Earticle

b-glucans are structural cell wall polymers of many microorganisms which possess several dunctionality including antioxidant activity and immunomodulatory properties. In the previous study, the low molecular weight b-glucans degraded by gamma irradiation showed higher antioxidant. In this study, it has been carried out to evaluate the immune-enhancing activities of low molecular weight b-glucan degraded by gamma irradiation. The results showed that RAW264.7 macrophage cell stimulation activities of low molecular weight b-glucan were higher than that of high molecular b-glucan. In addition, the oral administration of low molecular weight b-glucan significantly increased the proliferation and cytokine (IFN-ɤ and IL-2) release of spleen and Peyer’s patch cells compared with high molecular weight b-glucan.

Although glutamic acid is a non-essential amino acid, glutamate is an important neurotransmitter that plays a key role in long-term potentiation and is important for learning and memory.We analyzed the glutamate contents of methanolic extracts from 14 species medicinal herbs; Angelica gigas, Polygala tenuifolia, Cnidium officinale, Polygonum multiflorum, Phaseolus radiates, Poria cocos, Schizandra chinensis, Thuja orientalis, Eleutherococcus senticosus, Acorus gramineus, Hovenia dulcis, Codonopsis lanceolata, Zingiber officinale, Coptis japonica. We adopt HPLC system with FDAA (Marfey’s reagent) using reversed C18 column, which is available for the detection of chiral form of L, and D-glutamate. Our results show that Thuja orientalis, Schisandra chinensis, Hovenia dulcis, and Coptis japonica extracts exhibited relatively high glutamate contents of 34.92, 18.77, 22.42, and 28.23 μg/mg, respectively. Our data also exhibit that there are no detectable D-glutamate among 14 medicinal herbs. Our results indicate that these medicinal herbs could be useful functional resources of L-glutamate, which maybe lead to improve memory and learning ability.

Calcium is a key mineral that affects especially the quality of life as human age. The bioavailability of calcium is currently one of the most important topics in nutrition research and is correlated with gastrointestinal solubility. We applied the poly-γ-glutamic acid, an edible and biodegradable polymer, in order to increase the solubility of calcium. The result showed that γ-PGA enhanced calcium absorption from the small intestine when administered to rat. In vitro, the solubility of calcium was increased in a dose- and molecular weight-dependant manner. And we confirmed the effect of PGA on the calcium uptake in the small intestine using rats as an animal model system. γ-PGA had been approved as functional food ingredient by Korean Food and Drug Administration (KFDA); its health claim is “the promotion of calcium absorption”. Useful dosage for calcium absorption is suggested to 60~70 mg per day. These studies may suggest more effective applications of calcium supply as the dietary supplements. [This work was supported by a grant from the Next-Generation BioGreen 21 Program (No. PJ0083272011)]

In this study, gamma irradiation sensitivities of bacteria and viruses in porcine skin were evaluated to develop the dressing material and a xenoskin graft. Escherichia coli and Bacillus subtilis were used as model pathogens and inoculated at 106 - 107 log CFU/g. As model viruses, porcine parvovirus (PPV), bovine viral diarrhea virus (BVDV), and poliovirus were used and inoculated at 105-- 106 TCID50/g into porcine skin. The D10 value of E. coli was found to be 0.25±0.1 kGy. B. subtilis endospores produced under stressful environmental conditions showed lower radiation sensitivity as D10 was 3.88±0.3 kGy in porcine skin. The D10 values of PPV, BVDV, and poliovirus were found to be 1.73±0.2, 3.81±0.2 and 6.88±0.3 kGy, respectively. These results can offer the basic information required for inactivating pathogens by gamma irradiation and achieving dressing material and porcine skin grafts

The extraction conditions of piceid from grape fruit stem (GFS) was optimized with regard to extraction method, extraction solvent, reaction temperature, solvent concentration and extraction time. The content of piceid in hot water extraction was measured as 76.5 ㎎/100g. The supercritical fluid extraction was carried out at a temperature of 40℃, with static extraction period of 15 min and dynamic extraction time 30 min, using ethanol as a modifier at 1.5 ml/min flow rate. The content of piceid in supercritical fluid extraction was measured as 1.4 mg/100g at a operation pressure of 300 bar. The ultra-sonication with frequency of 42 kHz was applied to the hot water extraction at temperatures of 25℃, 40℃, 60℃, respectively. The piceid contents in case of ultra-sonication aided extraction were 18.1-33.8 mg/100g, depending on the extraction temperature. Consequently it was confirmed that the hot water extraction process gave the highest yield of piceid from GFS.

Poly-γ-glutamic acid (γ-PGA) is a major adhesive component of fermented soybeans. γ-PGA is an edible and biodegradable polymer with repeated-chain structure of glutamate, an amino acid. We analyzed in vitro and in vivo the immune response activity of high molecular weight γ-PGA from Bacillus subtilis (chungkookjang), γ-PGA was orally administered to C57BL/6 mice, and immune response activity was examined by monitoring of natural killer (NK) cell- mediated cytotoxicity and interferon-γ (IFN-γ) secretion from splenocytes. The results revealed that the levels of NK-cell mediated cytotoxicity and IFN-γ secretion in mice treated with high molecular weight γ-PGA were higher than those treated with lower molecular weight γ-PGA. We also carried out a single-center, randomized, double-blind, placebo-controlled clinical trial for evaluating the effect of human immunity after 8-week administration of γ-PGA in healthy volunteers. The study resulted in a tendency to increase the NK-cell mediated cytotoxicity, and also the elevated expressions of CD8, CD56 were observed in γ-PGA administrated group. This clinical study is an important result in establishing the effect of γ-PGA on immune stimulating function. [This work was supported by the Leading Industry Development for Economic Region of the Chungcheong Leading Industry Office(CCLIO), Korea Institute for Advancement of Technology(KIAT) and Ministry of Knowledge Economy(MKE).

In this study, antioxidant activity of crude extracts from Zosteria asiatica was investigated. The collected samples of Z. aisatica were extracted twice with acetone-CH2Cl2(1:1) and MeOH, respectively and then combined crude extract of Z. asiatica was partitioned between H2O and CH2Cl2. The aqueous layer was fractionated with n-buthanol and H2O and then the organic layer, with 85%aq. MeOH and n-hexane. The antioxidant activities of crude extract and its solvent fractions were evaluated by using DPPH radical, authentic ONOO-, and ONOOgenerated from SIN-1(3-morpholinsydnonimine) in vitro. n-BuOH and 85% aq. MeOH fraction showed potent scavenging effects on DPPH radical, authentic ONOO-, and ONOO- from SIN-1. On the other hand, all tested samples exhibited protective effect on oxidative damage of purified genomic DNA, compared with control.

Arctic yeast Leucosporidium sp. produces a glycosylated ice-binding protein (LeIBP) with a molecular mass of approximately 25 kDa, which can lower the freezing point below the melting point once it binds to ice. LeIBP is a member of a large class of ice-binding proteins, the structures of which are unknown. Here, we report the crystal structures of non-glycosylated LeIBP and glycosylated LeIBP at 1.57 Å and 2.43 Å resolution, respectively. Structural analysis of the LeIBPs revealed a dimeric right-handed β-helix fold, which is composed of three parts: a large coiled structural domain, a long helix region (residues 96–115 form a long α-helix that packs along one face of the β-helix) and a C-terminal hydrophobic loop region (243- PFVPAPEVV-251). Unexpectedly, the C-terminal hydrophobic loop region has an extended conformation pointing away from the body of the coiled structural domain and forms intertwined dimer interactions. In addition, structural analysis of glycosylated LeIBP with sugar moieties attached to Asn185 provides a basis for interpreting previous biochemical analyses as well as the increased stability and secretion of glycosylated LeIBP. We also determined that the aligned Thr/Ser/Ala residues are critical for ice binding within the B face of LeIBP using site-directed mutagenesis. Although LeIBP has a common β-helical fold similar to that of canonical hyperactive antifreeze proteins, the ice-binding site is more complex and does not have a simple ice-binding motif. In conclusion, we could identify the ice-binding site of LeIBP and discuss differences in the ice-binding modes compared to other known AFPs and IBPs.

The Ice binding protein (IBP) is a prerequisite material for organism to be allowed to live in a subzero environment. Ice growth in a cold environment is fatal for organism which is not just physically destruction of inner cell organelle but also chemical damage such an osmotic shock. IBP has been characterized property of which ability inhibit the ice growth by binding to specific ice plane. Flavobacterium frigoris isolated from Antarctic area produce an ice-binding protein (FfIBP) to survive and reduce damage from ice growth. The FfIBP has been cloned and over-expressed in Escherichia coli. To diagnose ice-binding mechanism, we measured thermal hysteresis (TH) activity which is numerical value of a gap between freezing and melting point as well as ice re-crystallization inhibition activity. Thermal hysteresis activity of the FfIBP was approximately 2.5℃ at 50 uM that is 10 times higher than moderately active LeIBP. Furthermore, the Ice Re-crystallization inhibition activity represent the FfIBP has ability to inhibit ice growing at low concentration 2.5 uM limit. Consequently the FfIBP was classified as a hyper-active Ice binding protein. Also, preliminary X-ray crystallography was performed to reveal the ice-binding site of FfIBP at the molecular level.

A marine microalgae Aurantiochytrium limacinum SR21 is known to accumulate significant amounts of omega-3 fatty acids, which are very important for the health of humans and in animal nutrition. A statistical technique was applied to investigate the effects of several culture conditions on growth and fatty acid accumulation of A. limacinum SR21, and the results showed that the initial culture pH was the one of the significant factors. It was observed that this strain grew well at low initial pH and the culture pH was naturally increased over 8 in shake flask culture. We also examined the growth behavior and pH profile under different pH conditions in batch bioreactor cultures.

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 and a test to determine the stability of prodigiosin were performed. Prodigiosin was extracted using nine solvents, and extracts were analyzed by LC-MS. Acetone was selected as the best organic solvent because of its high extraction efficiency and less process time. Stability tests for progidiosin were performed at various temperatures, and algicidal activity against C. antiqua was also tested. Ultimately, more than 98% stability was sustained after 30 days at 4℃, and less than 30% stability was maintained after 30 days at 37℃. More than 5~14% of the algicidal activity of prodigiosin extracted with acetone was sustained at each temperature, when compared with the prodigiosin extracted with ethanol. Although prodigiosin was kept for 30 days in an optimum organic solvent, the stability of prodigiosin was safely maintained and algicidal activity was sustained at low temperatures such as 4℃. Considering these results, we know that acetone was a very useful extraction agent for the extraction of prodigiosin as a biological control agent.

Diatoms are single celled algae that make silica shells (frustules) with nanoscale features imbedded within two-dimensional pore arrays. Living diatom itself metabolically insert nano-structured titanium dioxide into its surface. Navicula sp. (#1271) form Korean culture bank (KMMCC) was cultured in natural sea water supplemented with f/2 nutrient s in the photo bioreactor .In stage I , diatom cells grown up on dissolved silicon until silicon starvation was achieved. In stage II , soluble titanium and silicon were continuously fed to the silicon starved cell suspension (105 cells /ml) for 10 hrs. The feeding rate of titanium was designed to circumvent the precipitation of titanate in the liquid medium, and feeding rate of silicon was designed to sustain one cell division .The addition of titanium to the culture had no detrimental effect on the cell growth and preserved the frustule morphology. Intact frustule was prepared from harvest and analyzed for titanium using SEM, TEM, EDS and XRD analysis.

A marine bacterium possessing alginate-degrading activity was isolated from brown seaweed soup liquefied by salted and fermented anchovy, previously. The bacterium was deginated to Sphingomonas sp. Strain MJ-3 based on 16S-23S ITS region sequences, biochemical characteristics and cellular fatty acid composition analysis. A novel alginate lyase gene was overexpressed in E. coli BL21 (DE3). The MJ-3 alginate lyase protein shared below 27.0% sequence identity with exolytic alginate lyase, A1-IV of Sphingomonas sp. A1. The time-dependent degradation of alginate by MJ-3 alginate lyase was analyzed by by high-field 1H nuclear magnetic resonance (NMR) spectroscopy, using an ECX-NMR 400Hz JEOL spectrometer (JEOL, USA). Based on the results of FPLC, TLC and NMR, the recombinant MJ-3 alginate lyase is determined to be an exolytic alginate lyase that can degrade the alginate into alginate monosaccharides. Acknowledgement : This work was supported by New & Renewable Energy R&D program(20093020090020) and Korea Institute for Advancement in Technology (KIAT) through the Workforce Development Program in Strategic Technology under the Korea Ministry of Knowledge Economy(MKE).

Heteropolysaccharide-7 (PS-7) is a possible alternative to xanthan or gellan due to its properties and potential applications. Sucrose was developed as a carbon source for production of PS-7 by Beijerinckia indica HS-2001 to overcome catabolite repression against glucose. The optimal carbon source and inoculum size for the production of PS-7 by B. indica HS-2001 were found to be sucrose and 5.0% (v/v). The optimal agitation speed and aeration rate for cell growth of B. indica HS-2001 were 495 rpm and 1.8 vvm using response surface methodology (RSM), whereas those for the production of PS-7 were 440 rpm and 1.2 vvm. The optimal inner pressure for cell growth of B. indica HS-2001 in a 100 L bioreactor was 0.02 MPa, whereas that for the production of PS-7 was 0.04 MPa. The production of PS-7 by B. indica HS-2001 from 30.0 g/L sucrose with an optimized inner pressure was 10.20 g/L, which was 1.32 times higher than that without inner pressure in a 100 L bioreactor. The maximal production of PS-7 under optimal conditions was 1.55 times higher than that before optimization.

A microorganism producing carboxymethylcellulase (CMCase) was isolated from seawater, identified as Bacillus velezensis by analyses of 16S rDNA and partial sequences of the gyrA, and designated as B. velezensis A-68. The optimal conditions for production of CMCase by B. velezensis A-68 were established using response surface methodology (RSM). The optimal concentrations of rice hulls and yeast extract, and initial pH of the medium for cell growth were 60.2 g/L, 7.38 g/L, and 7.18, respectively, whereas those for production of CMCase were 50.0 g/L, 5.00 g/L, and 7.30. The analysis of variance (ANOVA) implied that the most significant factor for cell growth as well as production of CMCase was yeast extract. The optimal concentrations of K2HPO4, NaCl, MgSO4·7H2O, and (NH4)2SO4 in the medium for cell growth were 7.50, 1.00, 0.10, and 0.80 g/L, respectively, which were the same as those for production of CMCase. The ANOVA also indicated that highly significant (“probe>F” less than 0.0001) for cell growth was K2HPO4, whereas those for production of CMCase were K2HPO4, MgSO4·7H2O, and (NH4)2SO4. The optimal temperatures for cell growth and production of CMCase were 30 and 35℃, respectively. The maximal production of CMCase under optimized conditions was 83.8 U/mL, which was 3.3 times higher than that before optimization. In this study, rice hulls were developed as a substrate for production of CMCase and time for production of CMCase was reduced to 3 days using a newly isolated marine bacterium.

Harvesting of marine algae, Dunaliella tertiolecta, was studied to optimize Dissolved air flotation(DAF) method for dewatering microalge 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 optimal condition for microalgae harvesting by DAF, various chemical flocculants, such as organic flocculants (e.g.,poly aluminium chloride, aluminium sulfate, aluminium potassium sulfate, ferrous sulfate, sodium carbonate, and sodium aluminate), inorganic flocculant (e.g., polyacrylamide), biopolymer flocculants (e.g., chitosan and starch) were tested. Among the tested DAF, poly aluminium chloride and aluminium sulfate, showed best performance.

It is of immense importance to develop carbon-neutral or even carboncapturing technologies that may mitigate the dynamics of the climatic implications of rising anthropogenic CO2 emissions. Today, photosynthesis also promises production of third-generation biofuels that may assist in recycling atmospheric CO2. The present study aim is effect of dissolved CO2 concentration on the growth of two microalgal strains. First, studies dCO2 concentration in different CO2 concentration. That 2.5%, 5%, 10% CO2 in air and air was supplied at the reactor at a flow rate of 0.1 vvm and 0.05 vvm . Secondly, microalgae cultivate at the first experiment culture condition. First experiment result compare experimental result value and equation value these are similar. Using Henry’s law, the mass transfer rate between the bubble and the liquid phase can be calculated equation. Second experiment result is very similar of fresh cell weight(FCW) and NO3 at same group in reactor supplemented with same amount of CO2 per hour. Future work will be cultured at L:D cycle and using another strain.

Cultivation of microalgae provides an opportunity to solve the risk of fossil fuel utilization. The growth of microalgae is affected by various environmental factors such as light energy, pH, CO2, and nutrient supply. Among these factors, CO2 is the only carbon source for the growth of microalgae and serves for photosynthetic cell culture. Effectively delivery of CO2 is important for the culture of microalgae. Dunaliella tertiolecta is a marine green flagellate and fast growing alga. In this study focused on effect of carbon dioxide on microalgae, Dunaliella tertiolecta. Dunaliella tertiolecta UTEX LB 999 was cultivated at various CO2 concentrations and flow rates. The carbon dioxide concentrations were air, 0.3, 0.5, 1, 2, and 5%. The flow rates were 100, 200, 400, and 600cm³/min. The results indicated that CO2 concentrations more affected than flow rates for the growth of D. tertiolecta. The CO2 supplied to the photobioreactor affected the pH of the medium. The pH values were 7.80, 7.5, and 6.27, respectively, at air, 0.3, and 5% CO2 concentrations. Growth rates of D. tertiolecta increased with increasing concentration of CO2 and they are higher than without CO2 supplementation.

Microalgae are prokaryotic or eukaryotic photosynthetic microorganisms that can grow rapidly and live in harsh conditions due to their unicellular or simple multicellular structure. Microalgae can produce wide variety of valuable compounds which include the antioxidants, polyunsaturated fatty acids, oil, natural dyes and other fine chemicals and biomasses. Coccomyxa sp. C-169 is one of the microalgal species which live in freshwater. Whole genome sequence of Coccomyxa sp. C-169 has already been published by JGI and it can be applied to strain improvements to produce the valuable compounds. These experiments were carried out in order to investigate significant factors for enhancement of biomass production. In this experiment, we applied the FFD (Fractional Factorial Design) methods to N8 medium components to analyze the major factors that influence on cell growth. We choose the four factors from N8 medium (KNO3, KH2PO4 & Na2HPO4, MgSO4․7H2O, CaCl2․ 2H2O) and these four factors has divided into two levels with the eight experimental groups include the two centeral points. Experimental design has designed with MINITAB software and result of experiments was calculated using MINITAB software according to its compositions of medium and fermentation data.

Microalgae have received considerable attention because of its ability to produce not only bioenergy but also high value added pharmaceuticals, fine chemicals and health foods. The microalgal cultivation with high yield of biomass productivity is essential to produce economically microalgal production. The purpose of this work is to develop new photobioreactor and its operation method for microalgal cultivation. We made Circulated Tank Photobioreactor (CTPBR), the new tank type of photobioreactor with culture broth circulated and carbon dioxide supplied system for outdoor microalgal mass cultivation. Dunaliella sp. was maintained in suspension and carbon dioxide was supplied effectively in CTPBR. Dunaliella sp. grew at a rate of fresh cell mass 0.15g/L/day in CTPBR by sunlight autotrophic cultivation using sea water supplemented minimal nutrients other hand, the cell was not propagated in conventional tank photobioreactor that was not circulated and supplied carbon dioxide by conventional aeration method.

Carbonic anhydrase (CA, EC 4.2.1) prompt to uptake of CO2 from atmosphere into intracellular system in addition to the diffusion process during carbon fixation (John, 2011). In this study, we selected the α-CA3 among five different putative alpha-type carbonic anhydrase (α-CA) of Phaeodactylum tricornutum CCMP 632. First, we characterized amino acid sequence of putative α-CA3 by comparative study with other CAs which has similar sequence. For their molecular characterization, we carried out heterologous recombinant protein expression. Several vectors, expression conditions, and expression hosts were tried. As a result, soluble protein of α-CA3 was successfully obtained with pMAL-c2x vector and expression host of E. coli Origami2. Using maltose-binding protein (MBP), MBP:α-CA3 recombinant protein was purified by amylose-bead and eluted with maltose. Purified putative α-CA3 was used for measuring activity. Activity assay was investigated spectrometric and titmetric methods. This study was first characterization of α-type carbonic anhydrase in P. tricornutum, and can be used for carbon capturing and its application.

As the price of conventional fossil fuels continues to escalate, so-called alternative fuels have become more attractive. Lipids from marine microalgae can be transformed into biodiesel fuel, a renewable energy. Microalgae – either marine microalgae or fresh water microalgae – have received enormous interests as one of the most promising solution to the global warming and the depletion of fossil fuels. Recent reports revealed various detrimental effect of producing biofuels from crop (starch) biomass, as there would be a risk of greater food insecurity, higher food prices and shortage of land space. Dunaliella species belong to microalgae are known as massive lipid producers. Lipid extraction is an important process step to produce fuel cost effectively from microalgae. The purpose of this work was to optimize lipids extraction methods using solvent from Dunaliella sp.. We tested various factors (kinds of solvents, amount of solvents, extraction temperature and time) were analyzed and compared for the lipid extraction efficiency. The solvent mixture of methanol and chloroform extracted lipids the most effectively and unexpectedly methanol alone was fairly good lipid extraction system from Dunaliella sp..

Jeju island is a rich repository of natural resources escecially marine resources and we research the Jeju marine organisms and algae. We performed screening tests about 100 species marine algae be collected in Jeju island for examination of antioxidant and anti-inflammatory effects. One of them, Dictyopteris undulata, has good antioxidant and anti-inflammatory effects. This study focused on evaluation of the antioxidant and anti-inflammatory activity from D. undulata extracts. D. undulata was extracted using 80% ethanol and then fractionated sequentially with n-hexane, ethyl acetate, and butanol. To screen for antioxidant and anti-inflammatory agents effectively, we first examined the inhibitory effect of the D. undulata extracts on the production of oxidant stresses (DPPH, xanthine oxidase and superoxide). In addition, we examined the inhibitory effects of D. undulata on the production of pro-inflammatory factors (NO, PGE2, TNF-α, IL-6 and IL-β) in murine macrophage cell line RAW 264.7 activated with lipopolysaccharide (LPS). Of the sequential solvent fractions of D. undulata, ethylacetate fractions decreased production of oxidant stresses (DPPH and superoxide). For anti-inflammatory measurement, the ethylacetate fractions of D. undulata inhibited the production of pro- inflammatory factors. These results suggest that D. undulata has significant effects on oxidant stresses and pro-inflammatory factors and is a possible antioxidant and anti-inflammatory therapeutic algae.

Production of biomass from microalgal culture for biodiesel production, which cultured in ocean has many advantages : (1) Wave is used for natural mixing energy on micro algae suspension culture in photobioreacter.(2) Ocean is cheaper than land cost as microalgae culture area.(3) Seawater can provide constant temperature for microalgae culture. Sunlight is important factor for microalgal culture in ocean as photosynthesis. Ultraviolet (UV) of sunlight is harmful to viability of microalgae. The effect of UV cutoff was investigated using closed photobioreactor (PBR). The surface of the PBR was covered with UV cutoff film. The film can block 97% of UV in solar radiation. The PBR covered with UV cutoff film showed higher biomass productivity than the PBR without the film.

Microalgae are unicellular microorganisms, capable of performing photosynthesis and important for life on earth as a primary producer. In recent years, microalgae have been considered as feedstocks for alternative liquid biofuels of petroleum based fuels because of their high oil and biomass productivities1, 2. Microalgae ocean culture system has a lot of advantage such as culture temperature controlling by seawater temperature, natural mixing, natural light, and culture place provision. In this study, we performed microalgae seasonal (spring, summer and fall) cultivation utilizing floating plastic photobioreactors in the sea near Wando to confirm the potential of microalgae cultivation in the ocean. The highest biomass productivity was achieved in the summer by optimal seawater temperature (0.11 g L-1 d-1). However, the biomass productivities in spring and fall were 0.005 g L-1 d-1 and 0.02 g L-1 d-1, respectively, by low seawater temperature. As a result, we confirmed the possibility of microalgae cultivation in the ocean.

Recently, the beer industry utilizing mineral-rich bedrock water and malt barley (Hordeum vulgare, cv 'Baek Ho') is getting a lot of attention in Jeju island. This study focused on the usage of brew slurry which is left out after making beer, obtained from the pilot plant in Jeju Specia Self-Governing Province Development Corporation (JPDC). A 12-week feeding trial was conducted to investigate the effect of brewer's yeast (JBY) as a feed additive for juvenile olive flounder(Paralichthys olivaceus). The fish were fed four experimental dietary supplemented with 0% (control), JBY (1%, 3%, 5%) of BY mixed with basal diet. All the cases fed diets containing JBY (1%, 3%, 5%) of JBY revealed slightly higher survival rate than that of control experiment(0%). This study also compared their the glucose, cholesterol, glutamic oxaloacetic transaminase (GOT), and glutamic-pyruvic transaminase (GPT). The case of dietary 1% JBY was proven to be the optimal concentration in all parameters tested. The results of these experiments suggest that the brewer's yeast (JBY) can be a good candidate for dietary supplementation on the growth of juvenile olive flounder.

After conversion of CO2 to bicarbonate by carbonic anhydrase (CA) reversibly, Phosphoenolpyruvate carboxylase (PEPCase, EC4.1.1.31) catalyzes the irreversible reaction of PEP and HCO3- into four-carbon organic acid oxaoacetate (OAA) using Mg2+ as a cofactor. PEPCase also plays a significant role in anaplerosis by providing OAA and/or malate,　replenishing the tricarboxylic acid cycle (TCA) intermediates in all photosynthetic organisms and also in non-photosynthetic bacteria and protozoa. So, PEPCase play a key role in photosynthesis of C4 type autotrophic plant and algae and relevant processes in heterotrophic organisms except animals or fungi. To develop the high production of marine PEPCase and the CO2 fixation system, we have tried to search and isolate PEPCase genes from maine microalgae. Therefore we have already isolated two types of PEPCase cDNA clones from marine green algae Dunaliella salina (DsPEPC1 and DsPEPC2) and marine diatom Phaeodactylum tricornutum (PtPEPC1 and PtPEPC2). In order to confirm and develope that DsPEPC1/2 and PtPEPC1/2 have the higher enzyme activity, we have tried out the heterologous expression in E. coli BL21 or Origami (DE3). As a results, PEPCase recombinant proteins were successfully expressed and purified as soluble form by using His-taq affinity column.

In the present work, we have collected 19 species of macroalgae (9 Phaeophta and 10 Rhodophyta) from all around of Korea: Dictyopteris divaricata, Dictyopteris prolifera, Myelophycus cavus, Papenfussiella kuromo, Petalonia zosterifolia, Petrospongium rugosum, Rugulopteryx okamurae, Sargassum fulvellum, Sargassum muticum, Callophyllis japonica, Gloiopeltis tenax, Gracilaria longissima, Gracilaria vermiculophylla, Grateloupia asiatica, Grateloupia lanceolata, Grateloupia sparsa, Grateloupia turuturu, Grateloupia sp, and Polyopes affinis. The macroalgal species were extracted by 70% ethanol (EtOH) for 24 h and evaluated its inhibitory effects on α -glucosidase. Among ethanol extracts, Myelophycus cavus showed the most effectively inhibitory activity (IC50, 2.17 ug/ml) against α-glucosidase, followed by Sargassum fulvellum (IC50, 8.13 ug/ml), Dictyopteris prolifera (IC50, 16.66 ug/ml), Rugulopteryx okamurae (IC50, 50.63 ug/ml), and Petrospongium rugosum (IC50, 101.62 ug/ml). Furthermore, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay showed no cytotoxicity on mouse pre-adipocytes cell line (3T3-L1). These results suggest that some edible macroalgae merit further evaluation for clinical usefulness as anti-diabetic functional foods.

Photosynthetic microalgaes, living in the ocean, use a specific mechanism called carbon concentration mechanism (CCM), which is promoting capacity to fix CO2 of Rubisco [1]. In this process of CCM, Carbonic Anhydrase (CA) plays a significant role as its reversible production of CO2 or bicarbonate. Chaetoceros neogracile, an antarctic diatom, is a primary producer of the polar region. The full genomic sequences is unknown yet, but our laboratory have generated the expressed sequence tag (EST) library [2]. In our study, we searched CA genes from the constructed EST library of C. neogracile aligning with other diatom, Phaeodactylum tricornutum and Thalassiosira pseudonana. From this process, we found a partial sequence of predicted gamma type CA and obtained full length cDNA clone as CnγCA. The putative CnγCA composes of 200 amino acid in length and is supposed to be secreted to cytosol. We are able to obtain soluble expressed CnγCA to purify recombinant CnγCA, and assay CnγCA activity.