Earticle

Hydroxy fatty acids are considered as important value-added products for industrial application because of their special properties such as higher viscosity and reactivity. The new bacterial isolate Pseudomonas aeruginosa had been reported to produce mono-, di-, and tri-hydroxy fatty acids from different unsaturated fatty acids. Of those, 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) and 7,10,12-trihydroxy-8(E)-octadecenoic acid (TOD) were produced from oleic acid and ricinoleic acid, respectively. Based on the postulated common metabolic pathway involved in DOD and TOD formation by PR3, it was assumed that palmitoleic acid containing a singular 9-cis double bond, common structural property sharing with oleic acid and ricinoleic acid, could be utilized by PR3 to produce hydroxy fatty acid. In this study, palmitoleic acid was used as substrate for production of hydroxy fatty acid by PR3 and it firstly confirmed that PR3 could produce 7,10-dihydroxy-8(E)-hexadecenoic acid (DHD) with 23% yield from palmitoleic acid. In addition, the nutritional and environmental conditions were optimized to achieve higher production of DHD.

Acer tegmentosum Maxim., a herbal species grown in China and Korea is mainly treated as a medicinal plant and the dried aerial parts have been traditionally used for the treatment of hepatitis, liver cirrhosis, hepatic cancer, leukemia, diabetes mellitus, renal necrosis and edema. Reactive oxygen species, such as O2-, H2O2, and ·OH, mediate reactions which can result in the damage of critical biological molecules including DNA and cellular protein. In this study, the extracts of Acer tegmentosum Maxim. with hot-water, ethanol, methanol, and acetone were found to show the antioxidative and hepatoprotective effects in vitro. The cell lines used were HepG2 E47 cells that expressed human CYP2E1 and HepG2 C34 cells which did not express CYP2E1. No cytotoxicity was shown in MTT assay. The cell viability was measured to decide the proper sample concentration. Antioxidant activities by extracts from Acer tegmentosum Maxim. were investigated by the 2', 7'-Dichlorodihydrofluorescein diacetate(DCFDA)assay and GSH assay.

Currently, there is increasing interests about health drinks such as fruit juices and plant extracts prepared with heat under pressure. However, fruit juices and plant extracts contain high quantity of sucrose. After drinking, the sucrose remains in mouth may cause tooth decay and obesity by high-calories. To make low-calorie and sweet juices and extracts,, we developed method to make new functional fruit juices and plant extracts having sucrose concentration and high content of oligosaccharides by using dextransucrase prepared from Leuconostoc mesenteroides. In case of orange juice, 8.9 U/ 100 ml of dextransucrase was added and reacted at 16°C for 20 hr. The sucrose content was reduced from 39.6% to 6.02% and oligosaccharide content increased up to 41.6% in juice. In case of arrowroot extract, 16.8 U/ 100 ml of dextransucrase was added and incubated at 16°C for 4 hr. The sucrose content was changed from 56.63% to 5.77% and oligosaccharide content became 65.87% in extract. The enzyme reacted orange juice and arrowroot extract showed 91.15% and 89.60% inhibition effect compared to control (the original orange juice and arrowroot extract), respectively, for the insoluble glucan formation by mutansucrase produced from cariogenic Streptococcus mutans. From this result, the newly synthesized functional fruit juices and plant extracts containing low sucrose concentration and high content of oligosaccharides may contribute in positive for dental health. Studies about the prebiotic effects of those new fruit juices and plant extracts are in progress and will be discussed during symposium.

A new xylanase gene, KRICT PX3, isolated from Paenibacillus sp. HPL-003 (KCTC18179P), has been cloned and expressed in Escherichia coli. This gene encodes 540 amino acid residues (1,620bp) including 179 amino acid residues of a signal peptide, and the deduced amino acid sequence of KRICT PX3 showed 48% identity to endo-1,4-b-xylanase (YP_001817989) from Opitutus terrae PB90-1 among the xylanases of Glycosyl hydrolase 10 superfamily. Purified recombinant xylanase KRICT PX3 showed an thermostable, wide pH spectrum, and high activity on the different-origin of xylan. The specific activity of the purified xylanase KRICT PX3 at pH 7 and 50oC was 125 U, and exhibited Km and Vmax values of 0.2 mg/ml and 153.8 U/mg on birch wood xylan, respectively. This enzyme has a wide pH spectrum of pH 5 to pH 11. Optimum temperature was estimated at the range of 50~60oC and it was stable for 24 hrs at 50oC, however, easily lost the activity at 60oC after 20 min. Most salts did not significantly change the enzyme activity, and also ethylenediamine tetra-acetic acid, 2-mercaptoethanol, phenylmethanesulphonyl fluoride, and furfural were not influenced on the enzyme activity at 1 mM, however, Cu+2, Zn+2, Fe+2, and EDTA was slightly inhibited the enzyme activity. Thin layer chromatography analysis showed that the enzyme released a mixture of hydrolysis products including xylobiose, xylotriose and some of xylooligomers from birchwood xylan. Further research on the practical application will be necessary for the industrial usage.

For the assessment of apple flower leaf extract (AFE) as a functional material, the content of total phenolic compounds, whitening and antioxidant activities and nutritional components of AFE were analyzed. The AFE contains 57.52% of carbohydrate, 23.23% of crude protein and 4.35% of crude lipid, based on dry matter. The content of total phenolic compounds was measured as 1218.94 ㎍/㎖, and antioxidant activities and whitening activities as 74.85% and 59.18% at a concentration of 250 ㎍/㎖ in 70% ethanol extract, respectively. In conclusion, it is suggested that AFE could be used as an active ingredient for cosmetic products and valuable nutrient source.

Peptide aptamers that recognize inorganic materials are attracting increasing attention in the field of nanobiotechnology. This is because these peptides can be used not only to allocate various molecules on patterned substrates but also to form nanocrystals of inorganic materials under ambient conditions.1 TiO2 nanoparticles are widely used for many applications including photo-catalysis, photo-voltaics, energy storage and so on. The peptide-directed room-temperature formation of TiO2 nanoparticles can be an attractive alternative to higher-temperature synthetic methods.2 However, the underpinning mechanism for peptide driven biomimetic TiO2 synthesis remains still unclear and it has a long way to go before producing crystalline TiO2 with controlled nanostructure conducive to practical device applications. In the present study, we used STB1 (-CHKKPSKSC-, a constraint heptapeptide cognitive of TiO2) and its derivatives (i.e. point mutants of STB1 and STB1 fused with the tail peptide sequence of R5 reported elsewhre3) to explore a strategy for controlling the morphology (i.e. size and shape) of TiO2 precipitate in various conditions (e.g. peptide concentration, buffer composition, pH of buffer solution). Furthermore, the effect of peptide local structure (i.e. linear vs constraint form) on the morphology of biomineralized TiO2 precipitate was investigated. All the nanoparticles synthesized were characterized by energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). It was found that kinetics of TiO2 biomineralization is a key to determine the size of TiO2 nanoparticles: faster kinetics give rise to smaller nanoparticles. However, the kinetics of TiO2 particle formation exhibited little effect on the shape of particles, hence resulting in spherical nanoparticles with interconnected one another. Interestingly, the local structure of peptide molecules was found to affect the shape of TiO2 precipitate, giving rise to spherical nanoparticles with the use of constrained peptide sequences and planar interconnected precipitates with linear form.

Seaweeds have been attracted recently as multifunctional foods for maintaining human health. So, this study was carried out to verify immune enhancing activities of polysaccharide from Sargassum thunbergii(STP), edible brown seaweeds. Mice (n=5) were orally administered with STP every day for 4 weeks. Peyer’s patch, spleen and peritoneal macrophages were harvested from STP supplemented mice. It was confirmed that the oral administration of 10 and 100 mg/kg.BW STP enhanced proliferation abilities of peyer’s patch cells, splenocytes, and peritoneal macrophages. The IFN-γ, IL-6 as well as IgA secretion of peyer’s patch cells were significantly increased by STP. In addition, the splenocytes from STP administered mice produced substantially more IFN-γ and peritoneal macrophages secreted more IL-6 and IL-1β compared to PBS administered mice. In conclusion, it is considered that the oral administration of STP could strengthen immune reactions through stimulating an intestinal immunity.

Many investigators have tried to look for atopic dermatitis medicine from natural resources lately because the occurrence of atopic dermatitis has been continuously increasing. Therefore, an aim of this study is to examine inhibitory effects of pine gnarl water extracts (PGWE) on atopic dermatitis. To conduct this experiment, PGWE was added to splenocytes obtained from OVA-immunized mice for an in-vitro test. In addition, an anti-atopic dermatitis test was carried out by spreading PGWE on the dorsal skin of 2,4dinitrochlorobenzene (DNCB)-induced balb/c mice. It was verified that the IFN-γ, IL-4 and total IgE secretion was suppressed when PGWE was added to splenocytes obtained from OVA-immunized mice. For anti-atopic dermatitis test, PGWE alleviated symptoms of the erythema, crust and dryness in DNCB-induced mice. Furthermore, the IFN-γ, IL-4 and total IgE secretion of the group treated with PGWE in splenocytes and sera considerably diminished compared to the positive control. Through these results, we can conclude that PGWE can inhibit allergy and atopic dermatitis by modulating IFN-γ, IL-4 cytokine and IgE secretion.

Reactive oxygen species (ROS) have been shown to cause DNA damage, denaturation of protein, loss activity on anti-oxidative enzyme and lipid peroxidation. Thus, ROS are associated with tissue damage and the prime contributing factors for inflammation, diabetes, aging, cancer, hypertension and arteriosclerosis. Some mushrooms, including Phellinus linteus, commonly produce a bundle of yellow antioxidant pigments that are composed of hispidin derivatives and polyphenols. Hispidin, metabolite of Phellinus linteus, is a potent antioxidant and inhibitor of protein kinase C (PKC). In this study, it was investigated whether hispidin would protect MIN6N pancreatic β-cells from oxidative stress by hydrogen peroxide. Treatment of MIN6N β-cells with 0.5mM hydrogen peroxide for 4 hours could cause a significant cell viability loss and an increase in apoptotic cells. Pre-treatment of MIN6N β-cells with hispidin for 24 hours reduced cell viability loss and decrease in apoptotic cells. In addition, 70μM hispidin significantly scavenged the intracellular ROS and inhibited apoptosis induced by hydrogen peroxide. In addition, the generation of thiobarbituric acid reactive substance (TBARS) was inhibited in the presence of hispidin in a dose-dependent manner. Also, 70μM hispidin significantly increased insulin secretion. These results suggested that hispidin might reduce oxidative stress damage of MIN6N β-cells by hydrogen peroxide. Hispidin may be effective in preventing MIN6N β-cells from the toxic action of reactive oxygen species in diabetes.

Due to the exhaustion of fossil fuel and the elevation of carbon dioxide concentration, and following the ‘Low Carbon, Green Growth’ strategy as Korea’s future vision, we need to find another energy source that can be substitute fossil fuel. One of the best potential bioenergy production source is microalgae. Microalgae are not only able to fixation carbon dioxide from combustion of fossil fuel but also able to convert carbon dioxide into energy intensive fuel molecules. Objectives of this study is to enhance the lipid contents of Chlorella sp. and to select the media for optimization of high production of lipid in Chlorella sp.. In order to get characteristics of Chlorella sp. MB01, do experiment characterization of Chlorella sp. MB01. Two strains used this experiment, Chlorella sp. MB01 and Chlorella sp. MB02. The experiment used five media that is BBM, BG11, CHU13, N8, and Watanabe. All experimental sets were cultivated under 5% CO2 balanced 95% air and under 100 μE/m2/s-1 of light intensity. The results were Chlorella sp. show higher growth when cultivate BG11. But the BG11 media contains C-source that is not economical media for crude biodiesel production. Chlorella sp. Shows higher growth cultivated N8 and Watanabe that do not contain another C-source. The Watanabe media show higher unsaturated lipid composition ratio than N8 media, the N8 media is much higher growth than Watanabe.

The aim of the study was the optimization of harvesting method for concentrating microalgae from microalgae mass culture. It is well known that the mass density of microalgae is usually very low and it is not economic to concentrate for the purpose of biodiesel production. To find out an efficient method for microalgae harvest, centrifugation, chemical flocculation, and sedimentation method was tested extensively. For chemical flocculation test, aluminum sulfate, ferrous sulfate, ferric chloride, starch, chitosan etc. were used which illustrated the aluminum sulfate is the most efficient flocculatant. As sedimentation media, various sizes of sand was tested.

Mussel adhesive proteins (MAPs) have been regarded as outstanding marine-derived biomaterials due to their biocompatibility, biodegradability, and adhesion ability to various surfaces. In order for MAP to crosslink and adsorb quickly in the tough sea environment, tyrosine residues of MAP are modified into 3,4-dihydroxyphenyl-L-alanines (L-DOPAs) by natural mechanism. In our previous research, fp-151, a recombinant MAP, was successfully over-expressed as a form of inclusion body in Escherichia coli. However, in vitro tyrosine modification was demanded after production for higher adhesion characteristic of fp-151. Instead of performing this additional treatment, in the present work, E. coli co-expression system of tyrosinase and fp-151 was constructed to modify tyrosine residues in vivo. In this method, fp-151 was over-expressed and mainly obtained not from inclusion body, but from soluble fraction. Furthermore, MALDI-MS/MS analysis of solubleexpressed fp-151 implies some of tyrosine residues were definitely modified. This study suggested one possible strategy for in vivo incorporation of modified tyrosine residues in MAPs. The approach is applicable for economic and efficient modification of tyrosine residues. Yoon Jeong YANG, Dooyup JUNG, Yoo Seong CHOI and Hyung Joon CHA* Department of Chemical Engineering, Pohang University of Science and Technology, Pohang, 790-784, Korea. PMB03 Comparison of Lipid Contents of Chlorella sp. MB01 and Chlorella sp. MB02 Cultivated in Various Media

Nowadays, we need renewable clean energy that can replace fossil fuels. Microalgae are favorable biofuel sources because of the potential high oil content and fast generation of the biomass. The objective of this study is to optimize lipid production and productivity in Coccomyxa sp. C-169 under various culture condition using statical method such as Fractional Factorial Design (FFD) and Central Composite Design (CCD). They are powerful tools to optimize the culture conditions and improve productivity of various algal cultures. Therefore, we carried out FFD firstly, using medium N8 in order to investigate the effects of each component in medium on lipid production in Coccomyxa sp. C-169.

Cyanobacteria are called as "Cell factory"1) which can produce a wide variety of metabolic compounds. Moreover they are the photosynthetic prokaryote on the earth to release oxygen into the atmosphere with photosystems I and II. Glucose-tolerance Synechocystis sp. PCC 6803 can use organic carbon and inorganic carbon. For analysis of their metabolic network, we constructed the central metabolism based on genome annotation2). With this in silico model, metabolic flux of the model was calculated using flux balance analysis according to its cultivation with various carbon sources and evaluated by fermentation data. Under photoautotrophic culture conditions, fluxes of TCA cycle were distributed similarly with anaerobic E.coli culture. These results were consistent w ith the previous report by Pierce et al in 19673). It showed under phototrophic culture Synechocystis utilized two biosynthetic pathway to generate Succinyl-CoA and 2-oxoglutarate instead of production of energy. However, in the case of heterotrophic culture, they produced energy using glyoxylate cycle. These results demonstrated how the network of central metabolism in cyanobacteria was working under various trophic culture.

Agar is extracted from red seaweeds and it is an important gelifying agent for biochemical use especially in the food industry. The enzymatic breakdown of agar can be performed by two types of agarases. Neoagaro-oligosaccharides produced by β-agarase inhibit the growth of bacteria, slow down the rate of degradation of starch, and are used as low-calorie additives to improve food quality. Therefore the development of the agarolytic complex capable of more effective agar hydrolysis ability is required to bring about a dramatic reduction of production costs. In this study, we expressed recombinant scaffolding protein mini-CbpA from Clostridium cellulovorans. To assemble the agarolytic complex via cohesin-dockerin interaction, we constructed a chimeric agarase cAgaB from Zobellia galactonovorans containing the catalytic domain of AgaB fused with a tandem-aligned dockerin domain of C. cellulovorans EngB. The resulting hydrolysis complex could degrade agar efficiently with synergic effect of agar-degrading enzyme activities. This is the first report on the formation of agarolytic complex using the cohesin-dockerin interaction system. The enhancement of agar-degrading complex activities will lead to the commercial production of useful products from agar biomass at low costs.

Researches on lactic acid fermentation of abundant sugars such as D-glucose, D-galactose, D-xylose and D-mannose have been carried out intensively. On the other hand, information on lactic acid fermentation of rare sugars is very limited. In this study, we investigated lactic acid fermentation of rare sugars by using Lactobacillus strains. Lactobacillus strains employed in this experiments were L. rhamnosus, L. casei, L. brevis, L. collinoides, L. diolivorans, L. salivarius and L. plantarum. Rare sugars used in this experiments were L-rhamnose, L-arbinose, L-fucose, D-mannitol, D-glucuronate, D-glucuronolactone, D-gluconate and D-glucarate. We identified different patterns of lactic acid fermentation between rare sugars and abundant sugars by using Lactobacillus strains This study may provide a way to the effective conversion of biomass containing rare sugars to lactic acid.

Microalgae are photosynthetic organisms to produce industrially important metabolites such as astaxanthin, beta-carotene, unsaturated fatty acid and etc. In this study, microarray analyses were used to obtain expression profiles of transcriptomes in the green alga Haematococcus lacustris at sequential time points during astaxanthin accumulation. Transcriptomes of Haematococcus lacustris was analyzed by a cDNA microarray with previously represented 972 expressed sequence tag. The gene expression results indicated that 268 genes exhibited differential expression by more than twofold. In these genes, 166 genes are up-regulated and the rest genes are down-regulated. Through this data, we found candidate gene expression that related production of astaxanthin at the sequential time point.

The aquatic toxicity assessment of TD53, a new algicidal compound, was performed by acute toxicity using a phytoplankton, a crustacean, and a young fish.Three aquatic organisms employed in this experiment: Skeletonema Costatum as a phytoplankton that is basic producer of marine ecosystem, and Daphnia magna as a crustacean that was used for the testing of chemicals according to OECD guidelines, and Paralichthys olivaceus as a young fish that is secondary consumer. As a result of the exposure experiments, EC50 value of TD53 to Skeletonema Costatum showed 1.21 μM when exposed for 96 hrs, and the EC50 value in Daphnia magna was 0.62 μM for 48 hrs exposure, and the LC50 value of Paralichthys olivaceus was 2.48 μM for 72 hrs. On the other hand, solutol used as a dispersion material to elevate solubility of TD53 showed no considerable toxicity in the range of concentration used in the experiment of TD53.From the results above, Daphnia magna was most sensitive to TD53 among the three organisms than other aquatic organisms. Based on that results, NOEC (No Observed Effect Concentration) for TD53 was calculated to be 0.25 μM, and PNEC (Predicted No Effect Concentration) by employing factor value of 100 was concluded to be 6.2 nM.

Alginate degrading bacteria were isolated from pickled hairtail guts from Mokpo, Korea. PolyM-specific lyase from tenotrophomonas maltophilia KS2010 was cloned into pColdI vector and overexpressed in E. coli. Molecular weight of new alginate lyase was deduced as 36.6 kDa and pI was calculated to 6.5. The alginate lyase was overexpressed as a his-tag fusion protein. A novel alginate lyase inhibited the growth of biofilm forming bacteria, Pseudomonas aeruginosa. Strain KS2010 grew well on minimal agar plate or minimal liquid medium containing alginate as a sole carbon source. Acknowledgement : This work was supported by New &Renewable Energy R&D program(20093020090020) under the Korea Ministry of Knowledge Economy(MKE)

To develop prodigiosin as biological control agent against Chattonella antiqua, a harmful alga that can cause red tides, selection of an organic solvent for prodigiosin extraction from culture broth was performed. Prodigiosin was extracted using nine solvents (hexane, toluene, chloroform, ethyl acetate, ethanol, methanol, acetone, acetonitrile, and seawater), and extracts were analyzed by LC-MS. As a result, acetone was regarded as an optimal organic solvent for the extraction of prodigiosin from culture broth. The amount of prodigiosin extracted with acetone was almost the same as that extracted with ethanol. Moreover, the processing time could be reduced by using acetone because it has a lower boiling point than ethanol. Considering these results, we think that acetone was a very useful extraction agent for the extraction of prodigiosin as a biological control agent. (PE10050 and PN07020).]

Alginate degrading bacteria were isolated from pickled hairtail guts from Mokpo, Korea. Sequence determination and phylogenetic analysis of 16S rRNA genes showed that alginate degrading bacteria were Corynebacterium sp, Brevibacterium sp, Sphingomonas sp, Methylobacterium sp, Streptomyces sp, Micrococcus sp, Krebsiella sp. and Stenotrophomonas sp. Putative alginate lyase from Stenotrophomonas sp. was cloned into pColdI vector and overexpressed in E. coli. Molecular weight of new alginate lyase was deduced as 82 kDa and pI was calculated to 6.87. The alginate lyase was overexpressed as full sequence of gene and active form without signal peptide sequence. Mutation with five amino acid residue showed higher alginate degrading activity. Acknowledgement : This work was financially supported by the Ministry of Knowledge Economy(MKE) and Korea Industrial Technology Foundation (KOTEF) through the Human Resource Training Project for Strategic Technology.

We used macroalgae (Hizikia fusiformis, Laminaria, and Undaria pinnatitida) to adsorb heavy metal ions. For pH from 2 to 8 adsorption of chromium reached a maximum at pH 4, and then decreased at higher pH as determined by Atomic Absorption Spectrometer. At the same conditions adsorption of copper was kept increasing up to pH 8. This behavior was different from lead, cadmium, and manganese, for which adsorption increased up to pH 4, and then did not change significantly at higher pH up to 8. We compared adsorption of heavy metal ions in solutions containing single metal ion and five metal ions (lead, cadmium, manganese, chromium, and copper). In the case of chromium the presence of other metal ions improved the adsorption of chromium ion. However, presence of other metal ions decreased the adsorption of copper ion suggesting that we may be able to enhance the adsorption by adding or eliminating other ions in the solutions.

The aquatic toxicity assessment of TD49, a new algicidal compound, was performed by acute toxicity using a phytoplankton, a crustacean, and a young fish.Three aquatic organisms employed in this experiment: Skeletonema Costatum as a phytoplankton that is basic producer of marine ecosystem, and Daphnia magna as a crustacean that was used for the testing of chemicals according to OECD guidelines, and Paralichthys olivaceus as a young fish that is secondary consumer. As a result of the exposure experiments, EC50 value of TD49 to Skeletonema Costatum showed the ranging from 0.33 to 0.36 μM when exposed for 96 hrs, and the EC50 value in Daphnia magna was 0.62 μM for 48 hrs exposure, and the LC50 value of Paralichthys olivaceus was 0.58 μM for 72 hrs. On the other hand, solutol used as a dispersion material to elevate solubility of TD49 showed no considerable toxicity in the range of concentration used in the experiment of TD49.From the results above, Skeletonema costatum was most sensitive to TD49 among the three organisms than other aquatic organisms. Based on that results, NOEC (No Observed Effect Concentration) for TD49 was calculated to be 0.20 μM, and PNEC (Predicted No Effect Concentration) by employing factor value of 100 was concluded to be 3.3 nM.

Several agar-degrading bacteria were isolated from gut of spiny turban shells. These bacteria were examined by Lugol’s iodine and identified as extracellular agarase-producing bacteria. Among them, one species made clear depressions around colonies. Agar-degrading ability of this bacterium was examined by measuring viscosity-change of the inoculated medium. The viscosity of the inoculated medium was decreased by more than 60% after 20 hour-cultivation while pure medium did not show any decline of viscosity. The sequence of 16s rRNA of the bacterium was analyzed and a comparative analysis of the 16s rRNA sequence was performed by BLASTN with Genebank data base. The result indicated that it might be one species of the genus, Pseudoalteromonas. In addition, a homology-comparison-study of relative strains was performed, and as a result, the bacterium was identified as one of Pseudoalteromonas nigrifaciens strains. Experiments, such as assay of enzyme activity, enzyme identification are being performed for further study.

Growing concerns over the environmental impact of fossil fuels and their inevitable depletion have led to intense research on the development of alternative energy or chemicals. One of alternatives is biomass including foods, plants, and wastes. It can beconverted into biofuel or other chemicals through saccharification and fermentation process. Conventional raw material for fermentation is terrestrial resources such as corn, sugarcane, and wood. Compared to other feedstocks, macroalgae have a great potential for cultivation area. Ulva pertusa, dominant species in Korea, is distributed in various coastal waters including the brackish waters of the inner bays. Also, Ulva pertusa is rich in polysaccharide 44.7 % of dry weight. Therefore, it is worthwhile to determine how to make use of Ulva pertusa in an economic manner. In this study, we investigated the optimal saccharification condition of Ulva pertusa by changing reaction temperature, acid concentration, and reaction time.

The removal efficiency of cadmium and manganese was studied by three species of Korean seaweeds (Hizikia fusiformis, Laminaria and Undaria pinnatitida). The best removal efficiencies were 88% for cadmium using Hizikia fusiformis and 57% for manganese using Laminaria. The adsorption data could fit well the Langmuir adsorption isotherm.

In order to make the best choice for CO2 abatement using renewable energy technologies, it is important to be able to adapt these technologies on the basis of their sustainability, which may include a variety of environmental indicators. This study examined the comparative sustainability of renewable technologies in terms of their life cycle CO2 emissions and embodied energy, using life cycle analysis. The models developed were based on case studies of bioenergy pilot plant in Pocheonsi of nothern Kyungki province. The comparative results showed that power generation of biogas was associated with 0.96 kWh/m3biogas and the reduction of CO2 emission was 2.1kg of CO2 /kgBiomass, other environmental indicator using wood pellet was -0.717kg of CO2 /kgBiomass. These indicators applied to gain a complete picture of the technologies studied in the regional area. Final results were total emission of CO2 in Pocheonsi is 448,210 tCO2, around 399,877 tCO2 for electricity and for heat generation, and 47,450 tCO2 for transportation. When used 1,984 m3/day of waste (pig manure etc.) and operated CHP with wood pellet of 220,000 m3/year, the CO2 emission in Pocheonsi was left as is an emission of 230,070 tCO2 and an abatement of CO2 in this region was increased by 49.9%.

Due to the negative impacts of global warming and potential depletion of petroleum, the research for alternative fuels is an emerging issue all over the world. Biodiesel derived from biomass such as animal fat and vegetable oil is a potential substitute for petroleum-based diesel. Especially, microalgae have been paid much attention as biomass feedstock for biodiesel production because they have high growth rate and need low land-use compared with conventional biomass. And they can fix CO2 directly from exhaust gas of industrial facilities.Recently, microalgal cultivation in various temperatures to produce biodiesel has been studied and temperature had an effect on microalgal growth rate and lipid contents.In this study, Nannochloris oculata has been cultivated in batch-type photobioreactor (PBR) to fix CO2 and produce biodiesel. Optimum microalgal culture conditions such as CO2 concentration, flow rate were investigated for high growth rate. Based on optimum culture conditions, column-type PBR with water jacket of which temperature can be controlled was developed and lipid productivity and component were investigated in PBR under alternating temperatures.

For achieving biodiesel production from microalgae, high density cultivation of microalgae is the most important step through the whole process. So, economical cultivation technology of microalgae should be developed.Photosynthetic mechanism consists of light reaction and dark reaction. In light reaction, light energy is converted into chemical energy in the form of the energy-carriers ATP and NADPH and in dark reaction, CO2 and water are converted into organic compounds. Because dark reaction is considered as an overall rate-determining step in photosynthesis, it doesn’t need to illuminate photobioreactor (PBR) continuously by artificial light source. High microalgal growth rate can be achieved economically by development of PBR with periodic light having optimum duty cycle, not continuous light.In this study, optimum microalgal culture conditions in bubble column type PBR such as CO2 concentration, flow rate and medium were investigated. Based on optimum culture conditions, periodic light supply PBR of which duty cycle can be controlled in minutes or seconds was developed and microalgal productivity and celluar component by various duty cycles of periodic light were investigated.

Lignin hydrolysates are a potential source of sugar for the renewable production of biofuels by fermentative bacterial strains. However, when the lignin-cellulose is hydrolyzed, many phenolic acids and aldehydes are produced, including coumaric acid, ferulic acid and vanillin. Microarray results obtained with a culture of E. coli exposed to ferulic acid found that several gene clusters were strongly induced, including the marA regulon and the aaeXAB operon. Using these findings, the promoters from several genes included in the marA regulon were cloned upstream of the luxCDABE genes within plasmid pDEW201, allowing us to monitor the expression levels of each gene through the bioluminescent output. Two strains were used to monitor for the presence of the hydrolysate compounds, ZWF, which has the zwf promoter fused with the lux operon, and SP4, which has the inaA promoter fused with the lux operon. Tests with ferulic acid found strain SP4 to be more responsive, with a greater induction level than ZWF. These results are in agreement with the microarray data which showed the inaA gene was induced by ferulic acid while zwf showed no significant change. Another interesting finding of this study was the stronger induction of the inaA promoter, i.e., strain SP4, by the acid forms of the test compounds when compared with the aldehyde forms. For instance, when SP4 was exposed to the 1g/L of vanillic acid or vanillin, the acid resulted in a 30-fold induction while the aldehyde gave only a 5-fold induction. Finally, a comparison between several phenolic acids showed that strain SP4 responded differentially to non-native compounds. In other words, a test with 1 g/L 4-hydrobenzoic acid, a phenolic acid produced naturally by E. coli, resulted in only a 3-fold induction while both vanillic and ferulic acid led to a 30-fold induction when added at the same concentration. In this study it was demonstrated that strain SP4 “responds” to compounds present within hydrolysates and that this strain shows a preferential response for phenolic acids not naturally produced by E. coli. These results clearly show the potential of this strain as a biosensor to monitor the characteristics of the wood hydrolysate and to evaluate the possible inhibition of fermentative bacterial strains by the phenolics present in the hydrolysate.