Earticle

Chitooligosaccharides (COS) of three different molecular weight ranges (1– kDa, 3– kDa and 5–0 kDa) were investigated for their abilities against allergic reactions in RBL-2H3 cells. At the high concentration of 1000 μg/ml, COS with molecular weights of 1– kDa greatly attenuated the histamine and β-hexosaminidase release and intracellular Ca2+ elevation induced by calcium ionophore A23187, at the rates of 32% and 34% release and 37% elevation, respectively. Furthermore, the inhibitory activities of COS on calcium ionophore A23187 plus phorbol 12-myristate 13-acetate (PMA)-induced production as well as mRNA expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-4, and IL-6 were evidenced. Notably, the suppressive effects on the phosphorylation of extracellular signal-regulated kinases (MEK/ERK) and p38 kinase by COS were confirmed. These results indicate that COS could be used as an inhibitor in regulating mast cell-mediated allergic inflammatory responses.

C-type lectins play important roles in the non-self innate immune system of invertebrates. In this study, we isolated the full-length cDNA of the C-type Lectin like-domain (CTLD)-containing Protein, designated PtLP, from the hepatopancreas of the swimming crab Portunus trituberculatus, one of the most common edible crabs of East Asia. The full-length cDNA of PtLP was cloned through RT-PCR and rapid amplification of cDNA ends (RACE). The PtLP cDNA consists of 923 bp and encodes a polypeptide of 164 amino acids containing a well-conserved C-type lectin-like domain (CTLD). The deduced amino acid sequence of PtLP shows 29-36% amino acid sequence identity to other crustacean C-type lectin sequences. A phylogenetic analysis revealed that PtLP is in a large cluster together with black tiger shrimp PmAV, an antiviral protein of black tiger shrimp, and all of the C-type lectins from the various shrimps. Quantitative RT-PCR analysis showed that the PtLP mRNA was expressed highly in hepatopancreas and moderately in gills, hemocytes, and ovary of normal swimming crabs. In the present, the recombinant PtLP inserted in pTrcHis2 TOPO vector is expressed in E.coli and characterized.

An alginate lyase from Pseudomonas sp. KS408 was cloned and characterized. Recombinant E. coli harvested with alginate gene was expressed by IPTG induction and purified by using Ni-Sepharose affinity chromatography. Alginate oligomers obtained by degrading alginate with KS408 alginate lyase were analized by using FPLC and H-NMR. Peak profile from NMR showed that KS408 alginate lyase was polyM-specific lyase (β1-4 lyase, EC4.2.2.3). KS408 alginate lyase could cleavage between D-b-mannuronate and D-b-mannuronate linkage (MM) not D-b-mannuronate and L-α-guluronate linkage (MG). The molecular weight of oligoalginate products also analyzed with Electron-spray-ionization/Mass spectroscopy (ESI-MS). When polyM block was treated with KS408, four part of dimer and 1 part of trimer could be obtained. Acknowledgement : This work was supported by New &Renewable Energy R&D program(20093020090020) under the Korea Ministry of Knowledge Economy(MKE) and Korea Industrial Technology Foundation (KOTEF) through the Human Resource Training Project for Strategic Technology.

We previously identified novel AY30 antifreeze protein from psychrophilic arctic yeast, Leucosporidium sp. In this study, we developed an expression system allowing high-level production and efficient purification of recombinant AY30 (rAY30). We have succeeded in the cloning of AY30 gene and the gene product was efficiently expressed in Pichia pastoris. Our expression system comprises N-terminal secretion signal sequence to promote the secretion of rAY30. N-terminal sequencing of the secreted rAY30 revealed that the signal sequence is immediately cleaved from the polypeptide once it has been translocated into the culture media. A simple purification protocol for secreted rAY30 involved in three steps: anion-exchange chromatography, cold-finger, followed by size exclusion chromatography on Superdex 200 column. 10 mg of rAY30 was purified to 98% purity from 3 liter culture supernatant. Purified rAY30 was characterized using western blot, periodic acid–chiff (PAS) staining and circular dichroism method. Its molecular mass difference between glycosylated and unglycosylated rAY30 and PAS staining showed that rAY30 is a glycoprotein. Analysis of the antifreeze activity showed that glycosylated rAY30 and unglycosylated rAY30 exhibit similar activity. This result suggests that the glycan part of AY30 is not essential for antifreeze function. In addition, circular dichroism spectra analysis combined with molecular modeling studies demonstrated that AY30 adopts a left-handed β-helix fold with high percentage of β-stand (80%). In conclusion, an efficient production process for rAY30 has been developed including a highly efficient and stable Pichia pastoris secretion system and an efficient purification procedure, which could be used for further structural studies and industrial purposes.

Flocculation of three marine algae, Chlorella ellipsoidea, Dunaliella bardawil, and Dunaliella tertiolecta, were studied to optimize harvesting method for concentrating microalgae from microalgae mass culture. It is well known that the mass density of microalgae are usually very low and it is not economic to concentrate for the purpose of biodiesel production. To find out improved conditions for microalgae harvesting by chemical flocculation, various chemical flocculants, such as organic flocculants (aluminium sulfate, aluminium potassium sulfate, ferrous sulfate, ferric sulfate, ferric chloride, calcium hydroxide, sodium carbonate, sodium nitrite, and sodium aluminate), inorganic flocculant (polyacrylamide), biopolymer flocculants (chitosan and starch) were tested. Among the tested flocculants, ferric chloride, ferric sulfate, calcium hydroxide, aluminium sulfate, aluminium potassium sulfate, sodium aluminate, showed best performance.

Increased concentration of CO2 in the atmosphere has been considered to be one of the main causes of global warming. As a consequence of global warming many technologies are being developed for greenhouse gases mitigation. Chemical reaction-based CO2 mitigation approaches are energy-consuming and costly processes, and the only economical incentive is the CO2 credits to be generated under Kyoto Protocol. Biological CO2 fixation using photosynthetic organisms, especially microalgae, has been proposed as one of the possible methods for reducing CO2. In agriculture, kerosene oil and butane gas were normally used for heating sources and consequently CO2 gas was produced. This study investigated the potential of carbon dioxide fixation on microalgae for sequestration of carbon dioxide from flue gas generated during heating of green houses in the winter. Chlorella vulgaris was cultivated in the green house using CO2 sources were flue gases of kerosene oil and butane gas. The final cell concentration under flue gas was 25% lower than that under the control, while the average lipid concentration under flue gas was 12% higher than that under the control. In other words, the cultures under flue gas got more stress than the control. The results of FTIR analysis (Gas composition analysis) were indicated that flue gas contains SOX and NOX.

Phosphoenolpyruvate carboxylase (PEPCase, EC 4.1.1.31) is widely distributed and plays a cardinal role in all photosynthetic organisms. It catalyzes the conversion of HCO3 - concentrated by carbonic anhydrase (CA) into four-carbon organic acid oxaloacetate (OAA). And also PEPcase is the main anaplerotic enzyme providing OAA and/or malate, replenishing the tricarboxylic acid (TCA) cycle intermediates in all photosynthetic organisms and also in non-photosynthetic bacteria and protozoa [1]. So, Using these CA and PEPCase, the biorefinery system can be developed by genetic engineering. In this regards, we have tried to search and isolate CA and PEPCase from marine microalgae. In this study, two types of PEPCase were identified from marine green algae Dunaliella sp. and Dunaliella salina. The molecular cloning of the two PEPCase genes in Dunaliella salina (DsPEPC1, DsPEPC2) and one in Dunaliella sp. (DspPEPC1) were isolated, respectively. The predicted primary structure of DsPEPC1 (or DspPEPC1) of 975 amino acids is similar to the Class-1 type PPC1 from C. reinhardtii at 70% identity and 82% similarity [2]. The deduced DsPEPC2 of 1097 amino acids is also similar to the Class-2 type CrPPC2 at 56% identity and 67% similarity, respectively. In contrast, the deduced DsPEPC1 and DsPEPC2 polypeptides share only a 41% overall amino acid sequence homology. These results indicated that Dunaliella PEPC1 and PEPC2 are highly conserved in those of green microalge Chlamydomonase reinhardtii and Volvox carteri. The expression patterns of two PEPCases in Dunaliella salina have studied.

The optimal agitation speed and aeration rate for mass production of carboxymethylcellulase (CMCase) of B. amyloliquifaciens DL-3 by E. coli JM109/DL-3 were established in a 7 L bioreactor using the response surface method. The analysis of variance (ANOVA) of results from central composite design (CCD) indicated that highly significant factor ("probe>F" less than 0.0001) for cell growth and production of CMCase was the aeration rate. The optimal agitation speed and aeration rate for cell growth were 498rpm and 1.4 vvm, whereas those for production of CMCase were 395 rpm and 1.1 vvm. The optimal inner pressure in a 100L bioreactor for cell growth was 0.8 kgf/cm2, whereas that for production of CMCase was 0.6 kgf/cm2. The maximal production CMCase by a recombinant E. coli JM109/DL-3 under optimized conditions in this study was 871.0 U/mL, which was2.4 times higher than that by B. amyloliquifaciens DL-3.

Agar, which is accumulated in the cell walls of Red algae, such as Gelidium and Gracilaria is composed of agarose and agaropectin. In addition, agarose is composed of D-galactose and 3,6-anhydro-Lgalactopyranose with repeated structure. Agarase is agarolytic enzyme. This catalyzes the hydrolysis of agar and decomposes into agarooligosaccharides and neoagarooligosaccharides. The former is produced by α-agarase or acid catalysis. On the other hand, The latter is produced by β-agarase catalysis. In the previous study, agarase producing bacteria from the guts of spiny turban shells is isolated. For industrial application, the development of efficient culture condition and media composition is essential. This study sets a goal of both competitively mass production and the highest enzyme activity. Through one factor at a time(OFAT) method, the optimal temperature, pH, carbon source and the nitrogen source were determined. And then media composition was optimized by design of experiment(DOE). These results improved agarase production from Pseudoalteromonas sp. JYBCL 1.

In this study, two integrated system, composed of UV-photocatalytic reactor loaded with different photocatalyst media and fluidized biofilter in series, were constructed to compare their efficiency for the treatment of real textile wastewater. The real textile wastewater containing various dyes, surfactants, polyvinyl alcohol(PVA), hydrolyzed polyester and other recalcitrant organic substances, was fed to a fluidized biofilter, after which the fluidized biofilter-treated wastewater entered into UV/photocatalytic process. The return-sludge obtained from a textile wastewater treatment facility located in Daegu, was immobilized at the fluidized media in the biofilter and the photocatalytic reactor was filled with TiO2 coated-1) porous silica media or 2) glass bead media. For the case of TiO2 coated-porous silica media, the COD values of feed, biofilter-treated wastewater and the effluent from photocatalytic reactor were 1800ppm, 350-380ppm and 200-300ppm, respectively. For the case of TiO2 coated-glass beads media, the COD values of feed, biofilter-treated wastewater and the effluent from photocatalytic reactor were 1800ppm, 350-380ppm and 315-340ppm, respectively. Thus the COD removal efficiency of the integrated system with TiO2 coated-porous silica bead media was maintained at 83-89% while the COD removal efficiency of the integrated system with TiO2 coated-glass bead media was maintained at 79-86%. Moreover, for the case of TiO2 coated-porous silica media, the ADMI color values of feed, biofilter-treated wastewater and the effluent from photocatalytic reactor were 1300, 500-630 and 230-550ppm, respectively. For the case of TiO2 coated-glass bead media, the ADMI color values of feed, biofilter-treated wastewater and the effluent from photocatalytic reactor were 1300, 500-630 and 550ppm, respectively. Thus the color removal efficiency of the integrated system with TiO2 coated-porous silica bead media was maintained at 58-82% while the color removal efficiency of the integrated system with TiO2 coated-glass bead media was maintained at 58%. It is suggested that the type of TiO2 coated-media is important to determine the characteristics on the whole integrated system

Ethanol from seaweed, Saccharina japonica (Sea tangle, Dasima) was produced by the optimization of hydrolysis of macroalgae polysaccharide for the saccharification and simultaneous saccharification and fermentation (SSF) method. The seaweed was dried by hot-air and ground by hammer mill to 200 mesh s prior to the pretreatment. Saccharification was carried out by thermal acid hydrolysis using H2SO4 andIZE industrial enzyme, Termamyl 120 L. To increase the yield of saccharification, the isolation of marine bacteria was carried out. The optimal saccharification was carried out with thermal acid hydrolysis of 10% (w/v) seaweed slurry by 40mM H2SO4 and then the treatment of 1 g dcw/L isolated Bacillus sp. JS-1. The reducing sugar concentration and viscosity under the optimal saccharification procedure were 45.6±5.0 g/L and 24.9 cp, respectively. The yield of saccharification with the optimal condition from Saccharina japonica was 69.1%. SSF was carried out for the ethanol production. The highest ethanol concentration of 7.7 g/L with 33% of theoretical yield was obtained by SSF with 0.39 g dcw/L Bacillus sp. JS-1 and 0.45 g dcw/L yeast, Pichia angophorae KCTC 17574.

We investigated to improved glucose conversion yields from brown algae Sargassum sagamianum by high pressure steam process . It was found that sargassum sagamianum should consisting of polysaccharides, alginate, laminaran and cellulose, when used for bioethanol production. The marine Sargassum sagamianum was hydrolyzed in a compressed cell at 100~180℃ and 1~10 bar for 8min by using only water. The optimal pretreatment condition was determined as 180℃ and 10 bar for 8min, having 7.3(% w/w) and 2.1(% w/w) of glucose and xylose conversion yields, respectively. The sargassum sagamianum was hydrolyzed in a 180℃ temperature by 1% sulfuric acid pretreatment obtained glucose yield as 4.8(% w/w), xylose yield as 1.8(% w/w). High pressure steam process could be obtained for higher yields than 1% sulfuric acid process, it thought that the impact of the expansion of the interior cell of brown algae. These results implys that high pressure process by using only water could be used to efficiently hydrolyze Sargassum sagamianum, which results would help to increase the hydrolysis yield for marine algae.

In this study, the recycling integrated process composed of fluidized biofilter and UV-photocatalytic process as advanced oxidation process (AOP) was constructed to evaluate the efficiency and the comparability to the conventional wastewater treatment, for the treatment of real textile wastewater. The real textile wastewater containing various dyes, surfactants, polyvinyl alcohol(PVA), hydrolyzed polyester and other recalcitrant organic substances, was fed to fluidized biofilter with the stream recycled (recycle ratio=0.83) from a photocatalytic reactor, into which the fluidized biofilter-treated wastewater entered. The recycled stream from UV-photocatalytic reactor to the fluidized biofilter was designed to enhance the biodegradability of bio-recalcitrant organic chemicals from textile wastewater. The return-sludge obtained from a textile wastewater treatment facility located in Daegu, was immobilized at the fluidized media in the biofilter and the photocatalytic reactor was filled with TiO2 coated-glass bead media. The COD values of feed, biofilter-treated wastewater and the effluent from photocatalytic reactor were 1800ppm, 360-390ppm and 320-360ppm, respectively. Thus the COD removal efficiency of the integrated system was maintained at 80%, composed of the one of the fluidized biofilter(72-75%) and the one of photocatalytic reactor(5-8%). The ADMI color values of feed, biofilter-treated wastewater and the effluent from photocatalytic reactor were 1350, 630-660 and 570-615ppm, respectively. The color removal efficiency of the integrated system was maintained at 55%, composed of the one of the fluidized biofilter(45%) and the one of photocatalytic reactor(10%). It was noticeable that the color removal efficiency of UV-photocatalytic process was almost twice the COD removal efficiency of the same process. The space loading of this study is calculated as 1.22 kg COD/day/m3, which is almost six times of the space loading value of conventional activated sludge reactor.

Ethanol production was performed in simultaneous saccharification and fermentation (SSF) processes from a seaweed, Undaria pinnatifida (Sea mustard, Miyuk). To obtain a high ethanol yield, pretreatment conditions were optimized and marine bacteria treatment was performed. Pretreatment by thermal acid hydrolysis was carried out at different sulfuric acid concentration of 40.0-187.6mM H2SO4, treatment time of 15-60 min and solid contents of seaweed powder with 10-20% (w/v). Optimal pretreatment conditions were determined as 75mM H2SO4 and 13% slurry at 121℃ for 60 min. A maximum reducing sugar of 28.65 g/L and viscosity of 34.55 cP were obtained. The pretreated seaweed was further saccharified by the addition of 0.98 g dcw/L isolated marine bacteria dispersion after neutralization by 5N NaOH. The mixture were incubated at 30℃ with 200 rpm for 4 days. Reducing sugar of 41.73 g/L and viscosity of 32.18 cP were obtained. SSF was carried out to produce ethanol. The ethanol concentration of 3.26 g/L and viscosity of 22.66 cP were obtained by adding 0.98 g dcw/L isolated marine bacteria and 2.16 g dcw/L yeast, Candida tropicalis KCTC 7212, in SSF processes.

Mortality of larvae of Spodoptera exigua by various entomopathogenic fungal strains were examined to select an efficient strain for the control the pest. To determine the virulence of the fungi, 108 conidia/㎖ｦ suspension of each strain was sprayed onto 10 larvae on a dampened filter paper in a petri-dish. Mortality of larvae was recorded daily over 15 days and strain No. 78, 216, 218 and 500 among 28 different strains of entomopathogenic fungi showed relatively high mortality of larvae at temperature of 25℃ and relative humidity of 70%. The aerial conidia production of the various fungal strains by solid state fermentation were also examined using several solid media. Excellent production of conidia was accomplished by using wheat bran powder for the strain No. 218, polished rice for the strain No. 198, and barley for the strain No. 218, respectively. From the results, strain No. 218 was selected as the best strain for production of conidia as well as control of larvae.

In this study a batch reactor was used to investigate the nitrous oxide emission from nitrification using activated sludge at different concentrations of ammonia. It was also attempted to investigate the relative contribution of different pathways involved in emitting nitrous oxide by using two types of wastewaters, with and without organic compounds during nitrification process. In addition, the steps of nitrification responsible for emitting nitrous oxide were identified using nitrification inhibitors. N2O emission from the synthetic wastewater reached 1.4, 2.4, 3.8 and 4.3 mg N2O– from 5, 12.5, 25 and 50 mg NH4+-N respectively. The real wastewater emitted 2.1, 2.9, 4.0 and 5.3 mg N2O– from 5, 12.5, 25 and 50 mg NH4+-N. The N2O emission from activated sludge with synthetic wastewater was found to be 0.065 - 0.12 kg N2O– per kg N (oxidized NH4 +), while it was 0.1 –0.42 kg N2O– per kg N (oxidized NH4 +) with the real wastewater. The results showed an increase of 5 - 33% in N2O emissions when real wastewater was used. Under the ammonia oxidation inhibition by allylthiourea produced almost no N2O while the control experiment produced 0.3 mg N2O-N. Under the inhibition of nitrite oxidation by azide, which selectively blocks nitrite oxidation, emitted 1.5 mg N2O– which is significantly higher than that of the control. This indicates that the second step of nitrification (nitrite oxidation) did not play any significant role in the reduction of nitrous oxide emission. Moreover, nitrite accumulation by blocking nitrite oxidation activates N2O production. It is thought that nitrite favors the production of N2O as it could inactivate nitrous oxide reductase. This indicated that N2O emitted during the ammonia oxidation or due to heterotrophic denitrification as nitrite and organics were also present in the system. Nitrite seems to be the key components in microbiological N2O production pathways.

Hydrogen energy is one of best clean energy and hydrogen energy not only reduced the reliance on traditional energy resources but also avoids causing environment pollution of burning fossil fuel. This research attempted to produce bio-hydrogen from marine algae by sludge from anaerobic digester in a wastewater treatment plant. Marine algae, the colloquial term for a number of macro algae, have enormous potential as a source for bioenergy. Seaweeds can grow faster with higher CO2 fixation ability than land plants and can be cultivated on vast tracts of sea by sunlight without any nitrogen-based fertilizer. Galactose, the main sugar monomer of marine algae, was easily converted to hydrogen by dark fermentation. In this study, the authors investigated the feasibility of Bio-hydrogen production from marine algae by dark fermentation. Main focus is as follows. (1) Effect of galactose concentration on the hydrogen production rate. (2) Effect of glucose concentration on the hydrogen production rate. This work was supported by a grant (2010301009001-A-12-1-000) from Korea Institute of Energy Technology Evaluation and Planning, Ministry of Knowledge Economy, Republic of Korea.

Carbon dioxide (CO2) has been regarded as a main green house gas affecting global warming, and thus enormous efforts have been focused in order to make a balance between generation and fixation of carbon dioxide. We developed a new electrochemical bioreactor to cultivate chemoautotrophic bacteria capable of growing with carbon dioxide and electric energy. In this study, bacterial community grown in the electrochemical bioreactor was analyzed by pyrosequencing technique. We selected two main predominant species, Acromobacter and Alcaligenes, and are studying their efficacy for the fixation of carbon dioxide.

Kinetic simulation model of metabolites behavior is needed for an optimal design of bioreactor and developing of operation strategy. However, the estimation of dynamic behavior of metabolites in Acetone-Butanol-Ethanol(ABE) fermentation by clostridum is difficult, because of the complexity of metabolic pathway due to two distinct characteristic phases(acidogenesis, solventogenesis), substrate inhibition, and product inhibition. In this study, we developed the kinetic simulation model of ABE production which is based on the metabolic pathway by butyrate kinase knock-out clostridium. We estimated the kinetic parameter in this model using the experimental data.

Microalgae are photosynthetic microorganisms being capable of converting carbon dioxide and water to organic macromolecules such as lipids, polysaccharides and proteins under light conditions. The polysaccharides can be hydrolyzed to obtain reducing sugars such as glucose, which could be used as bioethanol feedstocks. The lipids component (especially triacylglycerols) can be extracted and utilized as a biodiesel feedstock. In this study, the effects of enzymatic hydrolysis on the glucose production and subsequent lipid extraction from microalgal biomass (Chlorella vulgaris sp.) were investigated. The microalgal cells were hydrolyzed by cellulase and then their lipid fractions were extracted using various organic solvents such as hexane, methanol and chloroform. Optimal pH and temperature for the enzymatic hydrolysis were pH 4.8 and 50oC, respectively, and maximal efficiency was estimated at 85.3%. After the enzymatic hydrolysis, the lipid extraction yields by the organic solvents were improved by 1.23- to 1.73-fold depending on the solvents compared to those without the hydrolysis process.

TiO2 nanoparticles were synthesized using a chemical vapor condensation (CVC) method, and their physicochemical properties were characterized to optimize the synthesis conditions for antibacterial activity. The antibacterial activities of CVC-TiO2 nanoparticles and commercialized TiO2 nanoparticles (P25, Deggusa) were investigated according to UV exposure time and amount of photocatalyst. We found that the specific surface area and the crystallinity of CVC-TiO2 nanoparticles were varied depending on synthesis temperature and precursor vapor concentration. As a result, the CVC-TiO2 nanoparticles showed a higher specific surface area and better crystallinity than that of P25-TiO2. More importantly, CVC-TiO2 nanoparticles generated a larger amount of hydroxyl radicals than P25-TiO2. Consequently CVC-TiO2 nanoparticles were more effective as an antibacterial photocatalyst than P25-TiO2 under irradiation with UV light. Based-on these results, the optimum synthetic conditions of CVC-TiO2 nanoparticles for bactericidal effect was found.

Previously, we suggested a multiphase electrode microbial fuel cell (multiphase MFC) to harvest energy using organics in different two phases (water and sediment) of a water body contaminated with waste organics. The MFC consists of floating electrode (FE) located in surface layer of the organic-fed water, mid-electrode (ME) placed in the water, and sediment electrode (SE) embedded in the sediment. Throughout the previous study it was turned out that when the water phase is polluted with waste organics, the electrons produced in ME and SE of the MFC are consumed in the FE, thus coupled current is produced. In this study, we investigate and report a working mechanism on how the multiphase MFC can generate increased power by using organics in the different two phases. Firstly, we found out that the MFC increases current and voltage by interaction of ME with SE, leading to increase in power output. In addition, during the increased power production, most exchange of the electrolyte among the electrodes in the MFC system occurred between FE and ME. Hence, it can be inferred that the ME and FE act as enlarged one anode electrode. These results could provide a clue for benthic MFCs, having operational limitations, to optimize the performance.

Nitrogen removal process is a process by which certain species of bacteria under anoxic conditions reduced nitrate to nitrogen gas which can be released from water to the atmosphere. And unlike other nitrogen compounds, the nitrogen gas is relatively unavailable for biological growth and has no significant effect on environments. Nitrate has lots of harmful effect to environments and human body. At first, nitrate cause eutrophication in water system. Next, nitrate has toxicity to human body. The nitrate causes methemoglobinemia (blue baby syndrome) to infants. And in other research, nitrate could theoretically be transformed into N-nitrosamines which could cause hepatic tumours. For these reasons, many kinds of nitrate removal process have been developed and several methods for nitrate removal from wastewater are being used. Chemical, physical, electrical, and biological methods have been developed In this research, electro-enzymatic denitrification system was developed. And the metabolic pathway will be proposed. Also, the mathematical model equation will be proposed and analyzed.

In 2006, the price of palm oil was $0.52/L, but the microalgal biodiesel cost was $2.80/L, fivefold higher than plant biodiesel price. For the economical feasibility of microalgal biodiesel, it is mandatory to reduce the harvest cost which occupies ca. 20% of total microalgal biodiesel production and introduce the integration system of cultivation and harvest process. There have been various algal harvest methods for the microalgal biodiesel production, organic/inorganic coagulation, sedimentation, filtration, flotation, and so on. Until now, Electrolytic technology have been mainly utilized for elimination of microalgae in eutrophicated lake and river. This technology, compared to other microalgae removal technologies, shows better economical feasibility and lower contamination. Due to other low economical microalgae harvest means, Electrolytic technology draws a attention as new alternative recently. In this study, some operating factors for microalgal harvest was investigated. Through electrolysis of water, positive-charged coagulants and O2 microbubbles are generated at anode and H2 microbubbles are generated at cathode in EC technology. Coagulants make microalgae destabilized forming microalgae flucs. After flocculation, microbubbles float microalgae flucs for harvest

The unavoidable depletion of fossil fuels and the steady increase of the world population have strengthened the need of alternative energy sources. Currently, many alternative energy sources including solar, wind, nuclear, hydrogen and biofuels have received much attention; however, biofuels is far more economical and feasible in comparison to the other available sources. Generally, biofuels from biomass can be classified according to three generations. One of the three generation biofuels are produced from low input and high yield feed stocks such as improved plants and marine biomass. Marine biomass has high yield species such as microalgae and macroalgae. In this research, the anaerobic digestion of red algae (Gelidium amansii) was investigated in batch culture. By using macroalgae that have low content of lignin, reducing the pretreatment cost of lignin removal and increasing the efficient are possible. We selected candidate experiments regarding the effect of ammonia pretreatment in anaerobic digestion. The effects of ammonia pretreatment at drying temperature on VFA production were researched

Microalgae can be used to produce bioenergy in several ways. One of the most efficient ways is through the utilization of the algal oils to produce biodiesel. Microalgae are traditionally cultivated either in open ponds or enclosed systems. However, there have been limitations due to the production methods to grow and harvest microalgae. An attached microalgal growth using wild benthic microalgae in outdoor cultivation was evaluated in this study. The first part of the work evaluated the feasibility study of wild benthic microalgae onto the substrata for the attachment in natural filtered seawater. The results showed that wild benthic microalgae could produce feasible high biomass yield. The benthic microalgae of 0.87±0.05 g dcw/L were produced with crude oil and triacylglycerol content of 10.9% and 7.2% (w/w), respectively. In the second part, two-stage cultivation was carried out with nitrogen and/or salinity stress for triacylglycerol accumulation. Triacylglycerol content of microalgae increased from 7.2% to 19.3% (w/w) on 2nd day in two-stage process. This study provides the pictures of future microalgal oil production.

Endocrine disrupting chemicals (EDCs) have been known as health threatening compounds and much attention has been paid in a research related with detection and/or removal from food sources and living environment. Amitrol, classified as one of EDCs, is hard to be detected and removed due to its chemical characteristics such as small molecular weight, low reactivity and high solubility. Some of organic compounds were investigated to find the corresponding binding peptides to those by biopanning protocol. However, peptides with affinity to amitrol remained to be searched for because amitrol is hard to be used as a target of free form or immobilized form in common biopanning protocol. In our experiment, amitrol was successfully immobilized on CDI monolithic column with the presence of catalyst and hence was able to be applied as a target component in biopanning. Chromatic biopanning was carried out as a fast and convenient method for the selection of peptides with high affinity to amitrol. Chemical and physical methods were combined in elution step to improve the selection efficiency for strong binders. After multiple rounds of negative screening and positive screening, high affinity peptide sequences were isolated from initial peptide libraries and further examined to finally obtain strong and specific peptide sequences. Applications of these peptide sequences can be widened from bio adsorption to biosensor and are under our studies.

Barley straw is an abundant agricultural residue which can be used as a raw material for bioethanol production. In the present study thermostable fusion yeast, Kluyveromyces marxianus CHY1612 was used in simultaneous saccharification and fermentation (SSF) of pretreated barley straw. In the SSF process using cellulosic biomass, we obserbed enhanced glucose conversion yield from biomass and improved ethanol productivity. And we investigated the application of temperature-shift strategy for optimization of conversion yield and productivity in the SSF process

Chlamydomonas reinhardtii is a green alga which was used as a H production. It was thought that it has lots of advantages which are suitable solution of energy crisis. That makes it studied a lot, so this alga has much important information for a further study. For advanced usage of microalgae to produce biodiesel, economical efficiency was and is the most important factor. In this study, Chlamydomonas reinhardtii was cultivated in the harsh condition which is shortage of phosphorus, nitrogen source. By reducing the nitrogen and phosphorus sources in the medium, costs of making the medium was decreased. Nitrogen and phosphorus sources were controled 20%, 40% and 60% respectively as compared with standard TAP medium. Growth rates and lipid profiles varied with initial concentration of nutrients. This results will help medium condition for the massive cultivation to be optimized.

Mircoalgae require proper conditions for the cell growth. Since microalgae are photosynthetic, proper light source, carbon dioxide concentration, water, and inorganic salts are required for optimal growth conditions. In this study, various light intensities and nitrate concentrations were tested with conditions of 20℃, 24:0 L:D cycle and 2.5 L/min aeration rate in 20 L batch culture. It took 5 days to reach the stationary phase for the culture of T. suecica with the light intensities of 108.9 and 133.1 μmol/m2/s with biomass of 0.89 and 0.88 g dcw/L, respectively. And, biomass productions of 1.07 and 1.00 g dcw/L were obtained with the nitrate concentrations of 18.55 and 24.74 mg/L, respectively. Nitrate was consumed by T. suecica of all tested groups within 5 days after the inoculation. Two-stage culture process through nitrate depletion led to increase oil contents from 7.6 % to 17.3 % (w/w) and contents of C16∼�18 fatty acids from 540.2 mg/g oil to 720.5 mg/g oil at 4th day after nitrate depletion. The biomass production and oil content of T. suecica was enhanced by the optimization of growth conditions and 2-stage culture process.