Optimization of biodiesel production from castor oil using response surface methodology.

Jeong, Gwi-Taek,Park, Don-Hee Humana Press ; Humana Press ; OCLC 2009 Applied biochemistry and biotechnology Vol.156 No.1

<P>The short supply of edible vegetable oils is the limiting factor in the progression of biodiesel technology; thus, in this study, we applied response surface methodology in order to optimize the reaction factors for biodiesel synthesis from inedible castor oil. Specifically, we evaluated the effects of multiple parameters and their reciprocal interactions using a five-level three-factor design. In a total of 20 individual experiments, we optimized the reaction temperature, oil-to-methanol molar ratio, and quantity of catalyst. Our model equation predicted that the following conditions would generate the maximum quantity of castor biodiesel (92 wt.%): a 40-min reaction at 35.5 degrees C, with an oil-to-methanol molar ratio of 1:8.24, and a catalyst concentration of 1.45% of KOH by weight of castor oil. Subsequent empirical analyses of the biodiesel generated under the predicted conditions showed that the model equation accurately predicted castor biodiesel yields within the tested ranges. The biodiesel produced from castor oil satisfied the relevant quality standards without regard to viscosity and cold filter plugging point.</P>

Production and characterization of biodiesel from tung oil.

Park, Ji-Yeon,Kim, Deog-Keun,Wang, Zhong-Ming,Lu, Pengmei,Park, Soon-Chul,Lee, Jin-Suk Humana Press ; Humana Press ; OCLC 2008 Applied biochemistry and biotechnology Vol.148 No.1

<P>The feasibility of biodiesel production from tung oil was investigated. The esterification reaction of the free fatty acids of tung oil was performed using Amberlyst-15. Optimal molar ratio of methanol to oil was determined to be 7.5:1, and Amberlyst-15 was 20.8 wt% of oil by response surface methodology. Under these reaction conditions, the acid value of tung oil was reduced to 0.72 mg KOH/g. In the range of the molar equivalents of methanol to oil under 5, the esterification was strongly affected by the amount of methanol but not the catalyst. When the molar ratio of methanol to oil was 4.1:1 and Amberlyst-15 was 29.8 wt% of the oil, the acid value decreased to 0.85 mg KOH/g. After the transesterification reaction of pretreated tung oil, the purity of tung biodiesel was 90.2 wt%. The high viscosity of crude tung oil decreased to 9.8mm(2)/s at 40 degrees C. Because of the presence of eleostearic acid, which is a main component of tung oil, the oxidation stability as determined by the Rancimat method was very low, 0.5h, but the cold filter plugging point, -11 degrees C, was good. The distillation process did not improve the fatty acid methyl ester content and the viscosity.</P>

Pretreatment characteristics of waste oak wood by ammonia percolation.

Kim, Jun-Seok,Kim, Hyunjoon,Lee, Jin-Suk,Lee, Joon-Pyo,Park, Soon-Chul Humana Press ; Humana Press ; OCLC 2008 Applied biochemistry and biotechnology Vol.148 No.1

<P>A log of waste oak wood collected from a Korean mushroom farm has been tested for ammonia percolation pretreatment. The waste log has different physical characteristics from that of virgin oak wood. The density of the waste wood was 30% lower than that of virgin oak wood. However, there is little difference in the chemical compositions between the woods. Due to the difference in physical characteristics, the optimal pretreatment conditions were also quite different. While for waste oak the optimum temperature was determined to be 130 degrees C, for virgin oak wood the optimum pretreatment was only achieved at 170 degrees C. Presoaking for 12 h with ammonia solution before pretreatment was helpful to increase the delignification efficiency.</P>

Lipase-catalyzed transesterification of rapeseed oil for biodiesel production with tert-butanol.

Jeong, Gwi-Taek,Park, Don-Hee Humana Press ; Humana Press ; OCLC 2008 Applied biochemistry and biotechnology Vol.148 No.1

<P>Biodiesel is a fatty acid alkyl ester that can be derived from any vegetable oil or animal fat via the process of transesterification. It is a renewable, biodegradable, and nontoxic fuel. In this paper, we have evaluated the efficacy of a transesterification process for rapeseed oil with methanol in the presence of an enzyme and tert-butanol, which is added to ameliorate the negative effects associated with excess methanol. The application of Novozym 435 was determined to catalyze the transesterification process, and a conversion of 76.1% was achieved under selected conditions (reaction temperature 40 degrees C, methanol/oil molar ratio 3:1, 5% (w/w) Novozym 435 based on the oil weight, water content 1% (w/w), and reaction time of 24h). It has also been determined that rapeseed oil can be converted to fatty acid methyl ester using this system, and the results of this study contribute to the body of basic data relevant to the development of continuous enzymatic processes.</P>

Biodiesel production from various oils under supercritical fluid conditions by Candida antartica lipase B using a stepwise reaction method.

Lee, Jong Ho,Kwon, Cheong Hoon,Kang, Jeong Won,Park, Chulhwan,Tae, Bumseok,Kim, Seung Wook Humana Press ; Humana Press ; OCLC 2009 Applied biochemistry and biotechnology Vol.156 No.1

<P>In this study, we evaluate the effects of various reaction factors, including pressure, temperature, agitation speed, enzyme concentration, and water content to increase biodiesel production. In addition, biodiesel was produced from various oils to establish the optimal enzymatic process of biodiesel production. Optimal conditions were determined to be as follows: pressure 130 bar, temperature 45 degrees C, agitation speed 200 rpm, enzyme concentration 20%, and water contents 10%. Among the various oils used for production, olive oil showed the highest yield (65.18%) upon transesterification. However, when biodiesel was produced using a batch system, biodiesel conversion yield was not increased over 65%; therefore, a stepwise reaction was conducted to increase biodiesel production. When a reaction medium with an initial concentration of methanol of 60 mmol was used and adjusted to maintain this concentration of methanol every 1.5 h during biodiesel production, the conversion yield of biodiesel was 98.92% at 6 h. Finally, reusability was evaluated using immobilized lipase to determine if this method was applicable for industrial biodiesel production. When biodiesel was produced repeatedly, the conversion rate was maintained at over 85% after eight reuses.</P>

Mobilization and biodegradation of 2-methylnaphthalene by amphiphilic polyurethane nano-particle.

Kim, Young-Bum,Kim, Ju-Young,Kim, Eun-ki Humana Press ; Humana Press ; OCLC 2009 Applied biochemistry and biotechnology Vol.159 No.1

<P>Amphiphilic polyurethane (APU) nano-particle enhanced the mobilization of 2-methylnaphthalene (2-MNPT) in soil. Significant increase in the solubility of 2-MNPT was achieved. The molar solubilization ratio was 0.4 (mole 2-MNPT/mole APU). Simple precipitation of APU particle by 2 N CaCl(2) recovered 95% of APU particle and 92% of 2-MNPT simultaneously. Also, 2-MNPT, which was entrapped inside the APU particle, was directly degraded by Acinetobacter sp. as same efficiency as without APU particle. These results showed the potentials of APU particle in the mobilization and biodegradation of hydrophobic compounds from soil.</P>

Hydrolysis of ammonia-pretreated sugar cane bagasse with cellulase, beta-glucosidase, and hemicellulase preparations.

Prior, Bernard A,Day, Donal F Humana Press ; Humana Press ; OCLC 2008 Applied biochemistry and biotechnology Vol.146 No.1

<P>Sugar cane bagasse consists of hemicellulose (24%) and cellulose (38%), and bioconversion of both fractions to ethanol should be considered for a viable process. We have evaluated the hydrolysis of pretreated bagasse with combinations of cellulase, beta-glucosidase, and hemicellulase. Ground bagasse was pretreated either by the AFEX process (2NH(3): 1 biomass, 100 degrees C, 30 min) or with NH(4)OH (0.5 g NH(4)OH of a 28% [v/v] per gram dry biomass; 160 degrees C, 60 min), and composition analysis showed that the glucan and xylan fractions remained largely intact. The enzyme activities of four commercial xylanase preparations and supernatants of four laboratory-grown fungi were determined and evaluated for their ability to boost xylan hydrolysis when added to cellulase and beta-glucosidase (10 filter paper units [FPU]: 20 cellobiase units [CBU]/g glucan). At 1% glucan loading, the commercial enzyme preparations (added at 10% or 50% levels of total protein in the enzyme preparations) boosted xylan and glucan hydrolysis in both pretreated bagasse samples. Xylanase addition at 10% protein level also improved hydrolysis of xylan and glucan fractions up to 10% glucan loading (28% solids loading). Significant xylanase activity in enzyme cocktails appears to be required for improving hydrolysis of both glucan and xylan fractions of ammonia pretreated sugar cane bagasse.</P>

Tagatose production with pH control in a stirred tank reactor containing immobilized L-arabinose rom Thermotoga neapolitana.

Lim, Byung-Chul,Kim, Hye-Jung,Oh, Deok-Kun Humana Press ; Humana Press ; OCLC 2008 Applied biochemistry and biotechnology Vol.149 No.3

<P>Chitopearl beads were used as immobilization supports for D-tagatose production from D-galactose by L-arabinose isomerase from Thermotoga neapolitana because chitopearl beads were more stable than alginate beads at temperatures above 60 degrees C. The pH and temperature for the maximum isomerization of galactose were 7.5 and 90 degrees C, respectively. In thermostability experiments, the half-lives of the immobilized enzyme at 70, 75, 80, 85, and 90 degrees C were 388, 106, 54, 36, and 22 h, respectively. The reaction temperature was determined to be 70 degrees C because the enzyme is highly stable up to 70 degrees C during the reaction. When the reaction time, galactose concentration, and temperature were increased, the pH of a mixture containing enzyme and galactose decreased by the Maillard reaction, resulting in decreased tagatose production. With pH control at 7.5, tagatose production (138 g/L) at 70 degrees C in a stirred tank reactor containing immobilized enzyme and 300 g/L galactose increased two times higher, comparing that without pH control.</P>

Statistical medium formulation and process modeling by mixture design of experiment for peptide overexpression in recombinant Escherichia coli.

Lee, Kwang-Min,Rhee, Chang-Hoon,Kang, Choong-Kyung,Kim, Jung-Hoe Humana Press ; Humana Press ; OCLC 2006 Applied biochemistry and biotechnology Vol.135 No.1

<P>The medium formulation and robust process modeling for anti-HIV peptide (T-20) production by recombinant Escherichia coli overexpression were studied by employing a crossed experimental design. The crossed design, a mixture design combined with process factor (induction duration), was used to find the optimal medium formulation and process time. The optimal settings for three major components (7.75 mL of NPK sources, 5.5 mL of glucose, and 11.75 mL of MgSO4) characterized by %T-20 (14.45%), the proportion of peptide to the total protein, were observed in a total of 100 mL of medium inducted at an optical density of 0.67 with 0.7 mM isopropyl-beta-D-thiogalactopyranoside) for a 3-h induction duration at shake-flask scale. These conditions were further investigated to find robust process conditions (8.2 mL of NPK sources, 5.6 mL of glucose, and 11.3 mL of MgSO4, and a 3.5-h induction duration time) for T-20 production (13.9%) by applying propagation of error.</P>

Cloning, overexpression, purification, and characterization of receptor-interacting protein 3 truncation in Escherichia coli.

Jeong, Mi Suk,Park, Jeong Soon,Jang, Se Bok Humana Press ; Humana Press ; OCLC 2007 Applied biochemistry and biotechnology Vol.141 No.2

<P>To facilitate structural studies of receptor-interacting protein 3 (RIP3), we developed a large-scale expression system of a glutathione-S-transferase (GST) fused with an 82 amino acid RIP3 protein in Escherichia coli. RIP3 truncation was subcloned into the pGEX-4T-1 vector and overexpressed in BL21(DE3)RIL cells. The soluble RIP3 protein was successfully purified to homogeneity using GST tag, an anion-exchange column, and gel filtration chromatography. The purity, identity, and conformation of the RIP3 protein were determined using sodium dodecyl sulfate polyacrylamide gel electrophoresis, Western blotting, matrix-assisted laser desorption ionization mass spectrometry, circular dichroism, and fluorescence spectroscopic studies. RIP3 showed dominance of the alpha-helix structure and temperature-dependent conformational change.</P>