테리아의 공생적 혼합배양을 이용한 하폐수처리, 특히 질소와 인의 제거에서의 중요성과 최근의 연구동향을 살펴보았다. 미세조류는 광합성을 통해 산소를 발생시키고 박테리아는 이 산소를 전자수용체로 이용하여 유기물의 산화분해에 활용할 수 있다. 호기성 박테리아가 유기물을 산화할 때 발생되는 $CO_2$는 미세조류의 탄소원으로 섭취되어 탄소동화작용에 사용된다. 미세조류와 박테리아의 공배양은 상호 이익이 될 수도 있고 저해가 될 수도 있으므로 지속적인 영양염류 제거를 위해서는 상호 이익이 되는 공생적 관계가 필수적으로 요구된다. 이를 위해서는 하폐수처리에 사용되는 상용적인 두 미생물 종의 선택이 중요하다.

• 상하수도학회지
• /
• 제25권3호
• /
• pp.307-312
• /
• 2011

The potential of algal-bacterial culture was investigated for advanced treatment of animal wastewater. Fed-batch experiments were carried out to examine treatability of nitrogen and phosphorus in different microbial consortium: Chlorella vulgaris, activated sludge, three microalgae strains (Scenedesmus, Microcystis, Chlorella) and Bacillus consortium, and three microalgae strains and sludge consortium. Single culture of C. vugaris showed the better efficiency for nitrogen removal but was not good at organic matter and phosphorus removal compared with activated sludge. Three microalgae and Bacillus consortium was best culture among the culture and consortium for pollutants removal tested in this experiment. Effect of $CO_2$ addition was studied by using three microalgae and Bacillus consortium. $CO_2$ addition enhanced T-P removal efficiency up to 60%. However, removal efficiencies of T-N and ammonia nitrogen reduced on the contrary.

• 한국양식학회지
• /
• 제5권1호
• /
• pp.81-91
• /
• 1992

해산동물의 종묘생산시 초기단계의 먹이로써 미세조류의 배양은 매우 중요하다. 그러나 자연으로부터 먹이생물로써 필요한 미세조류를 순수분리하여 순종을 보관하는 일은 일반 양식 업자나 이 분야에 종사하지 않는 연구자에게는 매우 어려운 일이다. 따라서 미세조류를 필요로 하는 사람들에게 순종의 미세조류 strain을 공급할 수 있는 은행의 설립이 필요하다. 본 연구에서는 capilla교 pipette법, 한천도말법, 희석법을 이용하여 한국연안에서 80종의 미세조류를 분리하였다. 현재 부산수산대학교 양식학과 실험실에서 확보 배양중인 117종의 미세조류의 배양현황을 보고하였다.

• 한국물환경학회지
• /
• 제28권6호
• /
• pp.796-803
• /
• 2012

Potential feasibility of nutrients removal and biofuel production with microalgae was evaluated in batch culture. Distribution of microalgae in fresh water including reservoir and river was investigated to search for the species with high content of lipid that could converted into biofuel. Green algae, Chlorella and Scenedesmus sp., these are known as species containing high lipid content for biodiesel production, were observed in both summer and autumn season. However another highly lipid-containing species, botryococcus sp. was not observed in this study. In mixed culture of microalgae using synthesized wastewater medium, green algae were found to be dominant, comparing to other species of diatoms and blue-green algae. And microalgae were also capable of removing nitrogen and phosphorus in batch experiments. During the culture period of 14 days, removal efficiencies of nitrate and phosphorus were 30% and 82%, respectively. Furthermore, content of the intracellular lipid extracted from algae cell was as favorable as 12-30% in the mixed culture where Scenedesmus and Chlorella sp. were dominant. Therefore the mixed culture of microalgae could be applied to biofuel production and tertiary wastewater treatment, even though there are economic barriers to overcome.

• KSBB Journal
• /
• 제26권2호
• /
• pp.143-150
• /
• 2011

The aim of the study was to optimize harvesting method for concentrating microalgae from microalgae mass culture. It is well known that the mass density of microalgae is usually very low and these are small size (5-20 ${\mu}m$) in the culture medium. It is essential that microalgae is harvested and concentrated economically for economical biodiesel production from microalgae. In this study, to determine optimized conditions for microalgae harvesting by chemical flocculation. Flocculation of three algae, Chlorella ellipsoidea, Dunaliella bardawil, and Dunaliella tertiolecta, was performed using various chemical flocculants, such as inorganic flocculants (aluminium sulfate, aluminium potassium sulfate, ferrous sulfate, ferric sulfate, ferric chloride, calcium hydroxide, sodium carbonate, sodium nitrite, and sodium aluminate), organic flocculant (polyacrylamide), and biopolymer flocculants (chitosan and starch). The results indicated that aluminium based inorganic flocculants is suitable for microalgae harvesting such as Chlorella ellipsoidea, Dunaliella bardawil, and Dunaliella tertiolecta. The results also recommended that flocculant doses, agitation speed, agitation time, sedimentation time for economical microalgae harvesting method using chemical flocculants.

• ALGAE
• /
• 제24권4호
• /
• pp.205-212
• /
• 2009

Molecular genetic tools are widely used to learn more about the identical characterization of obscure microalgal strains. At the Korea Marine Microalgae Culture Center (KMMCC), the authors deduced the genetic relationship of 41 strains of the genus Tetraselmis by analysing a small subunit ribosomal DNA (18S rDNA) sequences. Forty-one strains were seperated into five groups, which showed over a 98-99% similarity to Tetraselmis striata or Tetraselmis sp. Tsbre. Also, 13 strains among them had an identical genotype to Tetraselmis striata while 5 strains had with Tetraselmis sp. Tsbre, respectively. The mean size of each strain generally showed the tendency of different variation according to the groups.

• ALGAE
• /
• 제24권4호
• /
• pp.257-265
• /
• 2009

Marine microalgae are a key diet component in finfish and shellfish aquaculture. Cryopreservation of the microalgae is suggested by many other studies as the best method for long-term storage. To test cryopreservation efficacy, 19 taxas of marine microalgal species were examined. In the first experiment we compared dimethylsulfoxide ($Me_2SO$) and glycerol, which are most widely used as cryoprotectant agents (CPAs). The cryopreservation comprised two freezing procedures. Firstly, the samples containing the CPAs were kept at $4^{\circ}C$ for 10 min before being plunged into liquid nitrogen ($-196^{\circ}C$). Secondly, samples containing CPAs were pre-cooled ($-1^{\circ}C$ $min^{-1}$ to $-80^{\circ}C$ before being plunged into liquid nitrogen. Most of the species were successfully cryopreserved using $Me_2SO$, whereas the Prasinophyceae (T. striata and T. suecica) were successfully cryopreserved using glycerol. In general, the cooling method had no influence on the survival of the microalgae except in the case of the Tetraselmis species. In the second experiment, the cultured solution was divided before cryopreservation into concentrated and non-concentrated groups to identify the effect of cell density during cryopreservation. After 12 months of storage, the samples were again divided into centrifugation and non-centrifugation groups to learn the effect of $Me_2SO$ on the culture. Viability and growth of the microalgae were not influenced by cell density or the centrifugal removal of the $Me_2SO$ after thawing.