Earticle

Biological conversion of syngas (CO, H2 and CO2) has gained a widespread interest in the recent decades. The anaerobic microorgansisms called as “acetogens” utilize CO and CO2/H2 as carbon and energy sources, and produce useful fuels and chemicals. However, the low solubility of CO and its high affinity to metal ions in the CO oxidizing enzymes are big hurdles to achieve a suscessful operation of commercial sized bioreactor. It has been already reported that high concentration of CO during reaction reduces the activity of CO oxidizing enzymes and hence inhibits the microbial growth. Thus the optimum concentration of the CO in the fermentation media is desired to design and control large scale fermenters. The aim of this sudy is to evaluate the CO utilizing capacity for a newly isolated strain which is identified as Oscillibacter sp. cow-5. This strain is a strict anerobic acetogen which produces various chemicals: acetate, butyrate and small amount of ethanol and iso-valerate from CO. The strain was grown under optimum growth conditions in a batch reactor (serum vials) and a modified Monod model equation was used to determine the maxmium growth rate (μmax) and Monod constant (Ks). Simulated data were well fitted with experimental one, and two paramters, μmax and Ks, were estimated as 0.05 h-1 and 0.044 mM CO, respectivley using non linear second order regression. Meantime, the apparent dissolved CO inhibition has been found at 0.8 mM CO (equivalent to CO solubility under 1atm of PCO) from the plotting of C*vs C*/μ.

Microalgae have emerged as 3rd generation biomass for biodiesel production. However, despite importance of genetic approaches for strain improvement, molecular tools have limited. Based on this background, our research have focused on developing advanced vector systems containing inducible promoter. The main advantage of utilizing inducible promoter elements is that the gene expression of an organism can be selectively manipulated via alteration of its surroundings. Our study aimed at the construction of vector construct with inducible promoter elements which would in turn be transformed to Chlamydomonas reinhardtii to investigate the effects of glyceraldehyde 3-phosphate dehydrogenase (G3PDH) overexpression. The inducible Chlamydomonas promoter nitrate reductase (Nia1), which is activated by NO3- and repressed by NH4+ was used to drive the overexpression of gapA subunit of the G3PDH protein. pCr102 vector was used as a main back-bone vector, and the existing PSAD promoter was switched with nia1. Then, Glyceraldehyde 3-phosphate dehydrogenase (gapA) element was inserted to produce a new recombinant vector, pCrN1G3. The construct will be transformed into C. reinhardtii protoplast via glass bead method. Here, we expect that the lipid content will be increased under the presence of nitrate by the overexpression of gapA gene.

The total annual citrus production in the world is estimated to be in excess of 88 MMT, with 53 MMT of which is being orange. This corresponds to annual generation of 2.3 MMT (global production) and 0.8 MMT (US) of orange peel wastes.1 In this study, we used orange peel waste from a juice production factory to supplement the culture medium. The nutrients were extracted from the waste orange peel via aqueous extraction in the room temperature. After the optimization of extraction time, the orange peel extract was used for mixotrophic cultivation of Chlorella vulgaris. The initial nutrient content of the culture was of the follwing - 6 g/L glucose, 140 mg/L phosphate. After 7 days of cultivation, culture density reached a maximum of 2.8 (OD682). There results show that utilization of waste orange peel extract is an effective way to cultivate microalgae for biodiesel production in industrial scale. *1 MMT = 1000 MT

In this study, direct transesterification of wet Nannochloropsis oceanica assisted by ionic liquids was investigated. Two critical factors that were found to maximize the FAME yield in direct transesterification process, included the amount of methanol and the choice of the ionic liquid. Among the ionic liquids that were tested in the study, the results showed that the usage of ionic liquid with [Bmim]+ resulted in superior extraction efficiency. The FAME yield increased from 28% to 54% upon the addition of 4 ml methanol to 300 mg of wet microalgae. Other reaction parameters, such as reaction temperature, types of acid and its concentration, water content, and reaction time were also investigated. In comparison to the conventional chloroform+methanol extraction process, the direct transesterification assisted by ionic liquid, clearly is a more efficient and cost effective method for biodiesel production. (This work was supported by the Advanced Biomass R&D Center (ABC) of Korea Grant funded by the Ministry of Education, Science and Technology (ABC-2010-0029728).

Currently, the most promising microorganism used for the bio-production of butyric acid is Clostridium tyrobutyricum ATCC 25755; however, it is unable to use sucrose as a sole carbon source. Consequently, a newly isolated strain, Bacillus sp. SGP1, that was found to produce a levansucrase enzyme, which hydrolyzes sucrose into fructose and glucose, was used in a co-culture with this strain, permitting C. tyrobutyricum ATCC 25755 to ferment sucrose to butyric acid. B. sp. SGP1 alone did not show any butyric acid production and the main metabolite produced was lactic acid. This allowed C. tyrobutyricum ATCC 25755 to utilize the monosaccharides resulting from the activity of levansucrase together with the lactic acid produced by B. sp. SGP1to generate butyric acid, which was the main fermentative product within the co-culture. Furthermore, the final acetic acid concentration in the co-culture was significantly lower when compared with pure C. tyrobutyricum ATCC 25755 cultures grown on glucose. In fed-batch fermentations, the optimum conditions for the production of butyric acid were around pH 5.50 and a temperature of 37°C. Under these conditions, the final butyrate concentration was 34.2±1.8 g/L with yields of 0.35±0.03 g butyrate/g sucrose and maximum productivity of 0.3±0.04 g/L/h.

Down-regulation of microglial activation has shown significant protection against development and progression of Alzheimer’s disease. Neoechinulin A, an indole alkaloid isolated from marine-derived Microsporum sp., significantly inhibited the generation of reactive oxygen and nitrogen species in Aβ42 activated BV-2 microglia cells. We found that neoechinulina A significantly supressed the production of neurotoxic pro-inflammatory mediators in activated BV-2 cells. Moreover, the treatment down regulated protein and gene expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), TNF-α, IL-1β and IL-6. Further, activated microglia mediated apoptosis of PC-12 pheochromocytoma cells was significantly down-regulated by neochinulin A. The molecular mechanism studies revealed that neoechinulin A block the; phosphorylation of mitogen activate protein kinase (MAPK) molecule p38; apoptosis signal-regulating kinase 1 ASK-1 and nuclear translocation of nuclear factor-κB (NF-κB) p65 and p50 subunits. Collectively, these results suggest that neoehinulin A have potential to be developed as a modulator of neuroinflammatory process in Alzheimer’s disease.

The chemical pretreatment with diluted acid solution combined with enzymatic hydrolysis is considered a promising approach for the production of lignocellulosic bioethanol (Hendriks and Zeeman, 2009). Various acid pretreatment catalysts, including nitric acid (Zhang et al., 2011), phosphoric acid (Geddes et al., 2010) and hydrochloric acid (Marcotullio et al., 2011) as well as sulfuric acid (Hsu et al., 2010), have been investigated. Sulfuric acid has been commonly applied and is the least expensive. Nitric acid, on the other hand, is approximately 3-times more expensive but required a shorter reaction time to obtain high sugar concentration (Zhang et al., 2011). Furthermore, nitrate, the salt of nitric acid, could be used as a nitrogen source for fermentation process. Several researchers have observed that a variety of nitrogen sources including yeast extract and peptone (Laopaiboon et al., 2009), ammonium (Yue et al., 2012), amino acid (Albers et al., 1996) and urea (Jones and Ingledew, 1994) have effect on fermentation rate and ethanol production. In this work, rice straw, the most abundant biomass feedstock in Korea, was chosen as the raw lignocellulosic material for ethanol production. The response surface methodology (RSM) was used to optimize nitric acid pretreatment of rice straw for producing maximum xylose yield. Enzymatic hydrolysis of the remaining solid was also conducted at optimal condition to compare sulfuric acid pretreatment. In addition, we explored the effect of nitrate as the nitrogen source on ethanol yield during fermentation using Pichia stipitis.

Among feedstock of biodiesel, oleaginous yeasts have been known for outstanding abilities to grow fast and accumulate large lipid in their cells. In this study, oleaginous yeasts were isolated from the carbon abundant environments, mine area, an found optimal characteristics. Finally, 6 species were identified by performing 18S rDNA sequencing, two Saccharomyces sp., Saccharomyces cerevisiae, fungal sp., Williopsis saturnus,andTorulaspora delbrueckii. Each lipid-body of sample was visualized by confocal fluorescence microscope with nile-red solution. In order to find optimal characteristic, three culture conditions were regulated such as carbon sources, pH, and temperature (3). As a result, all the isolated yeast grew and accumulated lipid differently. The specific growth rates were observed from 0.31h-1 to 0.38h-1. On each fast grow conditions, lipid contents were measured from 5% to 11%(not optimized) (1, 2). This study confirmed that the isolated yeasts from mine area can grow and accumulate lipid. Therefore, by regulating culture condition and finding other better substrates, isolated yeasts will be promising feedstock of biodiesel.

The immobilized glucose oxidase is necessary for the development of enzymatic biofuel cells which can be applied to power sources of implantable devices as well as biosensors. We aimed to maximize the loading of glucose oxidase (GOx)on multi-wall carbon nanotubes (MWCNTs) by covalent binding. One mg of MWCNT was carboxylated and reacted with N-Hydroxysuccinimide (NHS) in the presence of 1-ethyl-3(3-dimethylaminopropyl）carbodiimide (EDC), resulting in a NHS ester, which was then reacted with primary amine (-NH2) of glucoseo xidase to form a mide cross links. The concentrations of EDC, NHS, and glucose oxidase greatly influenced on the immobilization efficiency and thus these factors were optimized using Box-Behnken design. Physical adsorption was minimized when GOx-bound MWCNT was washed with Tween-20 solution. The amount of immobilized GOx was maximum, 3.3 mg-GOx/mg-CNT, when concentration of EDC, NHS and protein was 52 mM, 430 mM and 8.7 mg/mL, respectively and washed with 5 mg/mL of Tween-20 solution. The formation of chemical bonding between GOx and MWCNT, and GOx on the surface of MWCNT was observed by FT-IR and SEM. Consumption of glucose and production of gluconic acid were observed in enzyme assay using immobilized GOx.

The seaweed Gelidium amansii was fermented to produce bioethanol after thermal acid hydrolysis pretreatment and enzymatic saccharification. Optimal pretreatment conditions of 94 mM H2SO4 and 10% (w/v) seaweed slurry at 121°C for 60 min were determined and mono sugars of 43.5 g/L with 60.7% of theoretical yield were obtained by enzymatic saccharification of the seaweed slurry after thermal acid hydrolysis. G. amansii hydrolysate was used as biomass for ethanol production by separate hydrolysis and fermentation (SHF), and the ethanol yield of 20.2 g/L was obtained by Pichia stipitis KCTC 7228. HPLC of batch fermentations showed that 5-hydroxymethylfurfural (HMF) was converted to 2,5-bis-hydroxymethylfuran. The accumulated 2,5-bishydroxymethylfuran in the medium did not affect cell growth or ethanol production. Biotransformation of HMF to less inhibitory compounds by P. stipitis KCTC 7228 could enhance overall fermentation of seaweed hydrolysates to ethanol.

In recent years, 2,3-butanediol (2,3-BDO) which is a colorless and odorless 4-carbon chemical has been applied wildly in industries such as synthetic rubber industry, antifreeze substance, food and cosmetics pharmaceuticals. Actually, researchers have already been interested in 2,3-BDO biosynthesizing mechanisms since a century ago. In 2,3-BDO synthesis pathway from pyruvate, two pathways exist with respect to different aeration environments. Pyruvate changes to acetolactate and then acetoin to 2,3-BDO directly under anaerobic condition, while the aerobic pathway is constructed by the change from acetolactate to diacetyl firstly and then diacetyl to acetoin and 2,3-BDO. Since two different pathways regulate NADH balance in different mechanism and influence greatly on 2,3-BDO synthesis, the identification of the working mechanisms in these pathways is of importance.In this study, Klebsiella pneumoniae strain was utilized to constructed 3 different mutant strains (by over-expressing budB, budA and budC genes) with respect to 2,3-BDO synthesis pathway firstly. Then, continuous cultures under aerobic and anaerobic conditions were performed using these strains in order to obtain the steady-state data. Extracellular metabolite profiles under steady-state were used to perform metabolic flux analysis for data analysis and calculations of the enzyme working mechanisms. The research helped clarify different intracellular functions under different oxygen supply situation and is beneficial for improve 2,3-BDO productivity.

Cardiovascular diseases, principally myocardial infarction, stroke and atherosclerosis, are a significant public health problem worldwide. In this study, skin gelatin of skate (Okamejei kenojei) was sequentially hydrolyzed using Alcalase and protease and was separately using a 1 kDa molecular weight cut-off membrane. Antihypertensive effect in spontaneously hypertensive rats revealed that oral administration of hydrolysate below 1 kDa can decrease systolic blood pressure significantly. Vascularity, muscularization and cellular proliferation in rat lung tissues were detected by immunohistochemical staining. Finally, two peptides responsible for ACE inhibitory activity were identified to be MVGSAPGVL (829 Da) (SP1) and LGPLGHQ (720 Da) (SP2) with IC50 values of 3.09 μM and 4.22 μM, respectively. The purified peptides are found to attenuate reactive oxygen species production and increase antioxidative enzymes in EA.hy926 cells. The purified peptides augmented the production of nitric oxide by activating endothelial nitric oxide synthase (eNOS) expression in EA.hy926 cells. The peptides significantly suppressed angiotensin II-induced release and the expression levels of endothelin-1, pro-inflammatory products and cytokines; tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), IL-6 and IL-8 in EA.hy926 cells. Molecular signaling pathway studies showed that the peptides inhibited the nuclear factor kappa B (NF-κB) p65 and p50 subunits and the phosphorylation of mitogen activated protein kinase (MAPK) pathway molecules in EA.hy926 cells. These results suggested that the cardioprotective mechanism of hydrolysate and peptides isolated from skate skin gelatin may be partly due to improvement of endothelial function associated with eNOS and oxidative stress pathway. In conclusion, the purified hydrolysate and peptides would be beneficial ingredients for nutraceuticals and pharmaceuticals against cardiovascular diseases.

Heterotrophic cultivation of microalgae can achieve much higher cell density and faster growth rate compared to photoautotrophic mode of cultivation, however the high costs of organic carbon prohibits heterotrophic cultivation from being economically feasible in industrial scales. In the present study, we considered the usage of sugar factory wastewater (SFW) as an inexpensive carbon source for cultivation of acido-thermophillic microalga Galdieria sulphuraria for the production of phycocyanin. The characteristic of SFW was studied in order to determine its suitability for use as an alternative carbon source for G. sulphuraria. In addition, we investigated the effect of various concentrations of SFW on algal growth and phycocyanin production. Phycocyanin content in G. sulphuraria (UTEX #2919) was analyzed via UV/Vis spectrometer and fluorescence microscopy. Our result indicated that the SFW can be used as an alternative carbon source for the cultivation of G. sulphuraria for the production of phycocyanin. (This work was supported by the Advanced Biomass R&D Center (ABC) of Global Frontier Project funded by the Ministry of Education, Science and Technology (ABC-2010-0029728)).

In this study, we propose a micro/nanofluidic device for the rapid quantification of bacteria (Escherichia coli). This device is comprised of a micromixer and a preconcentrator. The micromixer is used for mixing bacterial cells with tagging molecules and can be easily integrated to the preconcentrator and fabricated by polydimethylsiloxane (PDMS) replica molding method. The preconcentrator consists of two microchannels (main and sub) that are connected by the nanochannels, which can be easily fabricated by electric breakdown of a ~25 μm-thick polydimethylsiloxane (PDMS) membrane using high electric shock. For quantification of bacteria, bacteria sample is firstly mixed with fluorescent dye and continuously preconcentrated at the target position by applying the electric field through the junction of micro- and nanochannels. The concentration of bacterial sample can be quantified by measuring the fluorescence intensity at the preconcentrated region. We believe that this micro/nanofluidic biosensor will be useful for bacteria detection.

Recently, a great deal of interest has been developed by consumers towards bioactive peptides as ingredients in nutraceuticals and pharmaceuticals from natural resources. Among them, Spirulina has been known as a rich source of protein which can be hydrolized into peptides. Two bioactive peptides responsible for anti-allergic and anti-atherosclerotic activities were purified and identified as P1 (LDAVNR; 686 Da) and P2 (MMLDF; 655 Da) from gastric enzymatic hydrolysateof Spirulina maxima. In this regard, two peptides P1 and P2 were investigated for their capabilities against the activation of RBL-2H3 mast cell sensitized with DNP-specific IgE antibody and stimulated by antigen DNP-BSA. It was found that P1 and P2 significantly inhibited RBL-2H3 mast cell activation via blockade of IgE receptor (FcεRI) and suppression of ROS production. Moreover, peptides P1 and P2 exhibited the inhibitory mechanisms on newly protein and mRNA synthesis of cytokines via suppression of MAPKs and NF-κB signaling pathways. In addition, the peptides P1 and P2 have been used to examine their protective effects against early atherosclerotic responses induced by histamine in EA.hy926 endothelial cells. Interestingly, both P1 and P2 exhibited inhibitory activities on the production and expression of cytokines, lipid metabolites, chemoattractant, and adhesion molecules. Notably, the inhibitory mechanism of peptides P1 and P2 was found due to suppressing ROS production and blocking histamine receptor 1 (H1), thus inhibiting the activation of many molecules in H1-dependent signaling pathway. Taken together, both peptides P1 and P2 from Spirulina maxima have a great potential to be used in pharmaceuticals and nutraceuticals as protective agents against allergic and early atherosclerotic diseases.

A yhcN promoter based bioreporter strain was developed for the detection of phenolics in plant hydrolysates. Previous microarray data suggest that the yhcN gene was highly expressed when exposed to phenolics. To confirm this, RT-qPCR was performed and result shows that this gene was significantly up-regulated when E.coli BL21 (DE3) exposed for 10 min to 500 ppm of ferulic acid (7.2 fold) or vanillin (9.7 fold) furfural (2.3 fold), Consequently, an E. coli yhcN::lux bioreporter strain was and the resultant strain was analyzed during an exposure to hydrolysate-related phenolics and a rice hydrolysate sample. The strain had a maximum response at the time of 180 min. The strain is very responsive to furfural (25-fold) and vanillin (21-fold). The responses with different acids were also significant, with relative responses of between 4- and 16-fold. The minimum detectable concentrations were 156.12 mg/L for both furfural and 5-hydroxymethyl furfural. In tests with rice hydrolysate samples, a maximum response of 3.5 was obtained and the minimum detectable phenolics concentration, as based upon Folin-Cioalteau’s reagent, was 39 mg/L phenolics. These results illustrate that this strain can be used to monitor for the presence of chemicals within plant hydrolysate samples that may be potentially inhibitive toward downstream fermentative processes.

An efficiency pressurized liquid extraction (PLE) coupled with high performance liquid chromatography (HPLC) for quantification of biological compound tricin in black bamboo leaves (Phyllostachys nigra) was described in this study. The environmentally and health-friendly green solvents ethanol and water were used for PLE extraction. Parameters affecting extraction were optimized using the univariate method. The best extraction conditions 200℃, 50% ethanol, 20 min static time and 425 μm particle size. Compared with the traditional reflux extraction method, the optimized PLE condition showed high extraction efficiency 249 mg/100g dry leaves and it’s 19 times higher than reflux method, while taking less time and employing fewer solvents. The calibration curve for tricin was established with good linearity and correlation coefficient (r) 0.9997. To the best of our knowledge, this study is the first contribution to utilize PLE for tricin extraction. The experiment results indicated that the PLE is a promising prospect in extracting quantities tricin in plant, which can be used for pharmaceutical/biomedical applications and evaluation.

Extensive utilization of fossil fuels has raised environmental pollution, climate change, and health problems. Under this situations, microalgae could be promising alternative energy source such as biodiesel. Moreover, microalgae have strong advantage points to solve environmental pollution through CO2 fixation and wastewater treatment. Generally, microalgae increase their cell numbers under optimized condition and then accumulate lipid under stress condition. Thus, it will be important issues to increase the lipid productivity and to decrease the cultivation cost1.Based on this background, our research focused on increasing the lipid productivity under extra-cellular oxidative stress by TiO2. Basically, TiO2 could produce oxygen radicals under UV condition. By using this mechanism, we hypothesize that under stress condition for growth, lipid in microalgae could be accumulated highly and rapidly2. Chlorella vulgaris was cultivated under the various concentrations of TiO2 from 0.1 to 5 g/L and UV-A conditions. By extra-cellular oxidative stress, chlorophyll and specific growth rate was decreased. Furthermore, Fatty Acid Methyl Ester (FAME) productivity was also decreased according to increasing the concentrations of TiO2. On the contrary, under the low concentrations of TiO2 (0.1 g/L) and short induction time, FAME contents and productivity was the highest. From these results, we suggest that induction by short time and low concentration of extra-celluar oxidative stress could increase the FAME contents and productivity. This work was supported by the Advanced Biomass R&D Center (ABC) of Global Frontier Project funded by the Ministry of Education, Science and Technology (ABC-2010-0029728)

This research describe a new monitoring tool capable of concurrently evaluation of two kinds of chemical: reactive oxygen species (ROS) and non-oxidative stress-making (NOSM) compound based on lysosomal response in the Saccharomyces cerevisiae. Exposure of some organisms to oxidative stresses due to toxins alters lysosomal enzymes, thus we used intracellular lysosomes in S. cerevisiae as a biomonitoring tool to detect oxidative stresses by pesticides (glyphosate and methidathion) and heavy metals (sodium meta-arsenite and cadmium nitrate). Beside this, the effects of tetracycline and aspirin were evaluated simultaneously to examine NOSM compounds influence. The lysosomes ability to detect toxicity was evaluated by using confocal microscopy after staining lysosomes with LysoTracker. Treatment of S. cerevisiae with toxins increased the number of conspicuous and red lysosome-like organelles surrounding S. cerevisiae nucleic. The ROS levels were determined synchronously by staining the yeast cells with carboxy-H2- dichloro-dihydrofluorescein diacetate (carboxy-H2-DCFDA). The results indicated that each chemical has an optimal concentration at which the quantity of lysosomes reach the peak while the growth of yeast were not affected. It means that our method can detect the sublethal concentrations which do not inhibit the cells growth of these chemicals.

Gelidium amansii, red seaweed, has advantage of high carbohydrate contents converted to fermentable sugar such as glucose and galactose. In spite of these advantages, seaweed has problem with high salinity over 10 %. High salt concentration in the hydrolysate from G. amansii repressed fermentation process of yeasts. Therefore, acclimation of high salt concentration to yeasts is required to resolve the problem.In this study, pretreatment for the saccharification of Gelidium amansii was performed with 16 % (w/v) seaweed slurry, 1 % (v/v) H2SO4 and autoclave at 121℃ for 45 min. To obtain glucose, enzymatic saccharification was carried out using 8.4 EGU/ml of Celluclast 1.5 L and 1.2 FBG/ml of Viscozyme L for 2 days. As a result of saccharification, the galactose of 35.1 g/l and the glucose concentration of 16.8 g/l were obtained. Fermentation was performed with Candida tropicalis KCTC 7212 and Saccharomyces cerevisiae KCCM 1129 acclimated to high salt concentration, respectively. Using acclimated C. tropicalis and S. cerevisiae, ethanol concentrations of 27.6 g/l and 22.1 g/l were produced, respectively.

Natural products are growing interest in the field of nutrition and complementary medicine to prevent chronic illness or as treatment. We investigated the anti-cancer and anti-obesity properties of Green Tea seed saponin E1 (GTSSE1) on cancer cells and high fat diet induced obese mice, focusing the functional importance of GTSSE1.The anti-angiogenesis effect of GTSSE1 was examined on HUVECs. Anti-cancer and anti-obesity effect was investigated by using in-vitro and in-vivo system. Western blot analysis was also performed to evaluate the effect of GTSSE1 in angiogenic protein expression.GTSSE1 has least toxic effect on Human umbilical vein endothelial cells (HUVECs) in comparison to other saponins and significantly inhibited the proliferation of cancer cell lines. It inhibited the HUVECs cell tube formation through inhibition of VEGF-induced angiogenesis. The differentiating 3T3-L1 cells treated with various concentration of GTSSE1 had a visible decrease in lipid droplets formation measured by Oil Red O staining. Experiments in mice showed that GTSSE1 inhibits pancreatic lipase activity without hemolysis of erythrocytes, when administered orally. Also, it reduces the size of tumor in nude mice. From our investigation, we found GTSSE1 hasanti-cancer and anti-obesity properties. At dose-dependent concentration, it exerts pharmacological properties.

Oleaginous yeast has become some of the most promising feedstock for biodiesel production due to their high production efficiency [1]. However, high cost of cultivation, especially substrate cost, hinders rapid commercialization of yeast-based biodiesel [2]. In this study, microalgae (Chlorella), which is rich in nutrients and organic matters, was examined as an economic substitute for organic substances [3], and Cryptococcus curvatus, which was isolated from a fermented seafood, was used for biodiesel production. To be efficiently bioavailable, microalgae must be pretreated. Hydrodynamic cavitation reaction time and pH were identified as experimental factors, whereas growth rate was selected as response parameter. The experimental factors were optimized employing Response Surface Methodology (RSM). Growth rate of 0.605 /h was optimized at reaction time 6.88 min and pH 9.47. When Chlorella supernatant pretreated under these optimal conditions was used as a complete nutrient, 7.47. g of biomass was obtained in three days and lipid was accumulated up to 27% of dry weight.

Corn stover is one of the most abundant and cheapest lignocellulosic materials in the world. Thus, corn stover has the strong potential as a biomass feedstock for the production of fermentable sugars, which can be subsequently used to produce other valuable products such as biofuels. In general, lignocellulosic biomass can be hydrolyzed by using celluloytic enzymes. However, enzymatic hydrolysis of corn stover is usually very difficult due to its recalcitrant structure. Therefore, Dilute acid pretreatment method making the structure of corn stover much easier for the enzymes to have access is required to enhance the performance of its enzymatic hydrolysis. Moreover, it can solubilize a significant portion of the hemicellulosic component. The aim of this study is to propose optimal conditions for the dilute acid pretreatment of corn stover through over a range of conditions encompassing residence times of 1-20 min, temperature of 140-190℃, and H2SO4 concentrations of 0.25-1.0% (w/w).

Antibody (predominantly IgG) is one of the most important pharmaceutical proteins, so its production has been considered as very important issue in current biotechnology. Because of post-translational glycosylation, which is closely related to effector functions, mammalian cell systems have been widely used for the production of IgG whereas E. coli has been considered as unsuitable host. However, recent successes in the developments of aglycosylated IgG variants that do not require glycosylation for the effector functions increased the availability of E. coli as an alternative host for IgG production. In this study, we have developed a new E. coli host-vector system for the high-level production of IgG by using: i) modification of untranslated region (UTR) sequences; ii) co-expression of periplasmic foldase (DsbC). Finally, with the engineered host-vector system, fed-batch cultivations were conducted, and thus very high production yield of IgG could be achieved in a very short time cultivation.

Cultivate of marine microalgae in the ocean for bioenergy seems to have bulky benefit in many aspects over conventional biofuel production. Any successful biofuel production must only depend on the eventual energy source of the world, the sun light. Ocean can provision larger area with less effects on the circumstances, free energy for blending such as wind and tidal flow, relatively small change in temperature and unlimited amount of water and eutrophic compounds for microalgae. However, since there would be no effective method to control light intensity, which is the most important parameter for algal growth, a beware-designed floating photobioreactor will be in need of pursuance of utilize the sun energy efficiently without photoinhibition. A variety of types of floating bag closed photobioreactors were designed and erected for culturing Dunaliella tertiolecta in the coastal area near Young-Heung Island. Various photobioreactors with different light transmission (ranging from 87% to 45%) were introduced. The maximum productivity of each type of photobioreactor was in the range between 0.07 g/L/day and 0.12 g/L/day. When an extra UV cutoff film is overlaid on high-transmitting bag, the growth of the cells inside the PBRs was greaten especially when the cell concentration was low. Relatively low-transmitting films would partially block the transmission of UV, resulting in no upbeat effect on cell growth when an extra UV cutoff film was overlaid. The results distinctly showed the well-known truth that the light is the most important parameter for algal culture even on near shore area and the PBRs for ocean culture must designed carefully to utilize the maximum potential of the natural sunlight.

Alternatives to oil based fuels and chemicals are studied to increase energy security and protect of the environment through development of new technologies for the production of synthetic fuels and chemicals using renewable energy sources such as biomass. Gas fermentation is a good alternative to produce energy and chemicals from the bio masses and other industrial waste gas. Previous studies about gas fermentation have been processed in pure culture systems. However, pure culture is vulnerable to contamination and requires high cost for construction and operation; thus, mixed culture systems are required for mass production. The objective of this study is enriching the microbial community for gas fermentation and determined optimum conditions of a bioreactor to process gas fermentation in mixed culture. This study will provide feasibility of mixed culture gas fermentation system and suitable operating factors of the mixed culture bioreactor to mass produce organic acid stably and economically.

An optical biosensor for the osteoarthritis (OA) diagnosis based on the quantification of OA biomarker in human serum and urine was developed. In the OA progresses, the substances of joint such as cartilage protein are degraded and secreted into serum and urine. These cartilage degradation proteins such as C-telopeptide of type II collagen (CTX-II) are used as significant OA biomarker. The CTX-II is classified as serum CTX-II (sCTX-II) and urine CTX-II (uCTX-II) according to its existence site. Due to the structural differences between sCTX-II (homo-dimer) and uCTX-II (monomer), two different types of immunoassays such as competitive immunoassay for uCTX-II and sandwich assay for sCTX-II are employed. For the simultaneous quantification analysis of these markers, we developed a fluoromicrobeadbased multiplex guiding chip [1]. On the chip interface, CTX-IIs are bio-specifically captured and its aspect is appeared as formation of fluorescent dot. By counting the number of bead on sensing surfaces, the concentrations of CTX-II were quantified. The obtained optical signal showed good correlation with sCTX-II concentration from 6.3 to 250 pg/ml and uCTX-II concentration from 1.4 to 10 ng/ml.

AKT protein family plays vital role in signal transduction by modification of substrate activity in regulation of metabolism, cell cycle progression, transcription, cell survival, motility, apoptosis, differentiation, angiogenesis and insulin responses. AKT protein family includes AKT1, AKT2 and AKT3 whereas AKT2 and AKT3 have one isomer each. In insulin signaling process, the insulin downstream action causes insulin receptor phosphorylation and subsequently insulin receptor substrate proteins formation. In the present study, we have performed phylogenetic analysis and conservation domain analysis for these AKT family members. We applied a pioneer and fast approach to study the structural, functional and phylogenetic relationship among the AKT family member. Our study shows a rapid way to calculate amino acid sequences in terms of evolutionary conservation rates and provides vital information about regions of structural and functional importance.

Recently, microalgae have been considered as a feedstock for various types of alternative biofuel production (e.g. biohydrogen, bioethanol, biodiesel), because of their ability to accumulate high oil in their body and rapid growth rate by photosynthetic apparatus. Especially, marine microalgae also have the unique physiological characteristics to thrive under the diverse marine environments, so they are attractive sources for researchers to study new useful compounds and chemicals. Among marine microalgae, Phaeodactylum tricornutum is not only satisfied with high biomass productivity as well as reasonable oil content, but also a superior producer of PUFA (poly-unsaturated fatty acid) such as eicosapentaenoic acid (EPA, 20:5w3) and docosahexaenoic acid (DHA, 22:6w3). In order to maximize biomass productivity as well as eliminate light inhibition and limitation, specific light uptake rate was examined. Then, obtained value of specific light uptake rate was used effectively during the experiment. The other conditions (temperature, light intensity, nitrate depletion) were also altered to investigate their effects on production of fatty acid. The variation in fatty acids quantity and quality were analyzed by gas chromatograph. Under nitrate depletion with 2 days, the accumulated total fatty acids in cell body were increased from 14.0% to 39.4%. In contrast, under low light condition (at 50 mE/m2/s), nitrate depletion had no significant effect on fatty acid content. Also, a dramatic increase in PUFA (from 63.1% to 71.4% of the total fatty acid, during 4 days) was observed under low temperature. The result of this study is the strong evidences that support the potential of improving biodiesel and bioactive compound production from microalgae by manipulating growth conditions.