Search results for: enzymatic conversion
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1534

Search results for: enzymatic conversion

1534 High Dissolution of ATC by pH Control and Its Enzymatic Conversion to L-Cysteine

Authors: Deokyeong Choe, Sung Hun Youn, Younggon Kim, Chul Soo Shin

Abstract:

L-Cysteine is extensively used as a supplement of pharmaceuticals, cosmetics, food and feed additives. It has obtained industrially by hydrolysis of human hair and poultry feathers. However, there are some problems such as the restriction of using materials from animals and the intractable waste pollution. The enzymatic conversion has been regarded as an environmental-friendly method. Currently, the biggest bottle-neck of enzymatic conversion is the low yield of L-cysteine due to the low substrate solubility. In this study, the method of enhancing the solubility of the substrate D,L-2-amino-Δ2-thiazoline-4-carboxylicacid (ATC) was developed and the enzymatic reaction at high concentration levels was performed. A large amount of substrate in aqueous solutions was dissolved by pH control using salts. As the pH of the solution increased, the solubility of ATC increased. It was thought that a shift of ATC from acid form (-COOH) to dissociated carboxylic group (-COO-) would improve its hydrophilicity leading to solubility increase. The highest solubility of ATC was 610 mM at pH 10.5, whereas the maximum reaction rate was obtained at pH 8.3. As a result, a high L-cysteine yield of 250 mM was achieved at pH 9.1, which was obtained from a combination of optimum pH conditions for ATC solubility and enzymatic conversion. This yield corresponds to approximately 18 times of that in previous reports.

Keywords: D, L-2-amino-Δ2-thiazoline-4-carboxylicacid, enzymatic conversion, high-substrate solubilization, L-Cysteine

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1533 Achievement of High L-Cysteine Yield from Enzymatic Conversion Using Eutectic Mixtures of the Substrate ATC

Authors: Deokyeong Choe, Sung Hun Youn, Younggon Kim, Chul Soo Shin

Abstract:

L-Cysteine, a sulfur-containing amino acid, has been often used in the pharmaceutical, cosmetic, food, and feed additive industries. This amino acid has been usually produced by acid-hydrolysis of human hair and poultry feathers. There are many problems, such as avoidance for use of animal hair, low yields, and formation of harmful waste material. As an alternative, the enzymatic conversion of D, L-2-amino-Δ2-thiazoline-4-carboxylic acid (ATC) to L-cysteine has been developed as an environmental-friendly method. However, the substrate solubility was too low to be used in industry. In this study, high concentrations of eutectic substrate solutions were prepared to solve the problem. Eutectic melting occurred at 39°C after mixing ATC and malonic acid at a molar ratio of 1:1. The characteristics of eutectic mixtures were analyzed by FE-SEM, EDS mapping, and XPS. However, since sorbitol, MnSO4, and NaOH should be added as supplements to the substrate mixture for the activation and stabilization of the enzyme, strategies for sequential addition of total five compounds, ATC, malonic acid, sorbitol, MnSO4, and NaOH were established. As a result, eutectic substrate mixtures of 670 mM ATC were successfully formulated. After 6 h of enzymatic reaction, 550 mM L-cysteine was made.

Keywords: D, L-2-amino-Δ2-thiazoline-4-carboxylicacid, enzymatic conversion, eutectic solution, l-cysteine

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1532 Enzymatic Saccharification of Dilute Alkaline Pre-treated Microalgal (Tetraselmis suecica) Biomass for Biobutanol Production

Authors: M. A. Kassim, R. Potumarthi, A. Tanksale, S. C. Srivatsa, S. Bhattacharya

Abstract:

Enzymatic saccharification of biomass for reducing sugar production is one of the crucial processes in biofuel production through biochemical conversion. In this study, enzymatic saccharification of dilute potassium hydroxide (KOH) pre-treated Tetraselmis suecica biomass was carried out by using cellulase enzyme obtained from Trichoderma longibrachiatum. Initially, the pre-treatment conditions were optimised by changing alkali reagent concentration, retention time for reaction, and temperature. The T. suecica biomass after pre-treatment was also characterized using Fourier Transform Infrared Spectra and Scanning Electron Microscope. These analyses revealed that the functional group such as acetyl and hydroxyl groups, structure and surface of T. suecica biomass were changed through pre-treatment, which is favourable for enzymatic saccharification process. Comparison of enzymatic saccharification of untreated and pre-treated microalgal biomass indicated that higher level of reducing sugar can be obtained from pre-treated T. suecica. Enzymatic saccharification of pre-treated T. suecica biomass was optimised by changing temperature, pH, and enzyme concentration to solid ratio ([E]/[S]). Highest conversion of carbohydrate into reducing sugar of 95% amounted to reducing sugar yield of 20 (wt%) from pre-treated T. suecica was obtained from saccharification, at temperature: 40°C, pH: 4.5 and [E]/[S] of 0.1 after 72 h of incubation. Hydrolysate obtained from enzymatic saccharification of pretreated T. suecica biomass was further fermented into biobutanol using Clostridium saccharoperbutyliticum as biocatalyst. The results from this study demonstrate a positive prospect of application of dilute alkaline pre-treatment to enhance enzymatic saccharification and biobutanol production from microalgal biomass.

Keywords: microalgal biomass, enzymatic saccharification, biobutanol, fermentation

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1531 Study of Individual Parameters on the Enzymatic Glycosidation of Betulinic Acid by Novozyme-435

Authors: A. U. Adamu, Hamisu Abdu, A. A. Saidu

Abstract:

The enzymatic synthesis of 3-O-β-D-glucopyranoside-betulinic acid using Novozyme-435 as a catalyst was studied. The effect of various parameters such as substrate molar ratio, reaction temperature, reaction time, re-used enzymes and amount of enzymes were investigated. The optimum rection conditions for the enzymatic glycosidation of betulinic acid in an organic solvent using Novozym-435 was found to be at 1:1.2 substrate molar ratio, 55oC, 24 h and 180 mg of enzymes with percentage conversion of 88.69 %.

Keywords: betulinic acid, glycosidation, novozyme-435, optimization

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1530 Enzymatic Esterification of Sardine Oil Processed in Morocco

Authors: M. Kharroubi, Y. Rady, F. Bellali, S. Himmi

Abstract:

The global objective of this study is to upgrade the sardine oil processed in Morocco by using enzymatic solutions. The specific objective of this part of study is to optimize the various parameters involved in enzymatic deacidification of fish oil processed in Morocco: pressure, ratio of oil/novozymes 435, ratio of oil/glycerol, temperature. The best deacidification yields were obtained with: -A temperature of 70 °C; -A ratio -Oil/Glycerol: 2% (% P); -A ratio -Oil/Novozyme 435: 1% (% P); -A pressure: 15 to 25 mbar. On the other hand, the study of the effect of initial oil acidity showed that whatever the acidity of the oil studied (very acidic, or low acidic), the final yields are high. Acidity does not reduce the reaction efficiency. From an industrial point of view, this represents a competitive advantage to consider. This eco-friend enzymatic solution may allows Moroccan fish oil producers to achieve acid number values that meet the standard.

Keywords: sardine oil, enzymatic esterfication, desacidification, acid number

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1529 Mathematical Modeling of Bi-Substrate Enzymatic Reactions in the Presence of Different Types of Inhibitors

Authors: Rafayel Azizyan, Valeri Arakelyan, Aram Gevorgyan, Varduhi Balayan, Emil Gevorgyan

Abstract:

Currently, mathematical and computer modeling are widely used in different biological studies to predict or assess behavior of such complex systems as biological ones. This study deals with mathematical and computer modeling of bi-substrate enzymatic reactions, which play an important role in different biochemical pathways. The main objective of this study is to represent the results from in silico investigation of bi-substrate enzymatic reactions in the presence of uncompetitive inhibitors, as well as to describe in details the inhibition effects. Four models of uncompetitive inhibition were designed using different software packages. Particularly, uncompetitive inhibitor to the first [ES1] and the second ([ES1S2]; [FS2]) enzyme-substrate complexes have been studied. The simulation, using the same kinetic parameters for all models allowed investigating the behavior of reactions as well as determined some interesting aspects concerning influence of different cases of uncompetitive inhibition. Besides that shown, that uncompetitive inhibitors exhibit specific selectivity depending on mechanism of bi-substrate enzymatic reaction.

Keywords: mathematical modeling, bi-substrate enzymatic reactions, reversible inhibition

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1528 Graphen-Based Nanocomposites for Glucose and Ethanol Enzymatic Biosensor Fabrication

Authors: Tesfaye Alamirew, Delele Worku, Solomon W. Fanta, Nigus Gabbiye

Abstract:

Recently graphen based nanocomposites are become an emerging research areas for fabrication of enzymatic biosensors due to their property of large surface area, conductivity and biocompatibility. This review summarizes recent research reports of graphen based nanocomposites for the fabrication of glucose and ethanol enzymatic biosensors. The newly fabricated enzyme free microwave treated nitrogen doped graphen (MN-d-GR) had provided highest sensitivity towards glucose and GCE/rGO/AuNPs/ADH composite had provided far highest sensitivity towards ethanol compared to other reported graphen based nanocomposites. The MWCNT/GO/GOx and GCE/ErGO/PTH/ADH nanocomposites had also enhanced wide linear range for glucose and ethanol detection respectively. Generally, graphen based nanocomposite enzymatic biosensors had fast direct electron transfer rate, highest sensitivity and wide linear detection ranges during glucose and ethanol sensing.

Keywords: glucose, ethanol, enzymatic biosensor, graphen, nanocomposite

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1527 Traditional Dyeing of Silk with Natural Dyes by Eco-Friendly Method

Authors: Samera Salimpour Abkenar

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In traditional dyeing of natural fibers with natural dyes, metal salts are commonly used to increase color stability. This method always carries the risk of environmental pollution (contamination of arable soils and fresh groundwater) due to the release of dyeing effluents containing large amounts of metal. Therefore, researchers are always looking for new methods to obtain a green dyeing system. In this research, the use of the enzymatic dyeing method to prevent environmental pollution with metals and reduce production costs has been proposed. After degumming and bleaching, raw silk fabrics were dyed with natural dyes (Madder and Sumac) by three methods (pre-mordanting with a metal salt, one-step enzymatic dyeing, and two-step enzymatic dyeing). Results show that silk dyed with natural dyes by the enzymatic method has higher color strength and colorfastness than the pretreated with a metal salt. Also, the amount of remained dyes in the dyeing wastewater is significantly reduced by the enzymatic method. It is found that the enzymatic dyeing method leads to improvement of dye absorption, color strength, soft hand, no change in color shade, low production costs (due to low dyeing temperature), and a significant reduction in environmental pollution.

Keywords: eco-friendly, natural dyes, silk, traditional dyeing

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1526 Effect of Different Microbial Strains on Biological Pretreatment of Sugarcane Bagasse for Enzymatic Hydrolysis

Authors: Achiraya Jiraprasertwong, Erdogan Gulari, Sumaeth Chavadej

Abstract:

Among agricultural residues, sugarcane bagasse is one of the most convincing raw materials for the production of bioethanol due to its availability, and low cost through enzymatic hydrolysis and yeast fermentation. A pretreatment step is needed to enhance the enzymatic step. In this study, sugarcane bagasse (SCB), one of the most abundant agricultural residues in Thailand, was pretreated biologically with various microorganisms of white-rot fungus—Phanerochaete sordid (SK 7), Cellulomonas sp. (TISTR 784), and strain A 002 (Bacillus subtilis isolated from Thai higher termites). All samples with various microbial pretreatments were further hydrolyzed enzymatically by a commercial enzyme obtained from Aspergillus niger. The results showed that the pretreatment with the white-rot fungus gave the highest glucose concentration around two-fold higher when compared with the others.

Keywords: sugarcane bagasse, microorganisms, pretreatment, enzymatic hydrolysis

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1525 Effects of Palm Kernel Expeller Processing on the Ileal Populations of Lactobacilli and Escherichia Coli in Broiler Chickens

Authors: B. Navidshad

Abstract:

The main objective of this study was to examine the effects of enzymatic treatment and shell content of palm kernel expeller (PKE) on the ileal Lactobacilli and Escherichia coli populations in broiler chickens. At the finisher phase, one hundred male broiler chickens (Cobb-500) were fed a control diet or the diets containing 200 g/kg of normal PKE (70 g/kg shell), low shell PKE (30 g/kg shell), enzymatic treated PKE or low shell-enzymatic treated PKE. The quantitative real-time PCR were used to determine the ileal bacteria populations. The lowest ileal Lactobacilli population was found in the chickens fed the low shell PKE diet. Dietary normal PKE or low shell-enzymatic treated PKE decreased the Escherichia coli population compared to the control diet. The results suggested that PKE could be included up to 200 g/kg in the finisher diet, however, any screening practice to reduce the shell content of PKE without enzymatic degradation of β-mannan, decrease ileal Lactobacilli population.

Keywords: palm kernel expeller, exogenous enzyme, shell content, ileum bacteria, broiler chickens

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1524 Study on the Efficiency of Some Antioxidants on Reduction of Maillard Reaction in Low Lactose Milk

Authors: Farnaz Alaeimoghadam, Farzad Alaeimoghadam

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In low-lactose milk, due to lactose hydrolysis and its conversion to monosaccharides like glucose and galactose, the Maillard reaction (non-enzymatic browning) occurs more readily compared to non-hydrolyzed milk. This reaction incurs off-flavor and dark color, as well as a decrease in the nutritional value of milk. The target of this research was to evaluate the effect of natural antioxidants in diminishing the browning in low-lactose milk. In this research, three antioxidants, namely ascorbic acid, gallic acid, and pantothenic acid in the concentration range of 0-1 mM/L, either in combination with each other or separately, were added to low-lactose milk. After heat treatment (120 0C for 3 min.), milk samples incubated at 55 0C for one day and then stored at 4 0C for 9 days. Quality indices, including total phenol content, antioxidant activity, color indices, and sensory characters, were measured during intervals of 0, 2, 5, 7, and 9 days. Results of this research showed that the effect of storage time and adding antioxidants were significant on pH, antioxidant activity, total phenolic compounds either before or after heating, index L*, color change, and sensational characteristics (p < 0.05); however, acidity, a* and b* indices, chroma, and hue angle showed no significant changes (p > 0.05). The findings showed that the simultaneous application of gallic acid and ascorbic in the diminishing of non-enzymatic browning and color change, increasing pH, longevity, and antioxidant activity after heat treatment, and augmenting phenolic compounds before heat treatment was better than that of pantothenic acid.

Keywords: Maillard, low-lactose milk, non-enzymatic browning, natural antioxidant

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1523 Optimization and Kinetic Analysis of the Enzymatic Hydrolysis of Oil Palm Empty Fruit Bunch To Xylose Using Crude Xylanase from Trichoderma Viride ITB CC L.67

Authors: Efri Mardawati, Ronny Purwadi, Made Tri Ari Penia Kresnowati, Tjandra Setiadi

Abstract:

EFB are mainly composed of cellulose (≈ 43%), hemicellulose (≈ 23%) and lignin (≈20%). The palm oil empty fruit bunches (EFB) is the lignosellulosic waste from crude palm oil industries mainly compose of (≈ 43%), hemicellulose (≈ 23%) and lignin (≈20%). Xylan, a polymer made of pentose sugar xylose and the most abundant component of hemicellulose in plant cell wall. Further xylose can be used as a raw material for production of a wide variety of chemicals such as xylitol, which is extensively used in food, pharmaceutical and thin coating applications. Currently, xylose is mostly produced from xylan via chemical hydrolysis processes. However, these processes are normally conducted at a high temperature and pressure, which is costly, and the required downstream processes are relatively complex. As an alternative method, enzymatic hydrolysis of xylan to xylose offers an environmentally friendly biotechnological process, which is performed at ambient temperature and pressure with high specificity and at low cost. This process is catalysed by xylanolytic enzymes that can be produced by some fungal species such as Aspergillus niger, Penicillium crysogenum, Tricoderma reseei, etc. Fungal that will be used to produce crude xylanase enzyme in this study is T. Viride ITB CC L.67. It is the purposes of this research to study the influence of pretreatment of EFB for the enzymatic hydrolysis process, optimation of temperature and pH of the hydrolysis process, the influence of substrate and enzyme concentration to the enzymatic hydrolysis process, the dynamics of hydrolysis process and followingly to study the kinetics of this process. Xylose as the product of enzymatic hydrolysis process analyzed by HPLC. The results show that the thermal pretreatment of EFB enhance the enzymatic hydrolysis process. The enzymatic hydrolysis can be well approached by the Michaelis Menten kinetic model, and kinetic parameters are obtained from experimental data.

Keywords: oil palm empty fruit bunches (EFB), xylose, enzymatic hydrolysis, kinetic modelling

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1522 In-Silico Fusion of Bacillus Licheniformis Chitin Deacetylase with Chitin Binding Domains from Chitinases

Authors: Keyur Raval, Steffen Krohn, Bruno Moerschbacher

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Chitin, the biopolymer of the N-acetylglucosamine, is the most abundant biopolymer on the planet after cellulose. Industrially, chitin is isolated and purified from the shell residues of shrimps. A deacetylated derivative of chitin i.e. chitosan has more market value and applications owing to it solubility and overall cationic charge compared to the parent polymer. This deacetylation on an industrial scale is performed chemically using alkalis like sodium hydroxide. This reaction not only is hazardous to the environment owing to negative impact on the marine ecosystem. A greener option to this process is the enzymatic process. In nature, the naïve chitin is converted to chitosan by chitin deacetylase (CDA). This enzymatic conversion on the industrial scale is however hampered by the crystallinity of chitin. Thus, this enzymatic action requires the substrate i.e. chitin to be soluble which is technically difficult and an energy consuming process. We in this project wanted to address this shortcoming of CDA. In lieu of this, we have modeled a fusion protein with CDA and an auxiliary protein. The main interest being to increase the accessibility of the enzyme towards crystalline chitin. A similar fusion work with chitinases had improved the catalytic ability towards insoluble chitin. In the first step, suitable partners were searched through the protein data bank (PDB) wherein the domain architecture were sought. The next step was to create the models of the fused product using various in silico techniques. The models were created by MODELLER and evaluated for properties such as the energy or the impairment of the binding sites. A fusion PCR has been designed based on the linker sequences generated by MODELLER and would be tested for its activity towards insoluble chitin.

Keywords: chitin deacetylase, modeling, chitin binding domain, chitinases

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1521 Study on Microbial Pretreatment for Enhancing Enzymatic Hydrolysis of Corncob

Authors: Kessara Seneesrisakul, Erdogan Gulari, Sumaeth Chavadej

Abstract:

The complex structure of lignocellulose leads to great difficulties in converting it to fermentable sugars for the ethanol production. The major hydrolysis impediments are the crystallinity of cellulose and the lignin content. To improve the efficiency of enzymatic hydrolysis, microbial pretreatment of corncob was investigated using two bacterial strains of Bacillus subtilis A 002 and Cellulomonas sp. TISTR 784 (expected to break open the crystalline part of cellulose) and lignin-degrading fungus, Phanerochaete sordida SK7 (expected to remove lignin from lignocellulose). The microbial pretreatment was carried out with each strain under its optimum conditions. The pretreated corncob samples were further hydrolyzed to produce reducing glucose with low amounts of commercial cellulase (25 U•g-1 corncob) from Aspergillus niger. The corncob samples were determined for composition change by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscope (SEM). According to the results, the microbial pretreatment with fungus, P. sordida SK7 was the most effective for enhancing enzymatic hydrolysis, approximately, 40% improvement.

Keywords: corncob, enzymatic hydrolysis, glucose, microbial pretreatment

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1520 Fermentation of Wood Waste by Treating with H₃PO₄-Acetone for Bioethanol Production

Authors: Deokyeong Choe, Keonwook Nam, Young Hoon Roh

Abstract:

Wood waste is a potentially significant resource for economic and environment-friendly recycling. Wood waste represents a key sustainable source of biomass for transformation into bioethanol. Unfortunately, wood waste is highly recalcitrant for biotransformation, which limits its use and prevents economically viable conversion into bioethanol. As a result, an effective pretreatment is necessary to degrade cellulose of the wood waste, which improves the accessibility of cellulase. In this work, a H₃PO₄-acetone pretreatment was selected among the various pretreatment methods and used to dissolve cellulose and lignin. When the H₃PO₄ and acetone were used, 5–6% of the wood waste was found to be very appropriate for saccharification. Also, when the enzymatic saccharification was conducted in the mixture of the wood waste and 0.05 M citrate buffer solution, glucose and xylose were measured to be 80.2 g/L and 9.2 g/L respectively. Furthermore, ethanol obtained after 70 h of fermentation by S. cerevisiae was 30.4 g/L. As a result, the conversion yield from wood waste to bioethanol was calculated to be 57.4%. These results show that the pretreated wood waste can be used as good feedstocks for bioethanol production and that the H₃PO₄-acetone pretreatment can effectively increase the yield of ethanol production.

Keywords: wood waste, H₃PO₄-acetone, bioethanol, fermentation

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1519 Production of Antimicrobial Agents against Multidrug-Resistant Staphylococcus aureus through the Biocatalysis of Vegetable Oils

Authors: Hak-Ryul Kim, Hyung-Geun Lee, Qi Long, Ching Hou

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Structural modification of natural lipids via chemical reaction or microbial bioconversion can change their properties or even create novel functionalities. Enzymatic oxidation of lipids leading to formation of oxylipin is one of those modifications. Hydroxy fatty acids, one of those oxylipins have gained important attentions because of their structural and functional properties compared with other non-hydroxy fatty acids. Recently 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) was produced with high yield from lipid-containing oleic acid by microbial conversion, and the further study confirmed that DOD contained strong antimicrobial activities against a broad range of microorganisms. In this study, we tried to modify DOD molecules by the enzymatic or physical reaction to create new functionality or to enhance the antimicrobial activity of DOD. After modification of DOD molecules by different ways, we confirmed that the antimicrobial activity of DOD was highly enhanced and presented strong antimicrobial activities against multidrug-resistant Staphylococcus aureus, suggesting that DOD and its derivatives can be used as efficient antimicrobial agents for medical and industrial applications.

Keywords: biocatalysis, antimicrobial agent, multidrug-resistant bacteria, vegetable oil

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1518 Explicable Enzymatic Mechanism of H-Ido to Oxidise Tryptophan by Employing Various Substrates

Authors: Ali Bahri Lubis

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The study of dioxygenase enzymatic mechanism on tryptophan oxidation has been a wide interest since the reaction is rate-limiting step of kynurenine pathway. In this research, observation of tryptophan oxidation through h-IDO enzyme along with synthesis of enzyme products was conducted in order to comprehend how the enzyme works on distinct substrates. UV-vis spectrophotometry, LC-MS, H-NMR and HSQC measurement were carried out to characterise enzyme product. It is found that while tryptophan was oxidised to form Nformylkynurenine (NFK) as a major product and hydroxypyrroloindole amine carboxylic acid (HPIC) in cis and trans confirmed in HSQC, N-methyl tryptophan substrate was converted to NFK and trans HPIC only. Other intriguing results showed that 5-hydroxy- tryptophan and Stryptophan was degraded to become NFK and epoxide cyclic respectively. The formation of NFK was considered through dioxygenation pathway, however HPIC was formed via monooxygenation. The epoxide cyclic—considered as intermediate compound in the mechanism— from S-tryptophan was not able to cleave the epoxide ring since bond energy of epoxide was probably much stronger. This validates the enzymatic mechanism where the intermediate compound in the enzymatic mechanism is epoxide cyclic.

Keywords: tryptophan oxidation, heme-dioxygenases, N-formylkynurenine, hydroxypyrrroloindoleamine, monooxidation

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1517 Conversion of HVAC Lines into HVDC in Transmission Expansion Planning

Authors: Juan P. Novoa, Mario A. Rios

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This paper presents a transmission planning methodology that considers the conversion of HVAC transmission lines to HVDC as an alternative of expansion of power systems, as a consequence of restrictions for the construction of new lines. The transmission expansion planning problem formulates an optimization problem that minimizes the total cost that includes the investment cost to convert lines from HVAC to HVDC and possible required reinforcements of the power system prior to the conversion. The costs analysis assesses the impact of the conversion on the reliability because transmission lines are out of service during the conversion work. The presented methodology is applied to a test system considering a planning a horizon of 10 years.

Keywords: transmission expansion planning, HVDC, cost optimization, energy non-supplied

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1516 The Thermochemical Conversion of Lactic Acid in Subcritical and Supercritical Water

Authors: Shyh-Ming Chern, Hung-Chi Tu

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One way to utilize biomass is to thermochemically convert it into gases and chemicals. For conversion of biomass, glucose is a particularly popular model compound for cellulose, or more generally for biomass. The present study takes a different approach by employing lactic acid as the model compound for cellulose. Since lactic acid and glucose have identical elemental composition, they are expected to produce similar results as they go through the conversion process. In the current study, lactic acid was thermochemically converted to assess its reactivity and reaction mechanism in subcritical and supercritical water, by using a 16-ml autoclave reactor. The major operating parameters investigated include: The reaction temperature, from 673 to 873 K, the reaction pressure, 10 and 25 MPa, the dosage of oxidizing agent, 0 and 0.5 chemical oxygen demand, and the concentration of lactic acid in the feed, 0.5 and 1.0 M. Gaseous products from the conversion were generally found to be comparable to those derived from the conversion of glucose.

Keywords: lactic acid, subcritical water, supercritical water, thermochemical conversion

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1515 Enzymatic Biomonitoring of Aquatic Pollution at Jeddah Southern Red Sea Shore

Authors: Saleh Mohamed, Mohamed El-Shal, Taha Kumosani, Ahmad Mal, Youssri Ahmed, Yasser Almulaiky

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The marine environment of the Jeddah southern red sea shore is subjected to increasing anthropogenic activities as sewage sludge draining and desalting processes. The objective of this study is to compare the quantitative responses of enzymatic biomarkers in fish from polluted area with the responses of organism from reference area. Enzymatic biomarkers as neurotoxic, antioxidant and detoxifying enzymes were evaluated in the brain and liver from Variola louti as a sentinel species sampled from both polluted and reference sites in the Jeddah southern red sea shore during four months January, April, July and October in 2014 and 2015. In brain of V. louti, the activity of acetylcholinestease (AChE) collected from reference area significantly increased 8.8 and 10.5 folds than that from polluted area in 2014 and 2015, respectively. The activities of catalase (CAT), glutathione reductase (GR) and glutathione peroxidase (GPx) and glutathione-S-transferase (GST) from liver of V. louti in polluted area significantly increased 1.4, 1.27 and 3, 4.5 and 4.37, 2 and 5, 4.5 folds than that from reference area in 2014 and 2015, respectively. The levels of examined enzymes are approximately similar in the four seasons detected in 2014 and 2015 indicating that the similar components of sewage were draining in red sea. In conclusion, these findings suggest the important of enzymatic biomarkers in monitoring the pollution in Jeddah red sea shore.

Keywords: Variola louti, enzymatic biomarkers, pollution, Red sea

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1514 Enzymatic Remediation in Standard Crude Palm Oil for Superior Quality Oil

Authors: Haniza Ahmad, Norliza Saparin, Ahmadilfitri Md Noor, Mohd Suria Affandi Yusoff

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Enzymatic remediation is applied in low free fatty acid (FFA) (<4%) crude palm oil (CPO) to investigate if further FFA reduction is able to take place to produce premium CPO (<1% FFA). There are four different lipase Candida Antartica brands used in this study. Samples submit to enzymatic remediation using rotary evaporator under 100mbar vacuum with rotation at 260rpm. Samples were taken at 4hours, 8hours and 24hours for analyses. FFA less than 1% was achieved after 24hours reaction with 1% enzyme and 2% glycerol. The FFA reduction was intensified with the presence of glycerol who provides more sites for fatty acid attachment. At 2% glycerol, 71-88% FFA was reduced whereas at 1% glycerol, 46-75% FFA reduced. However, partial glycerides was increased with presence of glycerol with 2% add in glycerol showed greater partial glycerides increment compared to 1% glycerol.

Keywords: enzymes, crude palm oil, free fatty acid, glycerol

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1513 Optimization of Alkali Assisted Microwave Pretreatments of Sorghum Straw for Efficient Bioethanol Production

Authors: Bahiru Tsegaye, Chandrajit Balomajumder, Partha Roy

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The limited supply and related negative environmental consequence of fossil fuels are driving researcher for finding sustainable sources of energy. Lignocellulose biomass like sorghum straw is considered as among cheap, renewable and abundantly available sources of energy. However, lignocellulose biomass conversion to bioenergy like bioethanol is hindered due to the reluctant nature of lignin in the biomass. Therefore, removal of lignin is a vital step for lignocellulose conversion to renewable energy. The aim of this study is to optimize microwave pretreatment conditions using design expert software to remove lignin and to release maximum possible polysaccharides from sorghum straw for efficient hydrolysis and fermentation process. Sodium hydroxide concentration between 0.5-1.5%, v/v, pretreatment time from 5-25 minutes and pretreatment temperature from 120-2000C were considered to depolymerize sorghum straw. The effect of pretreatment was studied by analyzing the compositional changes before and after pretreatments following renewable energy laboratory procedure. Analysis of variance (ANOVA) was used to test the significance of the model used for optimization. About 32.8%-48.27% of hemicellulose solubilization, 53% -82.62% of cellulose release, and 49.25% to 78.29% lignin solubilization were observed during microwave pretreatment. Pretreatment for 10 minutes with alkali concentration of 1.5% and temperature of 1400C released maximum cellulose and lignin. At this optimal condition, maximum of 82.62% of cellulose release and 78.29% of lignin removal was achieved. Sorghum straw at optimal pretreatment condition was subjected to enzymatic hydrolysis and fermentation. The efficiency of hydrolysis was measured by analyzing reducing sugars by 3, 5 dinitrisylicylic acid method. Reducing sugars of about 619 mg/g of sorghum straw were obtained after enzymatic hydrolysis. This study showed a significant amount of lignin removal and cellulose release at optimal condition. This enhances the yield of reducing sugars as well as ethanol yield. The study demonstrates the potential of microwave pretreatments for enhancing bioethanol yield from sorghum straw.

Keywords: cellulose, hydrolysis, lignocellulose, optimization

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1512 Conversion in Islam: The Case of Iranian Converts to Christianity in Malaysia

Authors: Gholamreza Nuei, Faisal Ahmad Shah

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The way religion defines people’s identity is quite important in the majority of Muslim countries. Yet, in most such countries the number of Muslims converting to other religions is not documented. The present research investigates a population of Iranians who have converted to Christianity and live in Malaysia. This article focuses on this subgroup of ex-Muslims with the aim of providing a window into how they experience and justify their conversion. The data was collected in Kuala Lumpur, Malaysia. It was carried out through in-depth interviews with 13 people; also 45 people answered a questionnaire (quantitative). The research findings revealed some of the typical religious, social and personal reasons behind the conversion of this group of "ex-Muslims".

Keywords: conversion from Islam to Christianity, apostasy, Iran, Malaysia

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1511 Ambiguity in Anti-conversion Laws in the Indian States – A Limitation to the Freedom of Religion Guaranteed under the Constitution of India

Authors: Roy Alex, Dr. Shampa I Dev

Abstract:

Abstract Nine out of twenty-eight states in India have enacted anti-conversion laws to regulate religious conversions by use of force, allurement, inducement, or fraudulent means. The vagueness of the definitions of the terms used in these laws makes them inconsistent with the provisions of the right to freedom of religion guaranteed by the Constitution. It is a critical question whether these laws protect the religious freedom of groups that are “vulnerable” to missionary inducements, or are they restricting the freedom of citizens to propagate their religion to others or change their religious identity? This article looks into the constitutionality of the anti-conversion laws passed in the Indian States and argues that these laws limit the freedom of religion guaranteed under Article 25 of the Constitution of India. The ambiguity in the anti-conversion laws passed in various states of India is brought out by critically analyzing multiple cases charged under anti-conversion laws.

Keywords: Freedom of Religion, Anti-conversion Laws, allurement, inducement, and fraudulent means.

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1510 Influence of Moss Cover and Seasonality on Soil Microbial Biomass and Enzymatic Activity in Different Central Himalayan Temperate Forest Types

Authors: Anshu Siwach, Qianlai Zhuang, Ratul Baishya

Abstract:

Context: This study focuses on the influence of moss cover and seasonality on soil microbial biomass and enzymatic activity in different Central Himalayan temperate forest types. Soil microbial biomass and enzymes are key indicators of microbial communities in soil and provide information on soil properties, microbial status, and organic matter dynamics. The activity of microorganisms in the soil varies depending on the vegetation type and environmental conditions. Therefore, this study aims to assess the effects of moss cover, seasons, and different forest types on soil microbial biomass carbon (SMBC), soil microbial biomass nitrogen (SMBN), and soil enzymatic activity in the Central Himalayas, Uttarakhand, India. Research Aim: The aim of this study is to evaluate the levels of SMBC, SMBN, and soil enzymatic activity in different temperate forest types under the influence of two ground covers (soil with and without moss cover) during the rainy and winter seasons. Question Addressed: This study addresses the following questions: 1. How does the presence of moss cover and seasonality affect soil microbial biomass and enzymatic activity? 2. What is the influence of different forest types on SMBC, SMBN, and enzymatic activity? Methodology: Soil samples were collected from different forest types during the rainy and winter seasons. The study utilizes the chloroform-fumigation extraction method to determine SMBC and SMBN. Standard methodologies are followed to measure enzymatic activities, including dehydrogenase, acid phosphatase, aryl sulfatase, β-glucosidase, phenol oxidase, and urease. Findings: The study reveals significant variations in SMBC, SMBN, and enzymatic activity under different ground covers, within the rainy and winter seasons, and among the forest types. Moss cover positively influences SMBC and enzymatic activity during the rainy season, while soil without moss cover shows higher values during the winter season. Quercus-dominated forests, as well as Cupressus torulosa forests, exhibit higher levels of SMBC and enzymatic activity, while Pinus roxburghii forests show lower levels. Theoretical Importance: The findings highlight the importance of considering mosses in forest management plans to improve soil microbial diversity, enzymatic activity, soil quality, and health. Additionally, this research contributes to understanding the role of lower plants, such as mosses, in influencing ecosystem dynamics. Conclusion: The study concludes that moss cover during the rainy season significantly influences soil microbial biomass and enzymatic activity. Quercus and Cupressus torulosa dominated forests demonstrate higher levels of SMBC and enzymatic activity, indicating the importance of these forest types in sustaining soil microbial diversity and soil health. Including mosses in forest management plans can improve soil quality and overall ecosystem dynamics.

Keywords: moss cover, seasons, soil enzymes, soil microbial biomass, temperate forest types

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1509 Effect of Cellulase Pretreatment for n-Hexane Extraction of Oil from Garden Cress Seeds

Authors: Boutemak Khalida, Dahmani Siham

Abstract:

Garden cress (Lepidium Sativum L.) belonging to the family Brassicaceae, is edible growing annual herb. Its various parts (roots, leaves and seeds) have been used to treat various human ailments. Its seed extracts have been screened for various biological activities like hypotensive, antimicrobial, bronchodilator, hypoglycaemic and antianemic. The aim of the present study is to optimize the process parameters (cellulase concentration and incubation time) of enzymatic pre-treatment of the garden cress seeds and to evaluate the effect of cellulase pre-treatment of the crushed seeds on the oil yield, physico-chemical properties and antibacterial activity and comparing to non-enzymatic method. The optimum parameters of cellulase pre-treatment were as follows: cellulase of 0,1% w/w and incubation time of 2h. After enzymatic pre-treatment, the oil was extracted by n-hexane for 1.5 h, the oil yield was 4,01% for cellulase pre-treatment as against 10,99% in the control sample. The decrease in yield might be caused a result of mucilage. Garden cress seeds are covered with a layer of mucilage which gels on contact with water. At the same time, the antibacterial activity was carried out using agar diffusion method against 4 food-borne pathogens (Escherichia coli, Salmonella typhi,Staphylococcus aureus, Bacillus subtilis). The results showed that bacterial strains are very sensitive to the oil with cellulase pre-treatment. Staphylococcus aureus is extremely sensitive with the largest zone of inhibition (40 mm), Escherichia coli and salmonella typhi had a very sensitive to the oil with a zone of inhibition (26 mm). Bacillus subtilizes is averagely sensitive which gave an inhibition of 16 mm. But it does not exhibit sensivity to the oil without enzymatic pre-treatment with a zone inhibition (< 8 mm). Enzymatic pre-treatment could be useful for antimicrobial activity of the oil, and hold a good potential for use in food and pharmaceutical industries.

Keywords: Lepidium sativum L., cellulase, enzymatic pretreatment, antibacterial activity.

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1508 Wavelength Conversion of Dispersion Managed Solitons at 100 Gbps through Semiconductor Optical Amplifier

Authors: Kadam Bhambri, Neena Gupta

Abstract:

All optical wavelength conversion is essential in present day optical networks for transparent interoperability, contention resolution, and wavelength routing. The incorporation of all optical wavelength convertors leads to better utilization of the network resources and hence improves the efficiency of optical networks. Wavelength convertors that can work with Dispersion Managed (DM) solitons are attractive due to their superior transmission capabilities. In this paper, wavelength conversion for dispersion managed soliton signals was demonstrated at 100 Gbps through semiconductor optical amplifier and an optical filter. The wavelength conversion was achieved for a 1550 nm input signal to1555nm output signal. The output signal was measured in terms of BER, Q factor and system margin.    

Keywords: all optical wavelength conversion, dispersion managed solitons, semiconductor optical amplifier, cross gain modultation

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1507 Effect of Enzymatic Modification on the Crystallinity of Cellulose Pulps

Authors: J. Janicki, M. Rom, C. Slusarczyk, J. Fabia, M. Siika-aho, K. Marjamaa, K. Kruus, K. Langfelder, C. Steel, M. Paloheimo, T. Puranen, S. Mäkinen, D. Wawro

Abstract:

The cellulose is one of the most abundant polymers in the world, however, its application in the high-end value products such as films or fibres, it triggered by the cellulose properties. The noticeable presence of hydrogen bonding reflected with partially crystalline structure makes the cellulose insoluble in common solvents and not meltable. The existing technologies, such as viscose process, suffer from environmental and economical problems, because of the risk of harmful chemicals liberation during the spinning process. The enzymatic modification of cellulose with endoglucanase makes it directly alkali soluble in NaOH solution, giving the opportunities for film and fibers formation. As the effect of enzymatic treatment, there are observed changes in crystalline structure and accompanying changes of the affinity of cellulose to water, demonstrated by water retention value. The objective of the project ELMO - Novel carbohydrate modifying enzymes for fibre modification is is to develop new enzyme products for modification of dissolving grade pulps. The aim is to increase the reactivity of dissolving grade pulps and remove residual hemicellulose. The scientific aim of this paper is to present the effect of enzymatic treatment on the crystallinity and affinity to water of cellulose pulps modified with enzymes.

Keywords: cellulose, crystallinity, WAXS, enzyme

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1506 Enhance Biogas Production by Enzymatic Pre-Treatment from Palm Oil Mill Effluent (POME)

Authors: M. S. Tajul Islam, Md. Zahangir Alam

Abstract:

To enhance biogas production through anaerobic digestion, the application of various type of pre-treatment method has some limitations in terms of sustainable environmental management. Many studies on pretreatments especially chemical and physical processes are carried out to evaluate the anaerobic digestion for enhanced biogas production. Among the pretreatment methods acid and alkali pre-treatments gained the highest importance. Previous studies have showed that although acid and alkali pretreatment has significant effect on degradation of biomass, these methods have some negative impact on environment due to their hazard in nature while enzymatic pre-treatment is environmentally friendly. One of the constrains to use of enzyme in pretreatment process for biogas production is high cost which is currently focused to reduce cost through fermentation of waste-based media. As such palm oil mill effluent (POME) as an abundant resource generated during palm oil processing at mill is being used a potential fermentation media for enzyme production. This low cost of enzyme could be an alternative to biogas pretreatment process. This review is to focus direct application of enzyme as enzymatic pre-treatment on POME to enhanced production of biogas.

Keywords: POME, enzymatic pre-treatment, biogas, lignocellulosic biomass, anaerobic digestion

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1505 Influence of Preheating Self-Adhesive Cements on the Degree of Conversion, Cell Migration and Cell Viability in NIH/3T3

Authors: Celso Afonso Klein Jr., Henrique Cantarelli, Fernando Portella, Keiichi Hosaka, Eduardo Reston, Fabricio Collares, Roberto Zimmer

Abstract:

TTo evaluate the influence of preheating self-adhesive cement at 39ºC on cell migration, cytotoxicity and degree of conversion. RelyX U200, Set PP and MaxCem Elite were subjected to a degree of conversion analysis (FTIR-ATR). For the cytotoxicity analysis, extracts (24 h and 7 days) were placed in contact with NIH/3T3 cells. For cell migration, images were captured of each sample until the possible closure of the cleft occurred. In the results of the degree of conversion, preheating did not improve the conversion of cement. For the MTT, preheating did not improve the results within 24 hours. However, it generated positive results within 7 days for the Set PP resin cement. For cell migration, high rates of cell death were found in all groups. It is concluded that preheating at 39ºC caused a positive effect only in increasing the cell viability of the Set PP resin cement and that both materials analyzed are highly cytotoxic.

Keywords: dental cements, resin cements, degree of conversion, cytotoxicity, cell migration assays

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