Earticle

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

Ever since the pioneering research of Morse and co-workers illustrating the use of Silicatein (a protein derived from marine sponge) in the in vitro synthesis of Titania1, there has been an increasing interest in methods that mimic bio-mineralization due to their advantage in producing inorganics at ambient conditions.TiO2 is commonly used as photo-catalyst due to its non-toxicity, chemical stability, cheapness, and its high efficiency. However, owing to its relatively large band gap (~3.2 eV) its use is limited to the UV light region. By coupling the two metal oxide semiconductors TiO2 and WO3, the reduction of band gap energy can be achieved, which will allow the hybrid to be used in the visible light region.Previously in our group we identified STB1 (-CHKKPSKSC-), a constrained hepta-peptide cognitive of TiO2 through a phage surface display technique,2 and then fused this peptide to the C-terminus of a DNA binding protein LacI to form a designer protein LacI-STB1 which was then subjected to binding tests. Results showed that it has a high affinity for TiO2 nanoparticles.3 In the present study; we used this engineered designer protein to induce the formation of TiO2-WO3 hybrid metal oxide nano-particles. The synthesized hybrid nano-particles were subsequently quantified and characterized by Scanning Electron Microscope (SEM) and EDS. Compared to using peptides, this research presents a cheaper method for the bio-mimetic synthesis of hybrid metal oxides.

The lipids of algal biomass were extracted by using mixtures of ionic liquids (ILs) and methanol, and the fatty acid profiles of extracted lipids were also characterized in this work. ILs which cannot dissolve lipids were chosen selectively to extract lipids from algal biomass. Mixtures of ILs and methanol successfully dissolved biomass leaving lipids insoluble. Total contents of lipids extracted from commercial and cultivated Chlorella vulgaris were 10.6 and 11.1% by conventional Bligh and Dyer’ method, respectively, while the mixture of [Bmim][CF3SO3] and methanol could extract 12.5 and 19.0% of lipids. Multi-parameter regression by linear solvation energy relationship showed that dipolarity/ polarizability and hydrogen bond acidity of ILs play an important role in the extraction of lipids from biomass. Fatty acid profiles of extracted lipids showed wide range distribution from C14 to C24. Especially, C16:0, C16:1, C18:2, and C18:3 fatty acids were dominant in the lipids extracted by using ILs. It means that the extracted lipids from C. vulgaris can be used as a source of biodiesel production. These results show high efficiency of ILs-mediated extraction of lipids from algal biomass.

Two Chlamydomonas reinhardtii strains whose cell walls were genetically removed were tested and compared to C.reinhardtii wildtype in lipid extraction process. The two mutants and the wildtype strains had been maintained in TAP agar media, and they were inoculated in liquid TAP media in order to obtain the same condition of cell growth. Growth curves of the strains were obtained. After the same period of cultivation, they were harvested using centrifuge. Lipid of harvested algae was extracted and converted to biodiesel simultaneously using a modified in-situ transesterfication technique from Wahlen et al[1]. The converted biodiesel was analyzed using gas chromatography. The supernatant of centrifuged samples were also analyzed in order to check whether the mutants having no cell wall secrete lipid.

Jerusalem artichoke, one of the low-requirement sugar crops, is an inexpensive and wildly available non-grain raw biomaterial containing cellulose and hemicelluloses in the stalk and a high content of inulin in the tuber. However, the lignocellulosic component in Jerusalem artichoke stalk reduces the fermentability of the whole plant for efficient bioethanol production. In this study, Jerusalem artichoke stalk was pretreated by diluted acid treatment and then enzymatically hydrolyzed. The optimum pretreatment conditions were at 80°C, 6 h retention time and 4% sulfuric acid solution to dry biomass loading of 20:1 (wt/wt). The cellulose and hemicellulose from the tuber were released into the acidic solution. During enzymatic hydrolysis using Celluclast®1.5L (60 FPU/ g dry biomass) and Novozyme 188 (30 CBU/ g dry biomass), approximately 90% of glucan and xylan were converted to glucose and xylose. It was close to the maximum yield within 48 h of enzyme hydrolysis. Soluble sugars present in the hydrolysate of the stalk were extracted with hot water, and then the extract was combined with the lysate of Jerusalem artichoke tuber for fermentation. Batch simultaneous saccharification and fermentation by Kluyveromyces maxianus, an inulinase activity yeast, was effectively performed and over 10 ml ethanol per 100 ml of the fermented medium was yielded, the ethanol productivity was over 0.35 g ethanol/ g of dried Jerusalem artichoke and over 95% of total sugar was used by the yeast strain. This result showed that combining tuber to the stalk hydrolysate was a useful strategy of whole biomass utilization for effective fermentation of bioethanol production from Jerusalem artichoke.

K. pneumoniae wild type is capable of producing 2,3-butanediol from glucose by fermentation, but pH, oxygen rate, intracellular NAD+-NADH balance, and etc are the main obstacles. In order to obtain an microorganism with abundant 2,3-BDO yield, the wild type K. pneumonia were screened [1], [2]. Also 200ml flask fermentation with 36 g/L glucose feed at 37℃, 250 rpm was performed for wild type strain of the selected K. pneumoniae. As a result the selected K. pneumonia strain showed an promising 2,3-BDO productivity. In addition, in order to achieve the optimal medium condition for 2,3-BDO production, 200ml flask fermentation such as; temperature, glucose concentration, and etc, were conducted.

Because of rapid development of petroleum-based industry, there are many negative effects: decrease of reserve of petroleum and environmental pollution. Bioethanol has been recognized as a promising alternative energy source. Synthesis gas (syngas) can be produced by the gasification of biomass at high pressure and temperature, and also it is utilized by microorganisms that can transform syngas into biochemical feedstocks such as fatty acids and alcohol. The main purpose of this research is to isolate ethanogenic acetogens from environmental samples. In the research, a gas-lift syngas fermentation system was used for microbial isolation. The gas-lift syngas fermentation system has enhanced overall volumetric gas mass transfer coefficient (kLa) by installing sintered glass filter 1). Four animal feces (cow, rabbit, chicken, and goat) were used for microbial source for isolation 2). Successful enrichment of syn-gas utilizing microbial consortia was constructed using all inocula within 2 weeks. Hungate technique was employed to cultivate and isolate putative syn-gas utilizers. As a result, 18 isolates were isolated and identified by 16s rRNA gene sequence for clarifying dominant strain in animal feces. Hence, our present research, using gas lift syngas fermentation system, could be utilized into isolation of ethanogenic acetogens from various environmental sources.

To prodcue ethanol from concentrated sweet sorghum juice for bio-ethanol production, the effect of fermentation medium was investigated by response surface methodology (RSM). A 23 factorial central composite design (CCD) was chosen to explain the combined effects of the medium constituents, viz. nitrogen (adjusted by adding (NH4)2SO4),phosphorus (adjusted by adding KH2PO4), and sugar concentration.Optimum sugar condition was 29.28 BX°. Additional supplement of nitrogen and phosphorus source was not required. The model predicted that maximum ethanol production rate under the above optimum conditions was 2.2 g/lh.

Optimum CO2 concentrations for cultivation of Chlorella sp., D. salina and Dunaliella sp. were 1, 3 and 1 %, respectively. Specific growth rates(μ) of Chlorella sp., D. salina and Dunaliella sp. were 0.58, 0.78 and 0.56 /day, respectively, and biomass productivities were 0.28, 0.54 and 0.30 g dry cell wt/L/day, respectively. During growth, CO2 fixation rate of Chlorella sp., D. salina and Dunaliella sp. were 42.8, 90.9 and 45.5 mg/L/day, respectively. To investigate the effect of organic substrate on biomass production of microalgae, glucose, xylose, rhamnose, fructose, sucrose, and galactose were applied to the culture medium. In the mixotrophic cultivation of Chlorella sp., only glucose increased biomass productivity from 0.28 to 0.51 g dry cell wt/L/day. However, Dunaliella salina and Dunaliella sp. were not stimulated by any of the organic substrates tested.

The use of thermotolerant fuel ethanol-producing yeast has the advantage in reducing cooling costs, faster fermentation rates, and decreased contamination chances during fermentation. Also high-temperature fermentations may help to make the simultaneous fermentation and ethanol extraction process more suitable for fuel ethanol production. Efforts were made to improve thermotolerance and ethanol production of industrial polyploid yeast Saccharomyces cerevisiae by mutation. The yeast strain had the optimal ethanol production at 30℃. The cells of yeast were treated with UV or NTG at the dosage for 10% survival and improved thermotolerant colonies were isolated. The cells could grow at 43℃ while the original strain could not grow. The ethanol productions of several mutant colonies were examined using yeast-peptone broth containing 23% glucose. The thermotolerant yeast strain were produced more ethanol than the original wild type control strain at 36 and 39℃ by up to 5%~10%. Also the rate of ethanol production by the mutant strains were faster than that by contol strain.

The objective of the work was to study the effect of C/N ratio and type of aeration on nitrification rates of activated sludge by advanced wastewater treatment process. The activated sludge from 26 wastewater treatment plants were collected and grouped through A-H depending upon the type of industry and the C/N ratio. The experiment was carried out in lab-scale (20 liters) and pilot plant scale (8000 liters). For the case of pilot plant scale, two type of aeration were studied namely side aeration and overall aeration. The specific nitrification rate (SNR) was calculated and it was correlated with the C/N ratio and the aeration type. No inverse relation between the C/N ratio and the SNR had been established. This result disagree with the earlier study. The SNR for overall aeration was more compared with side aeration for the same dissolved oxygen level in both type of aeration. The difference between SNR of two different type of aeration was about 8.8%.

As energy and environment have become urgent issues, there has been increasing needs to develop alternative energy source, such as microalgal bio-fuel. In this study, we investigated the growth and lipid contents of microalgae Nannochloris oculata under various environmental conditions for biodiesel production. Our results indicated that biomass productivities of N. oculata were correlated with increasing nitrogen concentrations up to 37.5 ppm. High irradiance using 160∼･180 μmol/m2 resulted in higher biomass yields than low irradiance of 70∼ｦ80 μmol/m2. Biomass productivities increased further by manipulating surface to volume ratio (S/V), which in turn enhanced light penetration. Finally, optimal biomass productivities (1.04 g/L·day) were achieved by addition of yeast extract. In addition, we investigated lipid contents and lipid profiles of N. oculata corresponding to the different growth conditions and our results suggested the feasibility of Nannochloris oculata for the biodiesel production.

Lignocellulosic biomass is a potential alternative source of bioethanol for renewable energy. The oil palm empty fruit bunch (OPEFB), which is wastes in oil palm factories, is one of a potential lignocellulosics to be converted to bioethanol. In this study, the OPEFB was pretreated with 2% sodium hydroxide and converted to ethanol by simultaneous saccharification and fermentation using two recombinant Saccharomyces cerevisiae strains secreting Trichoderma reesei endocellulases and Saccharomycopsis fiburigera beta-glucosidase, respectively. Ethanol productivity of these strains was higher than that of wild-type S. cerevisiae with a reduced amount of commercial cellulases. This results indicate that the consolidated bioprocessing using Saccharomyces cerevisiae secreting cellulases allows economic production of ethanol from OPEFB.

Recently, the potential use of microalgae as a source of biomass for fuel production has been focused because microalgae have advantages as a feedstock for energy production; they can be cultivated easily and are not considered to be human food sources. In this study, the anaerobic digestion (AD) process using microalgae as a substrate was investigated to see the possibility of methane production. Microalgae should be pretreated before adding into AD process in order to improve the biodegradability of organic materials. Herein, thermal, chemical, ultrasonic, and combined pretreatments were examined to find the optimum condition of pretreatments. The result showed that thermal, alkali, ultrasonic pretreatment were relatively effective, and their combinations were more effective than individual pretreatment in terms of cell lysis activity. Vial tests were performed by two combined (alkali/ultrasonic, ultrasonic/thermal) and two individual (thermal, ultrasonic) pretreated biomass of Dunaliella sp., and two mesophilic sludges obtained from municipal wastewater treatment plant (WTPSL) and local brewing company (BRSL) were used for inoculum sources. Pretreated biomass was spiked two times into vials containing anaerobic medium and inoculum sources, and methane production was measured up to 60 days. Consequently, as a control 0.752 and 0.198 L CH4/g TCOD were generated from WTPSL and BRSL itself, respectively. Vial containing pretreated microalgae produced 0.7–.2 times higher methane yields than negative control. Results also indicated that vial with combined pretreated microalgae extracted more methane gas compared to vial with un-pretreated microalgae. Therefore, it was demonstrated that microalgae have a potential to be a substrate in AD, and pretreatment have a positive effect on extracting more methane gas in AD.

Forty species of green microalgae (Chlorella spp., 36 species; Scenedesmus spp., 3 species; and Nannochloris sp.) arbitrarily chosen from the Korea Collection for Type Cultures were studied for their abilities of CO2 biofixation and lipid synthesis using coal-fired flue gas. Twelve species out of the forty species tested were selected based on biomass productivity and/or intracellular lipid content (mg fatty acids/g cell) using flask cultures with atmospheric CO2 and subsequent bubble-column cultures with 10% CO2 under in-door conditions. When further cultivated with the flue gas (12~15% CO2) from coal-power plant under out-door conditions, only two Chlorella species showed significant biomass productivities of 0.24 and 0.10 g cell/L/day, respectively. Lipid content (52~167 mg fatty acids/g cell) and fatty acids composition (mainly myristic acid, palmitic acid, myristoleic acid, stearic acid, oleic acid, linoleic acid, and linolenic acid) were largely varied depending on the species. This study indicates that many species of green microalgae have the ability to utilize CO2 at atmospheric and/or high concentrations but only two species have potentials for the biofixation and lipid production using CO2 in coal-power plants

Giberellic acid (GA3) and abscisic acid (ABA) are phytohormones. In higher plants these phytohormones affect the growth of plants. It is usually known that GA3 enhances cell division and controls the growth of the plants and ABA is the stress hormone which enhances tolerance to stress condition. Some articles have shown that these phytohormones also affected to microalgae. Especially, ABA induced morphological change of Haematococcus pluvialis from vegetative cell to cyst form in stress condition. To improve astaxanthin productivity, the complex stress condition is used, light stress, nutrient deficiency and so on. In this study, we use GA3 and ABA in salt and light stress condition to induce astaxanthin in Haematococcus pluvialis.

Current ethanol production processes using crops such as corn and sugar cane have been well established. However, the utilization of cheaper biomasses such as lignocellulose could make bioethanol more competitive with fossil fuels while avoiding the ethical concerns associated with using potential food resources. In this study, miscanthus, a lignocellulosic biomass, was pretreated using NaOH to produce bioethanol. The pretreatment and enzymatic hydrolysis conditions were evaluated by response surface methodology (RSM). The optimal conditions were found to be 145.29 °C, 28.97 min, and 1.49 M for temperature, reaction time, and NaOH concentration, respectively. Enzymatic digestibility of pretreated miscanthus was examined at various enzyme loadings (10-70 FPU/g cellulose of cellulase and 30 CbU/g of β-glucosidase). Regarding enzymatic digestibility, 50 FPU/g cellulose of cellulase and 30 CbU/g of β-glucosidase were selected as the test concentrations, resulting in a total glucose conversion rate of 83.92%. Fermentation of hydrolyzed miscanthus using Saccharomyces cerevisiae resulted in an ethanol concentration of 59.20 g/L at 20% pretreated biomass loading. The results presented here constitute a significant contribution to the production of bioethanol from miscanthus.

By using green fluorescence protein as a selective marker of the successful transformed cells, we tried increasing the algae oil content by using glycerol-3-phosphate dehydrogenase gene (GPD1) from baker yeast with PIRES2-EGFP vector and Eppendorf Multiporator Electroporation System. We used mixed algae culture Scenedesmus spp. and Ankistrodesmus spp. in Beijernik medium. We attempted four different electro pulses 1.5, 1.8, 2, and 2.3 KV and results were analyzed by using fluorescence microscope with Nile Red and flow cytometry. The most successfully transformed species was Scenedesmus spp. at pulse rate of 2 KV. By using three filters of the flow cytometry detector FL1 vs. FL2 and FL3 vs. FL2, we found oil content in the transformed strain was significantly increased than wild type strain. However, after few generations, transformed cells with green fluorescence phenotype were very low (~20:30 cell per ml). Since we didn't add any type of antibiotics in the media to make selection and stabilization of the plasmid vector inside the algae cells, this may be the reason that we tested before the sensitivity of Scenedesmus spp. and Ankistrodesmus spp. mixed culture to kanamycin and neomycin antibiotics. We recorded wild type strains, used, can grow well on kanamycin and neomycin.

Insulin, in nature, has a stimulatory effect on microorganisms. This causes speeding up in the sugar metabolism and also triacylglycerol anabolism increasing rapid growth rate and formation of high amount of oil content. On the other hand, we observed in our study that insulin may cause indirect activation of triacylglycerol lipase by making the cell in permanent needs to the energy source. Thus, cells consume all its sources of fuel which is accumulated inside the cells like lipids, proteins and carbohydrates. After studying the effect by using two type of insulin (Humulin 70\30 and insulin human expressed in yeast) in different concentrations on microalgae Chlorella spp., we found that incertain concentrations of insulin (1:2.6 micro unit Humulin 70\30 per ml, 1:3.3 micro unit yeast insulin per ml), algae expressed on growth rate and cell size. This suggests that algae have high optical density and smaller cell size than control. We, therefore, studied the effect of insulin under lipase inhibition by using Triton WR 1339 (Tyloxapol) which was used in different concentrations with and without insulin. We found strong regression in the growth rate with increasing Triton concentration. However, we also recorded that the cell size under the effect of Triton and Triton-insulin was higher than the cell size under the effect of insulin alone and even higher than the control sample. The oil content, also, was higher than the control sample and the cells under just insulin effect.

The world demand of renewable bioenergy as an alternative transportation fuel is greatly increasing. Research for bioethanol production is currently being progressed intensively throughout the world. Rice straw is one of big candidate for bioethanol. 5.6 million ton/year of rice straw is produced in Korea. If we use 3 million tons of rice straw for bioethanol production, it can replace more than 5% of the gasoline as transport fuels.In this study, the effective pretreatment technology for lignocellulosic biomass is presented. We newly developed temperature and pressure-controlled expansion reaction system and CO2-mixed physicochemical pretreatment method. This system consists of a reactor with high temperature and pressure in upper side, and a separator with low temperature and pressure in bottom. To hydrolyze biomass, 3MPa of CO2 was loaded into the reactor. After reaction, the sample was spouted into the separator with 6MPa N2 pressure. Rice straw material, milled into 0.3mm and drying at 50℃ for one day was used for pretreatment. At that time, the water content of the sample was under 5%. Compositional analysis of rice straw was performed by NREL protocol, and it consisted of 36% cellulose, 21% hemicellulose, 20% lignin, and 12% ash. The sample was pretreated with 15% ammonia solution at 150℃ for 20, 40 and 60 minutes using our new developed pretreatment system. Especially ammonia and CO2 mixed solution were used for the pretreatment of rice straw. As a result of the pretreatment, the sample was changed to 46% cellulose and 22% hemicellulose with 70% solid remaining. In conclusion, the recovery of cellulose and hemicellulose from this new system increased by 8% and 22%, respectively, compared with one of control.

This study was carried out to improve the efficiency of conventional biopanning protocol based on batch adsorption. Chromatographic biopanning protocol using IDA monolithic column was used in search of copper ion binding peptide from a phage-displayed peptide library. Although a number of metal binding peptide sequences have been known, biopanning protocol using chromatographic matrix has hardly been reported. Chromatographic biopanning can be very effective way to find the strongest binders to target components fast and conveniently. After several rounds of positive and negative screening step, phage particles binding to copper were isolated

To solve the global energy crisis in fossile fules, microalgal biomass as a renewable and sustainable energy source has been widely studied and came into spotlight due to its high growth rate as well as rich oil content. In this study, we investigated the feasibility of simultaneous wastewater treatment and biodiesel production using Chlorella vulgaris. C. vulgaris was cultivated in municipal wastewater as a culture medium and tested under various conditions for nutrient removals and biomass productivities. Either exponentially growth or stationary phases of C. vulgaris from the seed culture were selected and transferred into 100%, 50%, and 10% of pre-treated wastewater. As the results, approximately 90% and 100% removal of total nitrogen and phosphorus could be achieved. Interestingly, highest biomass productivity was rather obtained in undiluted and untreated wastewater. Based on these results, we could further study continuous or semi-continuous process to facilitate the biomass productivity of C. vulgaris.

In this study biodiesel was produced from rapeseed oil and lard oil by non-catalytic process using supercritical properties. The biodiesel obtained was analyzed for the content and composition. The optimum values for the reaction parameters in the supercritical process were reaction temperature 340 ℃, pressure 300bar, reaction time 5min, and stirring speed of 500rpm. The maximum yield of fatty acid methyl ester obtained for rapeseed oil was 87.1wt% and for lard oil was 91.2wt%. In addition, it is confirmed that biodiesel produced by non-catalytic process was similar in quality as that of the catalytic process. Therefore, biodiesel produced by supercritical non-catalytic process could be used as a transportation fuel.

The acute toxicity assessment of new algicides, TD49 and TD53, to the marine ecological system was conducted. The toxicity assessment used Ulva pertusa Kjellman and 3 species that represent the marine ecological system, and the results were compared by E(L)C50, NOEC and PNEC. In the acute toxicity assessment using the Ulva, the E(L)C50, NOEC and PNEC of TD53 were 1.65 μM, 0.08 μM and 1.65 nM, and those of TD49 were 0.18 μM, 0.63 μM and 0.18 nM, respectively. In assessment using S. costatum, D. magna and P. olivaceus, EC50 of TD53 showed 1.53 μM to S. costatum, 0.61 μM, and 2.14 μM, respectively. Indicating that D. magna is most sensitive. The calculated NOEC and PNEC to D. magna was 0.25 μM and 6.10 nM. E(L)C50 of TD49 to the three species were 0.34 μM, 0.68 μM, and 0.58 μM, respectively. The PNEC value was lowered as more kinds of species were employed as the subjects due to application of lower uncertainty factors. Also, a little difference in the chemical structures of the algicides showed significantly different sensitivity and specificity to the toxicity of the employed species.

One of the main objectives for understanding the process of decomposition of land filled wastes and the characteristics of leachate, which is generated during the process, is to dispose wastes more safely and more efficiently. However, endocrine disruptors which exist in low concentration are not included in categories for investigation on water and thus are being disposed without any treatment. In this research, endocrine disruptors within leachate and treated water generated from nineteen land fill sites of Jeollanamdo, South Korea, were inspected. Inspected substances are Bisphenol-A(BPA), Styrene monomer(SM), Styrene dimer(SD), and Styrene trimer(ST). According to the result of analysis on leachate and treated water, the concentrations showed: BPA 0.51~6,621.44㎍�/ℓ, SM 0.00~0.21㎍�/ℓ, SD 0.06~11.72㎍�/ℓ, and ST 0.18~1.46㎍�/ℓ, respectively.

Bioethanol from lignocellulosic biomass is regarded as an alternative fuel to the finite fossil fuel. Rice straw, corn stover, switch grass, and Miscanthus have been evaluated extensively as renewable biomass substrate for producing ethanol. But the pretreatment process is essential required because of the physical and chemical barriers such as lignin that inhibit the accessibility of enzyme to the cellulose substrate. In this study, Miscanthus was used as the lignocellulosic biomass for the bioethanol production. Biomass was pretreated by using inorganic salts in aqueous solution such as NaCl, CaCl2, and FeCl3 in order to investigate the effect of inorganic salts on the pretreatment process of Miscanthus for the bioethanol production. The change in morphology of the feedstock after pretreatment was observed by using scanning electron microscope (SEM). The digestibility of glucose was determined by high performance liquid chromatography with refractive index detector.

Methods of producing bioethanol, a promising biofuel from renewable sources, have gained increasing attention because of concerns about rising oil prices and global environmental problems. While cassava is considered a particularly attractive raw material for bioethanol production, it is a starchy substrate, and pretreatment is needed to saccharify and liquefy the starch so that microorganisms can process it. Moreover, filtering is generally needed to keep suspended solids from interrupting continuous processing. We present a simultaneous saccharification and continuous fermentation (SSCF) process using the self-flocculating yeast Saccharomyces cerevisiae CHFY0321 and sludge-containing cassava mash. We demonstrate the potential of this process as a cost-effective method of producing bioethanol from cassava without additional saccharification, inoculation, or filtering processes.

Marine biomass has lots of carbohydrate. Moreover, it is easy to degrade, and to make them a potential substrate for biofuel and chemical production. These are well known as abundant and renewable energy source. Carbohydrates in marine biomass are major constituent. But their structure and composition of mono-sugar are more complex and copolymerized than that of lignocellulosic resources. In lignocellulosic biomass, carbohydrates hydrolyzed into mono-sugar such as glucose, xylose, fructose, galactose, arabinose, etc., by simple or complex hydrolysis or saccharification methods. However, the enzymatic saccharification of marine biomass requires new enzymes which are different to cellulosedegrading enzymes. Generally, the extreme condition in acid-catalyzed hydrolysis of carbohydrates caused the occurrence of fermentation inhibitors such as 5-hydroxymethylfurfural, levulinic acid, furfural, acetic acid and formic acid. In this study, we investigate the formation kinetics of fermentation inhibitors in hydrolysis process with marine biomass, Laminaria, Undaria, Hizikia fusiforme, and Enteromorpha, used as potential resources for biofuel production.

To investigate the efficacy of Fe biosorption, bacterial communities in coal mine drainage were evaluated by constructing 16S rRNA gene libraries. The acid and organic solvent were used to increse adsorption ability on the surface of the cell membrane. acid (sulfuric acid, hydrochloric acid, and nitric acid) were used to activate functional groups of the outer cell membrane of Klebsiella oxytoca and to permeabilized cell and organic solvents (chloroform, toluene, acetone, and ethanol) activate the functional group of outer membrane and inner membrane of Klebsiella oxytoca. Treatment with 0.1% sulfuric acid was the most effective acid treatment, supported by results from SEM and FT-IR. Treatment with organic solvents resulted in lower permeability barriers due to falling out lipids of the cell membrane. Therefore, permeabilized cells showed higher absorption of iron with low cell viability. The residual amounts of phospholipids of the cell membrane were measured to investigate the mechanism of the improved permeability

Roadside trees that have been chronically influenced by air pollutants need to build up their resistance and develop a tolerance. Antioxidant enzymes and cell membrane stability have been widely used to differentiate stress tolerance. For comparative studies, plant samples of spindle tree, Euonymus japonica, were collected from a clean control area (Kijang) and an industrial area (Onsan) which is one of the heavily polluted areas in Korea. The leaves were irradiated with 0, 50 and 100 Gy of gamma rays from a 60Co isotopic source, and evaluated for the level of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and lipid peroxidation (LPO). In this study, air pollution-stressed plants showed better adaptation to ionizing radiation (IR) stress. The plant from Onsan exposed to 50 and 100 Gy of IR didn't show any changes of antioxidant enzymes (SOD, CAT and GR) and the LPO due to their enhanced antioxidant capacity than those grown in Kijang. Until 6 hours after irradiation, the samples from Kijang showed apparent increase in the enzymes activities and the level of LPO. These biochemical differences after irradiation between plants which were adapted to their own air environment can be applied to the plant bioassay as an environmental monitoring technique.