The transient kinetic behavior of enzyme reactions prior to the establishment of steady state is a major source of mechanistic information. Yet, this approach has not been utilized for cellulases acting on their natural substrate, insoluble cellulose. Here, we elucidate the pre-steady state regime for the exo-acting cellulase Cel7A using ...

Cellulase, Tween 80, and β-glucosidase loading were studied and optimized by response surface methodology to improve saccharification. Microwave alkali-pretreated rice straw used as substrate for onsite enzyme production by Aspergillus heteromorphus and Trichoderma reesei. The highest enzymatic hydrolysis (84%) was obtained from rice straw at crude enzyme loading of 10 FPU/gds ...

One of the drawbacks of nonaqueous enzymology is the fact that enzymes tend to be less stable in organic solvents than in water. There are, however, some enzymes that display very high stabilities in nonaqueous media. In order to take full advantage of the use of nonaqueous solvents in enzyme ...

Use of Trichoderma reesei RT-P1 crude enzyme powder and of this powder with 10%v/v Saccharomyces cerevisiae for ethanol fermentation of sweet sorghum fresh stalks were investigated. The optimal conditions were determined by orthogonal experiment method. With T. reesei crude enzyme powder, the optimal condition for the Keller cultivar was at ...

Consolidated bioprocessing, or CBP, the conversion of lignocellulose into desired products in one step without added enzymes, has been a subject of increased research effort in recent years. In this review, the economic motivation for CBP is addressed, advances and remaining obstacles for CBP organism development are reviewed, and we ...

The effect of several water-miscible cosolvents on activity and stability of soluble and immobilized 2'-deoxyribosyltransferase from Lactobacillus reuteri on Sepabeads® has been studied in order to establish optimal conditions for enzymatic synthesis of nucleosides using purine bases with low solubility in aqueous buffer. As a rule of thumb, there was ...

In this work, laccase enzymes were evaluated to detoxify the whole slurry from steam-exploded wheat straw. For it, two different strategies, laccase treatment before or after enzymatic hydrolysis, were employed. The detoxification efficiency was analyzed on enzymatic hydrolysis and fermentation levels by the thermotolerant yeast Kluyveromyces marxianus. Laccases reduced phenolic ...

Alkaline hydrogen peroxide (AHP) has several attractive features as a pretreatment in the lignocellulosic biomass-to-ethanol pipeline. Here, the feasibility of scaling-up the AHP process and integrating it with enzymatic hydrolysis and fermentation was studied. Corn stover (1 kg) was subjected to AHP pretreatment, hydrolyzed enzymatically, and the resulting sugars fermented to ...

This research was performed to investigate in vitro the biological activities of successive as well as 70% ethanol extracts of Nepeta cataria on some biochemical parameters including oxidative markers and carbohydrate-hydrolysing enzyme activities (α-amylase, β-galactosidase and α-glucosidase). Powdered N. cataria and its successive extracts were screened for their phytochemical constituents. Tests ...

With the aim of understanding the contribution of enzymes to the cost of lignocellulosic biofuels, we constructed a technoeconomic model for the production of fungal cellulases. We found that the cost of producing enzymes was much higher than that commonly assumed in the literature. For example, the cost contribution of ...

Cassava is a starch-containing root crop that is widely used as a raw material in a variety of industrial applications, most recently in the production of fuel ethanol. In the present study, ethanol production from raw (uncooked) cassava flour by simultaneous saccharification and fermentation (SSF) using a preparation consisting of ...

This study reports a new yeast strain of Clavispora NRRL Y-50464 that is able to utilize cellobiose as sole source of carbon and produce sufficient native β-glucosidase enzyme activity for cellulosic ethanol production using SSF. In addition, this yeast is tolerant to the major inhibitors derived from lignocellulosic biomass pre-treatment ...

This study was carried out to investigate the anti-fertility and anti-venom activities of the extract of the stem bark of Butea monosperma by inhibiting hyaluronidase, which is a spreading factor and plays a role in fertilisation. Among ethanol, methanol and water extracts, the ethanol extract dose-dependently inhibited the ovine, mouse ...

The ethanol production capacity from sugars and lignocellulosic biomass hydrolysates by Thermoanaerobacterium strain AK(17) was studied in batch cultures. The strain converts various carbohydrates to, acetate, ethanol, hydrogen and carbon dioxide. Ethanol yields on glucose and xylose were 1.5 and 1.1 mol/mol sugars, respectively. Increased initial glucose concentration inhibited glucose degradation ...

An alternative route for bio-ethanol production from sugarcane stalks (juice and bagasse) featuring a previously reported low temperature alkali pretreatment method was evaluated. Test-tube scale pretreatment-saccharification experiments were carried out to determine optimal LTA pretreatment conditions for sugarcane bagasse with regard to the efficiency of enzymatic hydrolysis of the cellulose. ...

The use of the hemicellulose fraction of biomass may be important for the feasibility of the production of second generation bioethanol. Wild strains of Saccharomyces cerevisiae are widely used in industry for production of 1st generation ethanol, and the robustness of this yeast is an important advantage in large scale ...

Ethanol was produced using the simultaneous saccharification and fermentation (SSF) method with macroalgae polysaccharide from the seaweed Saccharina japonica (Sea tangle, Dasima) as biomass. The seaweed was dried by hot air, ground with a hammer mill and filtered with a 200-mesh sieve prior to pretreatment. Saccharification was carried out by ...

A cascade type of fermentation, designated the cascade simultaneous saccharification and fermentation (CSSF), was studied to convert corn stover derived pentose and hexose to ethanol with reduced enzyme input. In detail, each step of CSSF utilizes two sequential SSF phases operating on pentose and hexose, i.e., pentose conversion using xylanase, ...

Both stability and catalytic activity of two commercial immobilized lipases were investigated in the presence of different organic solvents in ultrasound-assisted system. In a general way, for Novozym 435, the use of ethanol as solvent led to a loss of activity of 35% after 10 h of contact. The use of ...

Ethanol yields were 2.1 (p = 0.06) to 2.3 (p = 0.01) times higher in simultaneous saccharification and fermentation (SSF) reactions of microcrystalline cellulose when cellulase was physisorbed on silica nanoparticles compared to enzyme in solution. In SSF reactions, cellulose is hydrolyzed to glucose by cellulase while yeast simultaneously ferments glucose to ethanol. The ...

Cellobiohydrolase (CBH) is an important enzyme for the conversion of lignocellulosic biomass to ethanol. This work separated the glycoforms of CBH possessing different numbers of neutral mannoses using capillary zone electrophoresis (CZE) in a 50mM, pH 7.5 phosphate buffer. The method analysed CBH in an intact form using a polyacrylamide ...

Efficient conversion of xylose to ethanol is an essential factor for commercialization of lignocellulosic ethanol. To minimize production of xylitol, a major by-product in xylose metabolism and concomitantly improve ethanol production, Saccharomyces cerevisiae D452-2 was engineered to overexpress NADH-preferable xylose reductase mutant (XR(MUT)) and NADH-dependent xylitol dehydrogenase (XDH) from Pichia ...

Cold enzymatic hydrolysis conditions for bioethanol production were optimized using multi-objective optimization. Response surface methodology was used to optimize the effects of α-amylase, glucoamylase, liquefaction temperature and liquefaction time on S. cerevisiae biomass, ethanol concentration and starch utilization ratio. The optimum hydrolysis conditions were: 224IU/g(starch) α-amylase, 694IU/g(starch) glucoamylase, 77°C and ...

A fermentation process, which was designated the enhanced dry grind enzymatic (EDGE) process, has recently been developed for barley ethanol production. In the EDGE process, in addition to the enzymes normally required for starch hydrolysis, commercial β-glucanases were used to hydrolyze (1,3)(1,4)-β-D: -glucans to smaller molecules, thus reducing the viscosity ...

Agents with phase II enzyme inducing activities play important roles in intervening in the carcinogenic process. In the present study, the quinone reductase (QR) inducing activities of nine known triterpene saponins from the dichloromethane/ethanol extract of the roots of Pulsatilla chinensis were tested. The oleanane saponins exhibited more potent QR ...

The potential of a fungal pretreatment combined with a mild alkali treatment to replace or complement current physico-chemical methods for ethanol production from wheat straw has been investigated. Changes in substrate composition, secretion of ligninolytic enzymes, enzymatic hydrolysis efficiency and ethanol yield after 7, 14 and 21days of solid-state fermentation ...

The potential of the waste from beer fermentation broth (WBFB) for the production of bio-ethanol using a simultaneous saccharification and fermentation process without any extra additions of saccharification enzymes, microbial cells or carbohydrate was tested. The major microbial cells in WBFB were isolated and identified. The variations in compositions of ...

Algae biomass is a potential raw material for the production of biofuels and other chemicals. In this study, biomass of the marine algae, Ulva lactuca, Gelidium amansii,Laminaria japonica, and Sargassum fulvellum, was treated with acid and commercially available hydrolytic enzymes. The hydrolysates contained glucose, mannose, galactose, and mannitol, among other ...

A rapid and highly sensitive miniaturized amperometric biosensor for the detection of α-ketoglutarate (α-KG) based on a carbon fiber electrode (CFE) is presented. The biosensor is constructed by immobilizing the enzyme, glutamate dehydrogenase (GLUD) on the surface of single carbon fiber modified by co-deposition of ruthenium (Ru) and rhodium (Rh) ...

Efficient ethanol producing yeast Saccharomyces cerevisiae cannot produce ethanol from raw starch directly. Thus the conventional ethanol production required expensive and complex process. In this study, we developed a direct and efficient ethanol production process from high-yielding rice harvested in Japan by using amylase expressing yeast without any pretreatment or ...

When scaling up lignocellulose-based ethanol production, the desire to increase the final ethanol titer after fermentation can introduce problems. A high concentration of water-insoluble solids (WIS) is needed in the enzymatic hydrolysis step, resulting in increased viscosity, which can cause mass and heat transfer problems because of poor mixing of ...

Two acidic β-glucosidases (βGI and βGII) from the brown rot fungus Fomitopsis palustris were purified to homogeneity by several chromatographic steps. βGI and βGII had molecular weights of 130 and 213kDa, respectively, and exhibited optimum activity at pH 2.5 and 55°C. The K(m) values of βGI and βGII for p-nitrophenyl-β-d-glucopyranoside ...

Chromogenic microplate assays in 96 wells were used to determine the stability of enzyme activity in frass of Blattella germanica (Blattodea: Blattellidae). Frass samples were exposed to controlled conditions [temperature 15-35 °C and/or 53-100% relative humidity (RH)] and to household conditions (apartment). Exposure times were 0 (control), 90, 183 and ...

The effect of Pb(2+) ions on the Na(+),K(+)-ATPase was investigated in detail by means of steady-state fluorescence spectroscopy. Experiments were performed by using the electrochromic styryl dye RH421. It is shown that Pb(2+) ions can bind reversibly to the protein and do not affect the Na(+) and K(+) binding affinities ...

Although in vitro data from our previous studies show that the antioxidant effect and reactions of both diphenyl diselenide (DPDS) and dicholesteroyl diselenide (DCDS) towards thiol-containing proteins differ considerably, the present study sought to evaluate the interaction of both organodiselenides with thiol-containing proteins in vivo. Mice were injected subcutaneously with ...

Phytanic acid (Phyt) tissue concentrations are increased in Refsum disease and other peroxisomal disorders characterized by neurologic damage and brain abnormalities. The present work investigated the in vitro effects of Phyt, at concentrations found in these peroxisomal disorders, on important parameters of energy metabolism in brain cortex of young rats. ...

The gene encoding a glycoside hydrolase (GH) family 45 endoglucanase (Cel45A) was cloned from P. decumbens 114-2 and expressed in Pichia pastoris. To our knowledge, this is the first report of characterization of a GH family 45 protein from Penicillium species. The purified recombinant enzyme showed a higher activity on ...

Osmolytes KCl, glycerol, mannitol, trehalose, sucrose, betaine, proline and Na-glutamate at different concentrations (5-30%) were investigated as effective solutes for retaining the activity of Halobacterium sp. SP1(1) protease in the absence of NaCl. Maximum activity was observed in the presence of 30% Na-glutamate. Kinetic and thermodynamic parameters for casein hydrolysis ...

There is concern regarding oil sands process water (OSPW) produced by the oil sands industry in Alberta, Canada. Little is known about the potential for OSPW, and naphthenic acids (NAs), which are the primary persistent and toxic constituents of OSPW, to affect endocrine systems. Although ozonation significantly reduces concentrations of ...

The Na+-translocating NADH:ubiquinone oxidoreductase (Na+-NQR) is a component of the respiratory chain of various bacteria. This enzyme is an analogous but not homologous counterpart of mitochondrial Complex I. Na+-NQR drives the same chemistry and also uses released energy to translocate ions across the membrane, but it pumps Na+ instead of ...

The toxic effects of diazinon and its irradiated solutions were investigated using cultivated human blood cells (lymphocytes and erythrocytes) and skin fibroblasts. Ultra Performance Liquid Chromatography (UPLC)-UV/VIS system was used to monitor the disappearance of starting diazinon during 115-min photodegradation and formation of its by-products (diazoxon and 2-isopropyl-6-methyl-4-pyrimidinol (IMP)) as ...

The kinetics of Na+ activation of brush border sucrase (sucrose D-glucosidase E.C. 3.2.1.48) has been studied in mice intestine. At pH 5.0, 50 mM Na+ ions stimulated sucrase activity by 84%. At pH 7.2, enzyme stimulation was reduced to 16%, whereas, atpH 8.5, 10-100 mMNa+ ions produced 18-45% inhibition of ...

ATPase activity of the membrane-bound Na(+)-ATPase of an alkaliphilic bacterium, Exiguobacterium aurantiacum, was measured in various concentrations of NaCl. Hill plot analysis showed a Hill number of 1.7 with 5.2 mM as the K(0.5) value for Na(+). When the site-directed mutagenesis of seven charged amino acid residues in the cytoplasmic ...

Detecting the vitality of mechanical skin wounds (antemortem versus postmortem injury) in human cadavers remains a specifically forensic problem. To determine whether skin mast cells (MCs) are activated during the very early phase of human wound healing we performed a histomorphometric evaluation of the extent of MC enzyme loss as ...

The Mg(2+) dependence of the kinetics of the phosphorylation and conformational changes of Na(+),K(+)-ATPase was investigated via the stopped-flow technique using the fluorescent label RH421. The enzyme was preequilibrated in buffer containing 130 mM NaCl to stabilize the E1(Na(+))(3) state. On mixing with ATP, a fluorescence increase was observed. Two ...

Fetal programming of adult disease is an area of research that has gained considerable attention. Epidemiological studies suggest that adverse intrauterine environment in fetal life is associated with a higher incidence of hypertension and coronary disease. Several mechanisms could contribute to these diseases and be regulated in a tissue-specific manner. ...

BACKGROUND: Subclinical mastititis (SCM) is a condition with raised milk concentration of sodium and milk immune factors. The milk enzymes N-acetyl-beta-D-glucosaminidase (NAGase), lactate dehydrogenase (LDH), acid phosphatase (AcP), and alkaline phosphatase (AP) have attracted attention in dairy research as indicators of SCM, udder health, and milk quality. STUDY DESIGN: To ...

The properties and microbial turnover of exopolymeric substances (EPS) were measured in a hypersaline nonlithifying microbial mat (Eleuthera, Bahamas) to investigate their potential role in calcium carbonate (CaCO(3)) precipitation. Depth profiles of EPS abundance and enzyme activities indicated that c. 80% of the EPS were turned over in the upper ...

We describe an assay for the enzyme Na/K-ATPase in intact guinea pig livers perfused through the portal vein with modified Hank's solution. The model uses the measurement of non-radioactive rubidium ion incorporation by liver cells, both in the absence and in the presence of the specific Na/K-ATPase inhibitor ouabain, followed ...

(Na(+)+K(+))-ATPase is a target receptor of digitalis (cardiac glycoside) drugs. It has been demonstrated that the H1-H2 domain of the alpha-subunit of the (Na(+)+K(+))-ATPase is one of the digitalis drug interaction sites of the enzyme. Despite the extensive studies of the inhibitory effect of digitalis on the (Na(+)+K(+))-ATPase, the functional ...