Earticle

Bioethanol researches can solve the problem of fossil fuels such as environment pollution and the limitation of fossil fuels. Nowadays, lignocellulosic biomass is regarded as an alternative energy source to fossil fuels. Corn stover, rice straw, switch grass and Miscanthus have been evaluated extensively as renewable biomass substrate for making ethanol. Especially, Miscanthus is considered as one of the best feedstocks for the bioethanol production because of the high carbohydrate content and the high annual biomass yield. In this study, Miscanthus was selected as the lignocellulosic feedstock for the bioethanol production and pretreated by the extrusion process using twin screw which is suitable for applying the continuous and large scale process. A central composite design of response surface method was used to optimize the condition of pretreatment, in respect to treatment temperature, sodium hydroxide concentration, twin screw speed and flow rate. The optimal conditions were found to be 78.53℃, 0.81 M, 112.67 rpm and 97.44 mL/min for temperature, NaOH concentration, twin screw speed and flow rate, respectively. Finally, 83.39% of theoretical total glucose conversion rate (TGCR) yielded after pretreatment using extrusion facility. This result constitutes a significant contribution to the continuous process of bioethanol production from lignocellulosic biomass.

In a medium containing sodium propionate, pentanoic acid was produced by Megasphaera sp. BS-4 during anaerobic fermentation of fructose. Statistical optimization of medium was carried out in order to find a medium composition for the highest production of pentanoic acid by Megasphaera sp. BS-4. According to one-factor-at-a-time (OFAT) experiments, pH and two substrates, acetate and propionate, were found to have prominent effects on the pentanoic acid production. Especially, the concentration of propionate significantly influenced the production of pentanoic acid. As the initial concentration of sodium propionate increased, pentanoic acid production also increased. Meanwhile, acetate concentration influenced cell growth of Megasphaera sp. BS-4. But high concentration of acetate also stimulated the production of hexanoic acid, not intended to produce in this study. The production of pentanoic acid increased to 10 gL-1 in a medium containing 20 gL-1 fructose and additional two substrates, 3 gL-1 of sodium acetate and 15 gL-1 of sodium propionate. Further statistical experiments followed by Response Surface Methodology (RSM) were conducted for the understanding of optimum medium composition.

The immobilized glucose oxidase is necessary for the development of enzyme biofuel cells which can be applied to power sources of implantable devices as well as biosensors. Enzyme immobilization method affects the performance of biofuel cells. We have been performing the immobilization of glucose oxidase (GOx) on the multi-wall carbon nanotubes (MWCNTs) by forming covalent binding in the presence of a coupling reagent, 1-ethyl-3(3-dimethylaminopropyl）carbodiimide (EDC) and NHydroxysuccinimide (NHS). In the preliminary experiment, we found that the concentrations of EDC, NHS, and glucose oxidase greatly influenced on the immobilization efficiency. In this study, the concentrations of these factors were optimized using response surface method. The GOx-bound MWCNT was characterized by FT-IR, SEM, and AFM analysis. Enzyme assay was performed to evaluate the immobilized GOx. Gluconic acid was analyzed by TLC or using commercial kit.

The biological production of fuels from renewable sources has been regarded as a feasible solution to the energy and environmental problems in the near future. Carbohydrates are the most abundant raw material for bioethanol production, although it may bring about raising the price of grains and simple sugars. ‘Ju-Bak’ which is the brewery slurry waste from Korean rice wine and other Korean traditional alcohol beverage, is desirable cost effective substrate for ethanol fermentation.In this study, we have investigated methods to make ethanol from raw materials such as discarded ju-bak and other starchy waste by simultaneous saccharification and fermentation(SSF). When we conducted the saccharification and fermentation with 50% Ju-Bak and 0.4% raw starch saccharifying enzyme, 13.5%(v/v) of the total alcohol content was attained at 84hr of fermentation in 5KL reactor. The results provide practical examples and give a cost effective industrial substantiation of ethanol production. This work was supported by the New &Renewable Energy of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Knowledge Economy (No. 2010T100100530).

The shortage of fossil fuel has promoted the development of alternative biofuels such as biodiesel and bioethanol. Biodiesel is an environment benign fuel produced from renewable resources such as microalgae. Fatty acid methyl esters (FAMEs), called biodiesel, can be prepared by the transesterification of triglycerides from microalgae with short-chain alcohols such as methanol as acyl acceptor. In the synthesis of FAMEs by transesterification using lipase, glycerol was simultaneously produced as a byproduct. Glycerol is subjected to coat the lipase, causing mass-transfer limitation of the reaction. Glycerol carbonate was synthesized from glycerol and dimethyl carbonate (DMC) by lipasecatalyzed transesterification. DMC can be choice of solvent for extracting oil from microalgae biomass because DMC has a good extraction solvent and the substrate for simultaneous synthesis of FAMEs and glycerol carbonate. Extraction efficiency was improved by using DMC together with methanol. The reaction conditions for the production of FAMEs were optimized.

Originally, organic solvents are used to extract lignin from lignocellulosic material in pulping process. Organosolv pretreatment is similar to organosolv pulping except the degree of delignification. This process uses either low or high boiling point solvents. Low boiling point solvents such as methanol and ethanol have been limited because they are highly volatile and flammable. As an alternative method, high boiling point solvents such as ethylene glycol and glycerol can be used. Although many studies have been carried out in the area of low boiling point organoslov pretreatment, very limited research has been performed in the high boiling point organoslov pretreatment. One of most obvious advantages for high boiling point pretreatment solvent was that the pretreatment can be conducted under atmospheric pressure, resulting in a significant decrease of the equipment cost. However, the relatively high cost of solvents significantly decreases this advantage. The main objective of this study was to investigate the effect of solvent type on the waste-paper pretreatment. Pretreatment was conducted over a range of conditions including sulfuric acid concentrations of 1~3%, temperature of 140~160, and reaction time of 10~30 minutes.

The objective of this study was to investigate the effect of acetic acid and formic acid on the ABE production by C. acetobutylicum and C. beijerinckii. The effect of co-presence of acetic acid and formic acid was also examined. In the case of Clostridium acetobutylicum, added acetic acid (3.7-9.7 g/L level) slightly increased the total ABE concentration, but drastically decreased in the presence of 11.7 g/L of acetic acid. However, C. beijerinckii was not affected on the solvents production by the acetic acid in the range of 3.7-11.7 g/L. C. acetobutylicum was more vulnerable for the tested acid conditions than C. beijerinckii. Especially, formic acid has the fatal inhibition effect on the ABE production by C. acetobutylicum. However, C. beijerinckii showed a strong tolerance for the tested acids. . In the hydrolysis process, acetic acid and formic acid can be co-existed in acid hydrolysate. Therefore, it is concluded that C. beijerinckii is more favorable than C. acetobutylicum when the ABE production is performed using lignocellulosic hydrolysate containing acetic and formic acid.

Having been exposed into the ocean, heavy metals were accumulated within organism. In the food chain, the higher rank of predator takes the more amount of heavy metals into its own body. Once accumulated, heavy metals were hardly decomposed or excreted. So heavy metals in the ocean could take place heavy metal poisoning and ecocide. As a result, this study were purposed to develop ocean heavy metal bio-sorption process using micro algae. Through the screening, some micro algae having an ability to remove heavy metals, Chlamydomonas reinhardtii, Chlorella sorokiniana, Chlorococcum littorale and Ettlia oleoabundans were selected. Then bio-sorption ability of the heavy metal containing As, Cd, Co, Cr and Zn was measured by ICP-OES. These four kinds of micro algae were immobilized in the beads to perform the continuous heavy metal sorption process.

The clogging severely takes place due to an excessive microbial growth particularly in a biofilter treating organic malodor and VOCs. The excessive microbial growth in a biofilter causes a channeling of treated waste air, which results in a rapid decrease in the removal efficiency of malodor and VOCs, and consequently frequent stoppages of biofilteroperation. A few researchers have investigated the correlation between a pressure drop caused by clogging of biofilter and its removal efficiency of malodor and VOCs. In this study, an improved biofilter system is proposed to treat a malodorous gas containing both of hydrogen sulfide and ethanol. Both of the improved biofilter system and a conventional biofilter with same effective biofilter volumes were run over 5-7 stages of operation. During their operation periods, not only their pressure drops but also their elimination capacities were compared to each other, which led to the comparative evaluation of their performances.

This paper reports on the experimental investigation carried out to evaluate the physical optimal conditions in the absorption column to remove odorous hydrogen sulfide gas. Hydrogen sulfide gas, as a highly undesirable contaminant, is most widely emitted from environmental treatment facilities. The absorbent mixed with natural second metabolites extracted from conifer trees and chemical absorbent of 2-aminoethanol was applied to remove it via chemical neutralization. The absorbent of natural second metabolites was achieved by a removal efficiency of 20 - 40 % by itself depending on the treatment conditions, but the complex absorbent mixed with 0.1 % amine chemical provides the removal efficiency of 98 %. The optimal removal efficiencies have been examined against the two major parameters of temperature and pH. This study shows that the aqueous solution by natural second metabolites can be used as an appropriate absorbent in the column absorbed for the removal of hydrogen sulfide gas.

Increasing public concerns over odors and air regulations in nonattainment zones necessitate the remediation of a wide range of odorous compounds used for industrial purpose. Currently, spraying technique using neutralizing essential oils is utilized to treat ammonia odors. The chemical analysis was performed to analyze the composition of an essential oil by GC-MS. The monoterpenes in an essential oil react with ammonia by neutralization and their reaction mechanism was elucidated. However, little information is available on the neutralization reaction with rendering air pollutants in detail. The objective of this study was to clarify the possibility of the neutralization of odors sprayed in indoor and determine the removal efficiencies in the misty aerosol by different input odor concentration. It was found that ammonia was significantly removed by the spraying technique, and the removal efficiency of ammonia was 98 %. The removal efficiencies of ammonia were also studied by the optimal conditions such as temperature and pH.

Marine algae, third-generation biomass, can be used in bioenergy production and has many advantages, which is quick-growth, lignin-free, and non-primary food crop. Carbohydrates and lipids in marine algae are possible to make theoretically almost chemicals using chemical and biological process as ever hydrocarbons of petroleum. The brown seaweed, Saccharina japonica (Sea tangle, Dasima), is widely cultivated in Korea. It has a high content of easily degradable carbohydrates, making it a potential substrate for the production of biofuels. The composed carbohydrates of brown seaweed are alginate, laminaran, mannitol, and alginate. In this study, we investigate the fermentation and hydrolysis of Saccharina japonica as potential resources for biofuel production.

Reverse Osmosis(RO) concentrated waters are generally characterized by a high concentration of total dissolved solid(TDS) and nitrate. The one of the main problems in biological treatment of RO concentrated water is a cell disfunction and destruction caused by a high concentration of TDS[1]. Aerobic granular sludges have an excellent settleability and resistance to TDS up to a concentration of 80 g/L[2]. The aim of this study was to investigate the acclimation of aerobic granule sludge to RO concentrated water. The reactors was operated in a batch mode and fed with real RO concentrated water and methanol(CH3OH) as a carbon source with a COD/N ration of 3 g COD/g N. Aerobic granular sludges was gradually acclimated during batch mode. The removal efficiency of NO3 --N is increased from 35.82% to 96.93%. The value of the rate constant, K, for the kinetic equations also increased from 0.003L/g*hr to 0.059L/g*hr. It was concluded that aerobic granular sludges are suitable for RO concentrated water treatment process.

Marine algae are abundant and renewable resource. The major constituent is carbohydrates, which is easy to degrade, and to make them a potential substrate for biofuels. In fermentation, by-products occurred serious problems to cell growth, sugar uptake, metabolic pathway and ethanol formation. Detoxification must be systematically evaluated to determine the optimum conditions due to obtain high fermentability with the lowest sugar degradation. Several process has been applied to detoxify by-products, including adsorption, over-liming, evaporation, reactive extraction, electrodialysis, and enzyme or microorganism treatment. In this work, ethanol fermentation of hydrolysate detoxified by reactive extraction was conducted to produce ethanol from marine algae.

Total amount of fishery output of Korea is approximately 3 million tons per year. Of the output, the production of fishes and seaweeds account for 75%. Every year, 28 percents (0.7 million tons) of wastes occur during the fishery process. Due to London convection, ocean disposal of fishery wastes has been strictly prohibited since 2012, treatment, which issues the recycle of fishery wastes. Fish waste contains proteins and lipids, and green seaweed is abundant in carbohydrates such as cellulose, pectin etc. To degrade these polymers simultaneously, 12 potential microorganisms were developed. By the antagonism test on nutrient broth agar plate, it was found that was no antagonism between them. To characterize the treatment of fishery waste, was operate in a 1L 5-neck flask (with 600ml of working volume) containing the mixed fishery waste of mackerel residues and green seaweed. The amount of inoculums was 12g of mixed microbes and the flask was incubated for 15 days at 40℃ and 100 rpm. With measurements of pH, DO, and ORP, the degradation of fishery waste was analyzed by the changes of concentrations of COD, TN, amino acid, and reducing sugars.

Some parts of algal polysaccharide in brown seaweed have been used as a source of health food and pharmaceutical agents.However, the remaining materials are usually wasted. To reutilize such waste, six novel strains were isolated from marine environment, and the isolated six strains clearly possessed laminarinase activity. However, high activity of laminarinase is required for the conversion of laminarin into useful oligosaccharides, tri-, di- and monosaccharides to save cost and time for saccharification. For this purpose, chemical mutation for the six strains were executed. The six cells were mutated using 30 mgl/ml of menadione, or L-ethionine, or aunomycin for 20 min at room temperature. Then, cells were washed twice with 0.85% saline. Through the plate assay, a better activity was confirmed from the mutated cells. The study for stability of the mutated cells is underway for effective degradation of laminarin.

The experiment which utilized the exhaust gas of the MGT(Micro Gas Turbine) and investigates growth of the crop according to the concentration of the CO2 was performed. The green house was constructed for four different cell for controlling the carbon dioxide concentration from 400 ppm to 1600 ppm by utilizing the exhaust gas and hot water from MGT system. Under the environmental controlled green house system, cucumber and tomato cultured with ambient 400ppm, 800ppm. 1200ppm and 1600ppm CO2 concentration. For the different CO2 concentration the growth rate of plant show different results. And there is no inhibition observed for plant culture by the supplied gas quality. Total biomass of plant increased as CO2 concentration increase, 116.1% and 114.4% of biomass was harvested in 1600ppm green house cell refer to 400ppm cell cucumber and tomato respectively. Modulate fluorometer was carried out on the plant leaves for analysis of chlorophyl, the results show that in the range of 1200ppm and 1600ppm the chlorophyl was increase and less environmental stress. For the measurment of photosynthetic efficiencies porometer was carried out on the plant, based on the obtained results for evaporation rate and pore resistance, it was suggested that 1600ppm of CO2 is optimum concentration for plant growth.

Biobutanol is produced from fermentation by Clostridium bacteria under anaerobic conditions. Concentration of butanol in fermentation (10 g/L) is significantly lower than the concentration of ethanol in fermentation (100 g/L) because butanol is toxic to the bacteria in itself, autoinhibitor. To reduce this inhibition effect, it is necessary to separate butanol from the bioreactor immediately during fermentation process. Pervaporation is one of the best ways for butanol recovery because of its high separation efficiency, low energy consumption and harmlessness to the bacteria. We synthesized the hydrophobic zeolite, silicalite-1 and prepared PDMS/silicalite-1 composited membrane in oder to increase the butanol selectivity in the continuous pervaporation process for butanol recovery. We also investigated the effects of the operating parameters, such as feed temperature, feed concentration, membrane thickness, and silicalite-1 content on flux and separation factor.

Up to now, seaweeds, particularly algae polysaccharides of red algae, and fish have been used for applications in food, feed, and biologically active compounds. By this human activity, a lots of fishery waste has been generated from industrial process, which causes environmental problems, whileas energy and its resources are exhausting. For this reason, this research has been conducted to solve marine environment and to produce useful biomaterials by developing both red algaedegrading microorganisms and fishmeal waste-degrading microorganisms. To investigate mutual interaction between these developed strains, they were perpendicularly cross-streaked on 0.8% nutrient broth agar plate, After the plate was incubated for 48 hr at 37℃, and inhibitory effect on mutual cells was checked. Inhibitory effect was not found among them. The study for treatment of mixed-type fisheries waste is under way using these microorganisms.

Optimum condition of simultaneous saccharification and fermentation (SSF) of potato tuber mash for bioethanol production was examined. Central composite rotatable design(CCRD) and response surface methodology(RSM) were employed to find the optimal condition of SSF. Among four SSF factors such as saccharifying-enzyme(Spirizyme Fuel, Novo) dosage, ammonium sulfate content in medium, incubation temperature and yeast inoculum size, saccharifying-enzyme and incubation temperature were found to be important factors by using CCRD. Using RSM, the optimal saccharifying-enzyme dosage and incubation temperature were determined to be 1.45 AGU g-1 dry matter and 31.3℃, respectively. Using the optimal condition of SSF, 14.92% (v/v) ethanol was produced after 60 hr, and all the fermentable sugar was completely used up.

The most common device used to measure fatty acid methyl ester (FAME) quantification is gas chromatography (GC). GC usually employs internal standard method since injection volume of sample is too small not to differ between each analysis. Methyl heptadecanoate and methyl nonadecanoate, which are odd carbon numbered fatty acid methyl ester, are commonly used because they don’t exist in natural plant lipids. In our study, the biodiesel from Dunaliella sp. contained C16:4, C16:3 FAME which have very similar retention time on gas chromatogram with C17:0, C19:0, the conventional internal standards for biodiesel analysis. To quantify FAME from Dunaliella sp., we used internal standards such as methyl dodecanoate, methyl pentadecanoate and methyl behenate. We determined the response factors of each internal standard and applied them into quantification and compared the results with those of using conventional internal standard, C17:0. Soybean FAME was used to confirm the feasibility of this method, it showed high accuracy.

Bacterial biofilms are associated with persistent infections due to their high resistance to antimicrobial agents. Hence, controlling pathogenic biofilm formation is important in bacteria-related diseases. Staphylococcus aureus is a versatile human pathogen and readily form biofilms on human tissues and diverse medical devices. Since S. aureus can be naturally found in multi-species communities, the supernatants of 29 bacteria have been screened to identify biofilm inhibitory components against S. aureus. The culture supernatant (1%, v/v) of Pseudomonas aeruginosa PAO1 inhibited S. aureus biofilm formation more than 90% without affecting its planktonic cell growth. The P. aeruginosa supernatant contained a high protease activity, which both inhibited S. aureus biofilm formation and detached pre-existing S. aureus biofilms. Transcriptome analyses showed that the addition of P. aeruginosa supernatant induced the expression of endogenous protease genes (aur, clp, scpA, splA, and sspA) and other important regulatory genes (quorum-sensing agrA, hemolysin hla, and histidine protein kinase saeS). Additionally, the treatment of exogenous proteinase K clearly enhanced the protease activity of S. aureus. Hence, S. aureus accelerated the expression of its own protease genes in the presence of exogenous protease to rapidly disperse its biofilm. This study proposes a possible acceleration model of protease-involved biofilm dispersal in S. aureus.

The continuing increase of oil price nowadays has created evidence that every nation have to accelerate the utilization of renewable energy in massive scale to sustain its energy security. Since energy security defined as how to equitably provide available, affordable, reliable efficient, environmentally benign, proactively governed and socially acceptable energy services to end-user, formulating policy to improve energy security is mandatory, not only because of depleting fossil resource, but also implementing diversity of energy sources. The deployment of abundant renewable energy resources can increase the security of energy supply. One of the abundant renewable energy resources in Indonesia is palm oil. This study analyses the utilization of palm biodiesel for Indonesian power generation sector in the Java-Madura-Bali (JAMALI) system. Two scenarios were created by projecting the demand and environmental impact as well as GHG emissions reduction over the next 50 years. The first scenario subjects on current energy policy, while the second scenario is to substitute of fossil fuel which is still used in the JAMALI power generation system. Effect of palm biodiesel on emission of Carbon Dioxide, Carbon Monoxide, Sulfur Dioxide, Nitrogen Oxides, Particulate Matter, and Volatile Organic Compounds were estimated for each scenario. An externality analysis to complete the environmental analysis was conducted and resource analysis of palm oil plantation based biodiesel was also estimated. Finally, the economic feasibility of palm biodiesel in the power generation sector was analyzed. Latest policies on renewable energy in Indonesia were also described to step up the development of this sector.

A mutant strain of Klebsiella pneumoniae, termed GEM167, was obtained by g-ray irradiation, in which glycerol metabolism was dramatically affected on exposure to g rays. Levels of metabolites of the glycerol reductive pathway, 1,3-propanediol and 3-hydroxypropionic acid, were decreased in the GEM167 strain compared to a control strain, whereas the levels of metabolites derived from the oxidative pathway, 2,3-butanediol, ethanol, lactate, and succinate, were increased. Notably, ethanol production was greatly enhanced upon fermentation by the mutant strain using crude glycerol derived from biodiesel industry, to a maximum production level of 21.5 g/l, with a productivity of 0.93 g/l/h. In an effort to enhance ethanol production, we engineered a mutant strain incapable of lactate formation (lactate is a major metabolite competing with ethanol for reducing equivalents) by deleting the lactate dehydrogenase gene. Production of ethanol was significantly increased in an DldhA mutant of GEM167 (28.9 g L-1 and 1.2 g L-1 h-1). Introduction of the Klebsiella pneumoniae adhE genes encoding alcohol dehydrogenase, further improved the ethanol production level from glycerol, to 31.9 g L-1; this is the highest level reported to date. These results suggested that the recombinant K. pneumoniae strain was valuable for development of industrial process to produce ethanol using waste by- product.

The cDNA of the glx1 gene encoding glyoxal oxidase 1 from Phanerochaete chrysosporium was isolated and expressed in a methylotrophic yeast Pichia pastoris. The recombinant Glx1 produced by P. pastoris showed a molecular mass of 70 kDa considerably larger than that of the native one (57 kDa) because of glycosylation of the former by P. pastoris and the enzyme activity reached the maximal value after 2 days of culture in the presence of methanol. The optimal temperature and pH of the recombinant Glx1 were at 30°C and 5, respectively. The optimal pH of decolorization of malachite green with a recombinant manganese peroxidase H4 (MnPH4) coupled with the recombinant Glx1 was 4.7. When G lx1 w as added to the reaction m ixture to produce H 2O2 over than 7.0 nmol/min/mL, this coupling reaction showed higher decolorization rate than the reaction to which 0.1 mM of H2O2 was directly added. Within 90 minutes of incubation, this coupling reaction could rapidly decolorize malachite green up to 150 uM.

The LG5 gene, encoding lignin peroxidase (LiP), was cloned from Phanerochaete chrysosporium BKM-F-1767 and expressed in protease deficient host P. pastoris SMD1168 under the control of the methanol inducible alcohol oxidase I (AOXI) promoter, which was followed by the α-factor signal peptide of Saccharomyces cerevisiae. The recombinant LiP showed a molecular mass of approximately 60 kDa, which considered larger than that of the native lignin peroxidase. The lignin peroxidase activity reached a maximum of 30 U/l after 16h induction. The optimal temperature and pH of LiP were 60oC and 4.7, respectively. This recombinant enzyme could be able to decolorize some dyes.

We cloned the cDNA of acetyl xylan esterase 2 (pcAXE2) gene from Phanerochate chrysosporium and expressed it into Pichia pastoris. The results indicated that the recombinant PcAXE2 (rPcAXE2) was efficiently produced and secreted, reaching at 938 Ul-1 after a 4 day induction. Molecular mass of the rPcAXE2 on SDS-PAGE was an approximately 63 kDa under hyperglycosylation. A biochemical analysis showed that rPcAXE2 has an optimum pH and temperature of 7.0 and 30-35oC, respectively, whereas specific activity, Km, and Vmax were 39.86 Umg-1, 92.2 μmol and 7.4 μmol min-1 ml-1, respectively. Moreover the rPcAXE2 also catalyzed the synthesis of peracetic acid (PAA) from ethyl acetate and hydrogen peroxide. The synthesized amount of PAA was 1.45 mM using 10 μg of rPcAXE2, which could be applied to the pretreatment of a cellulosic biomass in situ.

The cDNA of the glx1 gene encoding glyoxal oxidase 1 from Phanerochaete chrysosporium was isolated and expressed in a methylotrophic yeast Pichia pastoris. The recombinant Glx1 produced by P. pastoris showed a molecular mass of 70 kDa considerably larger than that of the native one (57 kDa) because of glycosylation of the former by P. pastoris and the enzyme activity reached the maximal value after 2 days of culture in the presence of methanol. The optimal temperature and pH of the recombinant Glx1 were at 30°C and 5, respectively. The optimal pH of decolorization of malachite green with a recombinant manganese peroxidase H4 (MnPH4) coupled with the recombinant Glx1 was 4.7. When Glx1 was added to the reaction mixture to produce H2O2 over than 7.0 nmol/min/mL, this coupling reaction showed higher decolorization rate than the reaction to which 0.1 mM of H2O2 was directly added. Within 90 minutes of incubation, this coupling reaction could rapidly decolorize malachite green up to 150 uM

To obtain higher biomass productivity from Chlorella sp. culture, heterotrophic cultivations which supplements organic carbon sources into the autotrophic cultures in a photobioreactor was performed. In our study, heterotrophic media was prepared by adding various carbohydrates as well as yeast extract. The biomass of Chlorella sp. obtained from the autotrophic cultivation was 1.36 g/L. However, when each of 0.01 M glucose, xylose or galactose was added, the biomass increased to 1.76, 1.42, 1.47 g/L, respectively. In addition, rhamnose did not affect the biomass production and fructose and sucrose reversely inhibited the growth of Chlorella sp. 0.8 g/L yeast extract stimulated the highest biomass production (7.78 g/L), which is five-fold higher than that from autotrophic cultivation. It was found that the addition of yeast extract increased significantly the growth rate of microalga, namely, the highest biomass was from 6 day incubation while it took 12 days in cases of the autotrophic or heterotrophic growth with carbohydrates.

Virus-like particles (VLPs) have received considerable attention for vaccine, drug delivery, gene therapy and material science applications. Recombinantly expressed VLPs of HcRNAV, a single-stranded RNA virus specifically infecting the dinoflagellate, Heterocapsa circularisquama, were described recently as a new carrier system to suppress harmful algal blooms. HcRNAV strains were divided into two types (HcRNAV34 and HcRNAV109) by complementary strain-specific infectivity. In the present study, recombinant HcRNAV34 VLPs were expressed in E. coli and purified by chitin-binding affinity column chromatography. A novel organic synthesized algicidal substance, thiazolidinedione (TD49), was packaged into HcRNAV34 VLPs by dissociation and reassociation processes and its encapsulation was detected by HPLC analysis. HcRNAV34 VLPs encapsulating TD49 specifically attached and destroyed the cells of H. circularisquam HU9433-P, which is the host of HcRNAV34 virus, but not the cells of HY9423, which is the host of HcRNAV109 virus.