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L-(+)-Lactate oxidase (EC 1.1.3.2) was immobilized onto the porous side of a cellulose acetate membrane with asymmetric structure which has selective permeability to hydrogen peroxide. The lactate electrode was constructed by combination of a hydrogen peroxide electrode with the immobilized enzyme membrane. Properties ... |
Immobilization experiments have been performed with glucose oxidase as enzyme and controlled-pore glass of different pore sizes as support for chemical coupling. The experimental results have been analyzed for comparison with the theoretical model predictions. Analysis of the initial stage of the process gives the fund... |
Two rate equations have been developed to model the hydrolysis of ground lean meat protein by Alcalase. The first equation was based on classical Michaelis-Menten kinetics and the second on the adsorption of enzyme to the protein prior to reaction. It was assumed that this adsorption could be modelled by a Langmuir-typ... |
Acid phosphatase (E.C. 3.1.3.2) undergoes complex thermal deactivation phenomena, as revealed by the two-slope pattern of the enzyme logarithmic-specific-activity versus time curves. The native enzyme first decays toward an equilibrium distribution of less, but still active, intermediate structures and these, in turn, ... |
For the recovery of intracellular material from bacteria it is often necessary to disrupt the cells. Much work has been done on the kinetics of protein release in beadmills,(1) homogenizers,(2) and by ultrasonication.(3) In this paper we report how the growth phase of Bacillus amyloliquefaciens grown in batch culture a... |
Pretreatment of lignocellulosic materials with alkaline hydrogen peroxide greatly increases their susceptibility to enzymatic cellulose hydrolysis. During the course of the pretreatment reaction (18 h), the pH rises slowly, increasing from pH 11.5 to a final pH > 12. As a result, most of the hemicellulose in the lignoc... |
This study is concerned with characterizing cell-bound inducible beta-xylosidase produced by a strain of the thermophilic bacterial genus Thermomonospora. A crude preparation of this enzyme recovered from sonicated cells of this organism displayed high activity against paranitrophenyl-beta-xylopyranoside over a pH rang... |
Kluyveromyces fragilis immobilized in calcium alginate gel was compared to Saccharomyces cerevisiae coimmobilized with beta-galactosidase, for continuous ethanol production from whey permeate in packed-bed-type columns. Four different whey concentrations were studied, equivalent to 4.5, 10, 15, and 20% lactose, respect... |
Aspergillus japonicus was grown in the presence of various aromatic compounds at 0.1 and 1 mg/mL, and extracellular xylanase and arabanase activities were measured. Some of the aromatic compounds tested, especially at the higher concentration, suppressed the appearance of hemicellulase activities, expressed as xylanase... |
This article deals with the mathematical modeling of the process of enzyme immobilization in porous membranes. During the initial period, an analytical solution is available to extract the rate constant for immobilization. Beyond this period, the model equations are solved numerically to yield the transient response of... |
Aspergillus fumigatus was cultured in disc-turbine-agitated vessels and in an air-lift fermentor. In the agitated vessels the yield of cellulase was reduced when the agitation rate was increased, although extracellular protein levels rose. The enzyme complex itself was shown to be exceptionally stable under conditions ... |
The leaching of a zinc sulfide concentrate by Thiobacillus ferrooxidans was investigated in continuous stirred tank reactors. A mathematical model for the growth of T. ferrooxidans on this solid substrate is presented and tested. Experimental leaching studies were done using two reactors in series with and without recy... |
The hollow fiber enzyme reactor with pulsation developed by Kim and Chang (1983) was operated in a differential mode by recycling a substrate solution, in order to assess the efficiency of ultrafiltration swing. The rates of lactose conversion by beta-galactosidase contained in the shell side of the reactor were measur... |
It has been shown that the Upflow Anaerobic Sludge Bed (UASB) system data reported earlier(1) cannot be explained by simple Monod-type substrate consumption patterns. An autoinhibition model was also ruled out because the substrate concentration range over which hysteresis was observed was much larger than such a model... |
Nutrient deprivation was used to synchronize an immobilized live cell culture of Acetobacter suboxydans. The substrate supply was increased by a step change in the dilution rate to the reactor. Oscillations in cell, substrate, and product concentrations were observed. A population balance model was developed to explain... |
The optimal periodic operation of the biological reactor was studied from the standpoint of the two-objective programming problem. The noninferior set with respect to the cell productivity and the conversion of the substrate into the biomass was determined by use of the optimization technique due to Miele. It was shown... |
The production of sugars by the enzymatic hydrolysis of cellulose is a two-step process that includes conversion of the intermediate cellobiose to glucose by beta-glucosidase. The hydrolysis was followed by analyzing the two sugar products (cellobiose and glucose). The enzyme showed maximum activity at pH 4.8. Thermal ... |
A significant portion of the total biodegradative activity toward synthetic compounds may involve cometabolism; thus, the latter represents an important type of microbial process. A mixed microbial population acclimated to highstrength industrial wastewater degraded about 90% of the organic carbon present in the wastew... |
A new method for solid-state ethanol fermentation (the SSEF system) was experimented on for the ethanol production from solid starchy materials, where a packedbed-type fermentor was used. Both cultivation of Aspergillus saitoi and enrichment of a saccharifying enzyme were effective for hydrolysis of the starch. Ethanol... |
The fermentation and recovery of the EcoRl restriction endonuclease with a genetically modified Escherichia coli strain is investigated. Vast amounts of product could be obtained after cultivation in a 20-L computer-coupled pilot fermentor and purification of the recovered wet cells. It was found that in the end the pr... |
The kinetics of the enzymatic hydrolysis of sodium hydroxide-pretreated sallow were studied in an ultrafiltration membrane reactor in the presence of different concentrations of glucose. In the UF membrane reactor low-molecular-weight products were continuously removed at a low dilution rate and replaced by a buffer so... |
The yeast cells of Pichia farinosa Y-118 were immobilized in polyacrylamide gel and used for 17 beta-oxidoreduction of secondione to secol. The loss of hydroxysteroid oxidoreductase activity of cells was found to be insignificant during immobilization. The preparation exhibited greater temperature stability as compared... |
Significant increase in extracellular cellulase and hemicellulase activities was observed in the biosynthesis of cellulase enzyme in mixed culture fermentation of Trichoderma reesei D 1-6 and Aspergillus wentii Pt 2804 when the A. wentii inoculation was phased by 15 h. The optimal conditions of fermentation by the mixe... |
Cellulase production from lignocellulosic materials was studied in solid-state cultivation by both static and mixed techniques under nonaseptic conditions. The effects of fermentation conditions, such as moisture content, pH, temperature, and aeration, on cellulase production by Trichoderma harzianum using a mixture of... |
The production of extracellular cellulases by Chaetomium cellulolyticum could be induced by slow feeding of cellobiose to the cultures. Both the rate of production and the amount of activity were comparable to that obtained in batch cultivation on cellulose. The specific filter paper activity of 2.06 U per mg protein w... |
A comparative study on the saccharification of pretreated rice straw was brought about by using cellulase enzyme produced by Aspergillus terreus ATCC 52430 and its mutant strain UNGI-40. The effect of enzyme and substrate concentrations on the saccharification rate at 24 and 48 were studied. A syrup with 7% sugar conce... |
The principal objective of this study was the development and evaluation of a comprehensive kinetic model capable of predicting digester performance when fed biological sludge, preliminary conversion mechanisms such as cell death, lysis, and hydrolysis responsible for rendering viable biological sludge organisms to ava... |
An immobilized enzyme reactor has been developed for the degradation of bilirubin as a potential treatment for neonatal jaundice. It utilizes the enzyme bilirubin oxidase from Myrothecium verrucaria, which in the presence of molecular oxygen converts bilirubin to biliverdin and other products that are much less toxic t... |
The injection of a volatile tracer in the gas flow allowed to describe the residence time distribution (RTD) in a solid substrate reactor. The chromatographic analysis of Dirac impulses of acetone led to identify the fermentor as a first-order rate system. The evolution of the time constant (lambda) of the system versu... |
A comprehensive kinetic study of the acid hydrolysis of concentrated brewing bagasse slurries was performed. The use of the simple series reaction model was found to be suitable when a "heterogeneous correction" (pseudosubstrate-inhibition) is taken into account in slurries with low liquid-to-biomass ratios. Rate const... |
This research is aimed at understanding the reactor-settler interaction. The reactor operating conditions affect the sludge-settling properties due to (a) production of exocellular polymer that serves as a flocculant in the settler and (b) population shift from flocculating bacteria to filamentous microorganisms that d... |
A mathematical model has been developed for the internal pH control in immobilized enzyme particles. This model describes the kinetics of a coupled system of two enzymes, immobilized in particles of either planar, cylindrical, or spherical shape. The enzyme kinetics are assumed to be of a mixed type, including Michaeli... |
Several recent studies have documented that supplementation with pomegranate fruit extract inhibits inflammatory symptoms in vivo. However, the molecular basis of the observed effects has not been fully revealed. Although previous studies have documented the inhibition of nitric oxide and cyclooxygenase (COX) activity ... |
A simple procedure for the entrapment of enzymes in nylon-reinforced cellulose triacetate fibers and the fabrication of reusable enzyme brushes using such fiber bristles for the analytical determination of unknown samples have been described. As an example, enzyme brushes of lactate dehydrogenase were fabricated and we... |
To calculate the transient accumulation of soluble organic matter in activated sludge, an equation based on COD and respirometry is described. In this approach the difference between the actual utilized organic matter and the metabolized matter is expressed as substrate transient accumulation. The amount of substrate g... |
Tests on acid phosphatase (E.G. 3.1.3.2) deactivation by urea have been performed at two pH values. Two conditions have been used: native enzyme operating batch-wise in dilute solution and stabilized enzyme in continuous flow ultrafiltration membrane reactor. Stabilization is achieved by confining the enzyme within a c... |
Culture filtrates from Trichoderma harzianum E58, T. reesei CL 847 and Penicillium sp. C 462 were assayed for beta-glucosidase activity using a range of substrates and sugar analysis methods. Although sugar analyses by the dinitrosalicylic acid (DNS) and Nelson-Somogyi methods gave a similar profile, when increasing co... |
A structured mathematical model for cellular metabolism in Escherichia coli has been extended to encompass the mechanistic structure surrounding the kinetics and control of transcription and translation. The dependence of transcription on RNA polymerase and the mechanism of translation initiation have been explicitly i... |
Yeast nucleoproteins were chemically phosphorylated with phosphorus oxychloride (POCL(3)). Studies using (31)P nuclear magnetic resonance (NMR) spectroscopy, stability to pH and lysine estimation all indicated that the epsilon-amino group of lysine was the principal functional group phosphorylated. Phosphorylation of c... |
A mathematical model describing the change in effectiveness factor or effective diffusivity for the intermediate substrate in sequential substrate removal reactions in fixed biofilms is developed. Typical results from the numerical solution of the resulting equation are presented. The production of intermediate substra... |
Chondroitinase ABC catalyzing the depolymerization of chondroitin sulfate was induced by incubating the Proteus vulgaris cells in a medium containing chondroitin C sulfate as an inducer. Incubation of P. vulgaris cells for 12 h in the presence of 0.3% inducer was optimal to obtain the cells with highly active chondroit... |
Glucoamylase, invertase, and cellulase were entrapped within poly(vinyl alcohol) (PVA) membrane cross-linked by means of irradiation of ultraviolet light. The conditions for immobilization of glucoamylase were examined with respect to enzyme concentration in PVA, sensitizer (sodium benzoate) concentration in PVA, irrad... |
The utilization of mixtures of methanol (C(1)) and glucose (C(6)) of different composition by the methylotrophic yeast Hansenula polymorpha was studied in carbon-limited chemostat culture. For all mixtures tested a similar utilization pattern was observed: At low dilution rates both carbon sources were utilized simulta... |
A mixed culture of Saccharomyces cerevisiae and Escherichia coli was established in a stable coexistence steady state in a chemostat under constant operating conditions. The species competed for glucose, the growth-limiting resource, and produced acetate and ethanol. The acetic acid was shown to be very inhibitory to E... |
The irradiation with visible light of a photosensitizer dye like methylene blue was used to regenerate by electron transfer the oxidized form of a pyridine nucleotide coenzyme (NAD(+)). The process has been studied on a common enzymatic reaction: ethanol oxidation by alcohol-NAD(+) oxidoreductase immobilized on polyacr... |
A new immobilization technique suitable for coupled enzymes requiring cofactors was established. This is a droplet gel-entrapping method in which many small droplets including the enzymes are fixed in the gel. The first emulsion was prepared by mixing of a solution containing thermostable malate dehydrogenase (MDH) and... |
Hydroxyurea, an inhibitor of DNA synthesis in Saccharomyces cerevisiae, has been applied in order to restrict growth of immobilized cells. For comparison, the influence of hydroxyurea on suspended S. cerevisiae has also been investigated. Recovery from DNA synthesis inhibition, indicated by measurements of cell growth ... |
Thiobacillus ferrooxidans, the bacterium most widely used; in bioleaching or microbial desulfurization studies, was grown in an electrolytic bioreactor containing a synthetic, ferrous sulfate medium. Passage of current through the medium reduced the bacterially generated ferric iron to the ferrous iron substrate. When ... |
Cellulase produced by fungus Trichoderma viride was immobilized on agarose beads (Sepharose 4B) activated by cyanogen bromide and also on activated agarose beads that contained spacer arm (activated CH-Sepharose 4B and Affi-Gel 15). The CMCase activity retained by immobilized cellulase on activated Sepharose containing... |
Using a continuum approach and observing conservation principles, an analytical mathematical model of microbial interaction in biofilms was developed. The model predicts changes in biofilm thickness and describes the dynamics and spatial distribution of microbial species and substrates in the film. It allows for biomas... |
Nocardia corallina B276 cells were immobilized by emulsification with liquid paraffin and an antifoam agent at room temperature. The immobilized cells were studied for their ability to carry out the formation of propylene oxide from propylene and oxygen. The evaluations were done with the cells in a bubble-type reactor... |
The kinetics of precipitation of soya protein has been examined in a tubular flow reactor with the precipitants, ammonium sulfate, ethanol, divalent calcium, and sulfuric acid. The precipitate growth profiles obtained in all cases showed the rapid formation of a precipitate phase and the attainment of a final size with... |
The ligninolytic activities of four cellulolytic organisms were compared using straw. Only Aspergillus japonicus and Polyporous versicolor appreciably degraded lignin with A. japonicus yielding the most protein. In solid culture, most protein was produced by P. versicolor, closely followed by A. japonicus. Pretreatment... |
Mold growth and differentiation are closely related to the formation of secondary products. In solid-substrate fermentations this interrelationship is often more completely realized than in submerged cultures. Solid substrate reactions are used commercially in a limited manner in the western world, but are relatively c... |
Horseradish peroxidase has been found to vigorously act as a catalyst in a number of water-immiscible organic solvents. The rates of peroxidase-catalyzed oxidation of p-anisidine with H(2)O(2) in toluene, benzene, ethyl and butyl acetates, and ether are in the range of 10-25% of that in water (pH 7.0) at the same react... |
Hollow fiber ultrafiltration and microfiltration membranes are examined for the processing of isoelectric soya protein precipitate suspensions. A model based on the various resistances to permeate flux is used to describe membrane performance. The main resistance to permeate flux is due to the interaction between the a... |
The activity of an immobilized enzyme in a packed bed is monitored for the change in a substrate conversion with time. But pressure drop in the packed bed with immobilized glucoamylase can serve as an indirect indicator for the changes in the conversion and activity of the immobilized enzyme. The method is simple and t... |
Growth of a hybridoma culture, along with production of monoclonal antibody, was demonstrated over extended periods in polysulfone hollow fiber membrane modules. The molecular weight cutoffs of the membranes were 70,000, 50,000, and 100,000 daltons. The hybridoma cell line, designated 65/26, produced IgG (2b/kappa) dir... |
A nitrate control system has been devised for the maintenance of stable nitrate concentrations throughout fed-batch fermentations of Corynebacterium glutamicum. The feedback control system was based on the use of a nitrate-ion-selective electrode to directly monitor the nitrate levels in the fermentor and an automatic ... |
Experiments were carried out to identify an efficient procedure for decreasing the amount of excess sludge in deep aeration columns. Incubation characteristics, especially cellular yield, are closely related to excess sludge, maximum specific growth rate, and chemical oxygen demand. They were measured here for the bact... |
Both the forward and backward reactions of xylose isomerase (Sweetzyme Q) with xylose and glucose as substrates have been studied in terms of kinetics and thermodynamics. The relationship between the two reactions can thus be determined. Much attention has been given to the reaction with xylose as substrate. The optima... |
Alcoholic fermentations of starch hydrolysate by two different yeast strains, Saccharomyces cerevisiae(var. Vinal) and Saccharomyces oviformis(IMAP 383), have been studied in batch runs. In order to evaluate the different inhibition phenomena due to both substrate and product, a new kinetic equation is suggested. |
A comparison of the relative performance of production techniques using coenzyme or cofactor electrochemical regeneration demonstrates the superiority of those processes in which the enzymatic reaction and the regeneration are conducted in the same reactor as opposed to those in which the reaction and regeneration are ... |
Material balances for pentosan, lignin, and hexosan, during steam-explosion pretreatment of aspenwood, showed almost quantitative recovery of cellulose in the water-insoluble fraction. Dilute acid impregnation resulted in more selective hydrolysis of pentosan relative to undesirable pyrolysis, and gave a more accessibl... |
A kinetic model that represents the reaction of hydrolysis of water-soluble cellulose derivatives by a mixed endo- and exoenzyme system is proposed with the following assumptions: at an early stage of the reaction, endoenzymes split the substrate molecule in order to supply the newly formed nonreducing ends to exoenzym... |
A novel mechanistic model for the growth of baker's yeast on glucoseis presented. It is based on the fact that glucose degradation proceeds via two pathways under conditions of aerobic ethanol formation. Part is metabolized oxidatively and part reductively, with ethanol being the end product of reductive energy metabol... |
Warfarin treatment has a narrow therapeutic range, requiring meticulous monitoring and dosage titration. Individual dosage requirement has recently partly been explained by genetic variation of the warfarin metabolizing enzyme CYP2C9 and the Vitamin K-activating enzyme VKORC1. In the WARIS-II study, comparing three dif... |
Splenogastric hygropyrexia syndrome, a common syndome in clinical practice, responds well to the therapy of traditional Chinese medicine (TCM). In view of the complexity of TCM syndrome formation, proceeding from different aspects such as Helicobacter pylori (Hp) infection, expression of inflammatory factors, mucosal p... |
The lymphatic vasculature is essential to fluid, protein and cellular transport, and to immune responsiveness. The last decade has witnessed a virtual renaissance of investigation into the function of the lymphatic microvasculature, prompting re-consideration of its role in the genesis and progression of cardiovascular... |
Differential transcription in Ascaris suum was investigated using a genomic-bioinformatic approach. A cDNA archive enriched for molecules in the infective third-stage larva (L3) of A. suum was constructed by suppressive-subtractive hybridization (SSH), and a subset of cDNAs from 3075 clones subjected to microarray anal... |
This article describes the headlines of the Educational Program on Personality Disorders produced by the WPA Section on Personality Disorders and the International Society on the Study of Personality Disorders. Lifelong personality traits serve as a substrate and a context for understanding more florid and distinct for... |
The effects of acute cooling/rewarming on cardiac K(+) currents and membrane potential were investigated. Membrane potential and current were assessed with whole-cell patch-clamp technique in current- and voltage-clamp modes. When the temperature of bath solution was decreased from 25 °C; to 4 °C, the transient outward... |
The present study was designed to observe the expression and distribution of connexin 43 (Cx43) in myocardium of rats after repeated positive acceleration (+Gz) exposures. Thirty six male Sprague-Dawley rats were randomly divided into 3 groups (n=12): control group, +6Gz group and +10Gz group. The rats in +6Gz group we... |
Arginine vasopressin (AVP), a neurohormone and hemodynamic factor implicated in the pathophysiology of hypertension and congestive heart failure, can also act as a growth-stimulating factor. Our previous work demonstrated that AVP is a mitogen for neonatal rat cardiac fibroblasts (CFs). In the present study, we extende... |
The present study aimed to investigate the effects of interleukin-1β (IL-1β) at different doses on collagen synthesis and decomposition in cultured cardiac fibroblasts from neonatal Sprague-Dawley rat. Cardiac fibroblasts were treated with IL-1β (0.01, 0.1, 1, 10, 100 ng/mL) for 24 h. Cell DNA synthesis was measured by... |
A gene that could be potentially involved in spermatogenesis was identified and characterized by using suppression subtractive hybridization (SSH) and rapid amplification of cDNA ends (RACE) with total RNA from type A spermatogonia and pachytene spermatocytes of rat. This gene consists of 3 433 base pairs (bp) with a c... |
The present study aimed to investigate the effect of proto-oncogene c-src on the viability of rat spermatogonial stem cells from 9 day-old rat in vitro. MTT method was used to observe the viability of the spermatogonial stem cells treated with antisense c-src oligodeoxynucleotides (ODNs) in vitro; RT-PCR was utilized t... |
High-density lipoprotein (HDL), an abundant plasma lipoprotein, has been thought to be anti-inflammatory in both health and infectious diseases. It binds lipopolysaccharide (LPS) and neutralizes its bioactivity. The present study aimed to investigate the potential role of HDL, which was separated from human plasma, in ... |
The process of injury and repair in airway epithelium involves cell spreading and migration followed by cell proliferation. IQ domain GTPase-activating protein 1 (IQGAP1) acts in a series of cell processes, but has not been clarified in lung epithelial cells. In this study, a widely used model of injury and repair in v... |
In recent years, there has emerged academic tendency towards the neurogenic mechanism of ulcerative colitis (UC). As one of the supports to the hypothesis of UC being a neurogenic inflammation, we have built a colitis model by intrathecal (ith) injection of a haptten 2,4-dinitrochlorobenzene (DNCB) to DNCB-sensitized r... |
Strong proliferative capacity and the ability to differentiate into the derivative cell types of three embryonic germ layers are the two important characteristics of embryonic stem cells. To study whether the mesenchymal stem cells from human fetal bone marrow (hfBM-MSCs) possess these embryonic stem cell-like biologic... |
The use of stem cells will lead to novel treatments for a wide range of diseases due to their properties of self-renewing, pluripotent, and undifferentiated state, and the stem cells are usually genetically modified for cell and gene therapy. If the baculovirus, as a new gene vector, can be effectively transduced into ... |
Extracellular signal-regulated kinase 1/2 (ERK1/2) pathway has been shown to be important for regulating cell proliferation and survival. The role of ERK1/2 signaling in the survival and growth of neural stem cells (NSCs) has not been addressed adequately. In this work, we aimed to provide evidence that proliferation o... |
A protein based 3D porous scaffold is fabricated by blending gelatin and albumin. The biomimetic biodegradable gelatin, promoted good cell adhesion and its hydrophilic nature enabled absorption of culture media. Albumin is proposed to serve as a nontoxic foaming agent and also helped to attain a hydrophobic-hydrophilic... |
The productivity of a cell mass of Saccharomyces cerevisiae and enzymes of Eupenicillium javanicum increased by cultivation in anair-solid fluidized bed fermentor with agitators. The usefulness of the apparatus for the fluidized bed culture was verified. The productivity of amyiase and protease of the fungus by fluidiz... |
Thermostable lipase from Thermomyces lanuginosus was immobilized in untreated microporous membranes. Melted tallow pumped through the membrane did not wash the enzyme out. From 0.4 to 0.9% of the soluble activity remained after immobilization with half-lives of 1-2 months or more at 50 degrees C. Membranes can be acid/... |
The Pronounced differences in performance of a strain of Clostridium acetobutylicum ATCC 824 were analyzed by the method of systems analysis. The mechanism for cellular transport of substrate (glucose), solvents, and acids was studied and mathematically formulated. The systems analysis approach in the treatment of data... |
A substrate control system based upon dialysis culture techniques has been developed. In fermentations of Escherichia coli where phosphate or sulfate concentrations were controlled, the relation between the apparent specific growth rate, mu, and the phosphate concentration followed Monod kinetics, while the relation be... |
Lytic enzyme systems with the ability to break whole cells of yeast are a mixture of several enzymes and virtually all contain beta(1-3)glucanases and some protease. It appears that the presence of these two enzyme activities is necessary to break the two layers of the rigid cell wall. The enzyme system of Cytophaga NC... |
The maximum conversion of hydrocortisone suspensions at initial substrate concentrations greater than 4 g/L by immobilized Arthrobacter simplex in a batch reactor was 80-85%. By feeding hydrocortisone suspensions continuously to either a fed-batch-operated stirred tank reactor or to a continuous-flow airlift loop react... |
Based upon the general characteristics of the optimal feed rate profiles presented in an earlier article, efficient computational algorithms have been developed for fed-batch fermentation processes described by four or less mass balance equations. These algorithms make computations of optimal substrate feed rate profil... |
The optimal substrate feeding policy for the fed batch fermentation which is governed by product and substrate inhibited kinetics is presented. The conjunction point between nonsingular and singular arcs and the feeding policy along the singular arc are derived analytically in terms of the concentrations of substrate a... |
Coimmobilization of biocatalyst and substrate was studied as a method to increase the conversion rate in systems with substrates of extremely low solubility in water. The system studied was the conversion of hydrocortisone to prednisolone by Arthrobacter simplex. As a matrix for coimmobilization, alginate turned out to... |
A series of novel water-soluble hemicellulosic derivatives, containing carbamoylethyl and carboxyethyl groups, were heterogeneously synthesized from wheat-straw hemicelluloses with acrylamide (AA) under alkaline conditions. The factors such as reaction temperature, reaction time, molar ratio of catalysis to xylose unit... |
The catechol-O-methyltransferase (COMT) enzyme catabolizes dopamine. The val(158)met single nucleotide polymorphism (rs4680) in the COMT gene has received considerable attention as a candidate gene for schizophrenia as well as for frontally mediated cognitive functions. Antisaccade performance is a good measure of fron... |
The "experiences" reported by individuals affected by schizophrenia are fundamental components of the descriptive approach adopted by current diagnostic systems for mental disorders and by clinical diagnostic interviews and rating scales for the assessment of the symptoms of schizophrenia. However, the technical litera... |
A case of adrenal rest tumor in the liver of a 67-year-old female was reported. The tumor appeared on diagnostic imaging as a hypervascular and fat-containing mass at the periphery of right hepatic lobe and required differential diagnosis from hepatocellular carcinoma (HCC). Pathological diagnosis of the intraoperative... |
Plum pox virus (PPV) infects stone-fruit trees with important economical impact mainly in Europe and Mediterranean region. The data about PPV intra-species variability accumulated markedly in the last two decades. Six PPV strains have been recognized using different approaches including serology, protein analysis, spec... |
Murine gammaherpesvirus 68 (MHV-68) contains gene-encoding M3 protein expressed during the acute and persistent phase of infection. This protein features a chemokine-binding activities (Parry et al., 2000; van Berkel et al., 2000). In this study, we demonstrated that the Murine gammaherpesvirus 72 (MHV-72) also contain... |
Mutations of the tryptophan residues in the tryptophan-track of the N-terminal domain (W33F/Y and W69F/Y) and in the catalytic domain (W245F/Y) of Serratia sp. TU09 Chitinase 60 (CHI60) were constructed, as single and double point substitutions to either phenylalanine or tyrosine. The enzyme-substrate interaction and m... |
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