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Enzymatic Hydrolysis (enzymatic + hydrolysis)
Selected AbstractsENZYMATIC HYDROLYSIS OF SOYBEAN FOR SOLVENT AND MECHANICAL OIL EXTRACTIONJOURNAL OF FOOD PROCESS ENGINEERING, Issue 4 2000PRAVEEN C. BARGALE ABSTRACT Due to inefficient extractability of its low oil content, soybeans are often bypassed in village-scale processing. Soygrits, flakes, and expanded collets were hydrolyzed by proteases, cellulases, and pectinases before oil extraction by solvent and static mechanical pressure. Driselase with multi-enzyme activity and two proteases improved solvent extraction rates but only Driselase enhanced mechanical pressing. Up to 58% of seed oil was pressed from enzyme-hydrolyzed flakes but 88% was pressed from Driselase-treated collets. Either pretreatment is a feasible adjunct to mechanical pressing in small batch operations. [source] A Versatile Synthesis of 5,-Functionalized Nucleosides Through Regioselective Enzymatic Hydrolysis of Their Peracetylated PrecursorsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 12 2009Teodora Bavaro Abstract We describe a chemo-enzymatic synthesis of modified nucleosides through lipase-catalyzed hydrolysis of their peracetylated precursors. It was found from screening of a large number of substrates that these enzymes' regioselectivities were affected by the sugar and the nucleobase structures. By selecting the best enzyme for each substrate in terms of activity and regioselectivity, we prepared a small library of differently monodeprotected purine and pyrimidine nucleosides useful as intermediates for the synthesis of high-value nucleosides and mononucleotides. By this approach, the chemo-enzymatic preparation of doxifluridine (14) anduridine 5,-monophosphate (5,-UMP, 15) from peracetylated uridine 1 was carried out. Elimination of many of the processing stages associated with existing methods was achieved, and higher yields and products of increased purity were generated. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Optimization of the Enzymatic Hydrolysis of Mussel MeatJOURNAL OF FOOD SCIENCE, Issue 1 2010Vanessa M. Silva ABSTRACT:, Mussel meat was subjected to enzymatic hydrolysis using Protamex. The relationship of temperature (46 to 64 °C), enzyme : substrate ratio (0.48% to 5.52%), and pH (6.7 to 8.3) to the degree of hydrolysis were determined. The surface response methodology showed that the optimum conditions for enzymatic hydrolysis of mussel meat were pH 6.85, temperature 51°C, and enzyme : substrate ratio of 4.5%. Under these conditions a degree of hydrolysis of 26.5% and protein recovery of 65% were obtained. The produced hydrolysate, under optimum condition, was characterized in terms of chemical composition, electrophoretic profile, and amino acid composition. Practical Application: The practical application of mussel meat hydrolysate is its use as flavoring in products such as soups, sauces, and special beverages. In addition, the product is partially digested and has great nutritional value due to its good amino acid profile and thus can be used as a food supplement in special diets. [source] Recovery of Components from Shrimp (Xiphopenaeus kroyeri) Processing Waste by Enzymatic HydrolysisJOURNAL OF FOOD SCIENCE, Issue 5 2006Helenice Duarte De Holanda ABSTRACT:, Industrial shrimp waste is a good source of protein, chitin, and carotenoids. In general, this waste is discarded with no attempt to use it, thus contributing to environmental pollution. This study was aimed at recovering the 3 main components of industrial shrimp waste, protein, chitin, and astaxanthin, using enzymatic treatment with Alcalase and pancreatin. An increase in the degree of hydrolysis (DH) from 6% to 12% resulted in 26% to 28% protein recovery. Alcalase was more efficient than pancreatin, increasing the recovery of protein from 57.5% to 64.6% and of astaxanthin from 4.7 to 5.7 mg astaxanthin/100 g of dry waste, at a DH of 12%. The enzymatic hydrolysis of the industrial waste from Xiphopenaeus kroyeri shrimp using Alcalase allowed for 65% protein recovery in the form of hydrolysates, in addition to providing suitable conditions for the recovery of astaxanthin and chitin. [source] Rheological Characterization of a Gel Formed During Extensive Enzymatic HydrolysisJOURNAL OF FOOD SCIENCE, Issue 5 2001D. Doucet ABSTRACT Extensive hydrolysis of whey protein isolate (WPI) by Alcalase 2.4L® caused a dramatic increase in turbidity and viscosity. A gel was formed after the degree of hydrolysis was , 18%, coinciding with < 16%,-lactoglobulin and < 4%,-lactalbumin remaining unhydrolyzed. Heat-induced and enzyme-induced WPI gels were compared. Frequency and strain dependence indicated that both gels could be considered as strong, physical gels. [source] Enzymatic Hydrolysis of , - and , -Oligo(L -aspartic acid)s by Poly(aspartic acid) Hydrolases-1 and 2 from Sphingomonas sp.MACROMOLECULAR BIOSCIENCE, Issue 3 2004Abstract Summary: The enzymatic hydrolysis of , - and , -oligo(L -aspartic acid)s by PAA hydrolase-1 and PAA hydrolase-2 (purified from Sphingomonas sp. KT-1) was performed to elucidate the mechanism of the microbial degradation by Sphingomonas sp. KT-1 of the thermally synthesized ,,, -poly(D,L -aspartic acid) (tPAA). GPC analysis of the hydrolyzed products of , - and , -tetra(L -aspartic acid)s by PAA hydrolase-1 has showed that PAA hydrolase-1 is capable of hydrolyzing only the specific amide bonds between , -aspartic acid units. The RP-HPLC analysis of the enzymatic hydrolysis of , -oligo(L -aspartic acid)s (4 and 5 mers) by PAA hydrolase-1 has suggested that the enzymatic hydrolysis of , -oligo(L -aspartic acid)s occurs via an endo-mode cleavage. In contrast, PAA hydrolase-2 hydrolyzed both , - and , -oligo(L -aspartic acid)s via an exo-mode cleavage to yield L -aspartic acid as a final product. A kinetic study on the enzymatic hydrolysis of , -oligo(L -aspartic acid)s (3 to 7 mers) by PAA hydrolase-2 has indicated that Km values are almost independent of the number of monomer units in oligomers of 4 to 7 mers, while that Vmax values are markedly dependent on the chain length and show a maximum value at 5 mer. A proposed mechanism of the enzymatic hydrolysis of tPAA by PAA hydrolase-1 and PAA hydrolase-2 in the cell of Sphingomonas sp. KT-1. [source] Study on Enzymatic Hydrolysis of Polylactic Acid by Endogenous Depolymerizaion ModelMACROMOLECULAR THEORY AND SIMULATIONS, Issue 6 2007Masaji Watanabe Abstract Enzymatic degradation of polylactic acid is studied experimentally and analytically. Gel permeation chromatography profiles obtained before and after the enzymatic degradation of polylactic acid (PLA) were introduced into the analysis based on a mathematical model. Previously developed techniques were successfully adapted to the analysis of an initial value problem consisting of an endogenous depolymerization model and an initial condition, and an inverse problem to determine the degradation rate for which the solution of the initial value problem also satisfies a final condition. Those problems were solved numerically and numerical results are introduced. Degradabilities of PLA and polyvinyl alcohol are compared. [source] Improving the Industrial Production of 6-APA: Enzymatic Hydrolysis of Penicillin G in the Presence of Organic SolventsBIOTECHNOLOGY PROGRESS, Issue 6 2003Olga Abian The hydrolysis of penicillin G in the presence of an organic solvent, used with the purpose of extracting it from the culture medium, may greatly simplify the industrial preparation of 6-APA. However, under these conditions, PGA immobilized onto Eupergit displays very low stability (half-life of 5 h in butanone-saturated water) and a significant degree of inhibition by the organic solvent (30%). The negative effect of the organic solvent strongly depended on the type of solvent utilized: water saturated with butanone (around 28% v/v) had a much more pronounced negative effect than that of methylisobutyl ketone (MIBK) (solubility in water was only 2%). These problems were sorted out by using a new penicillin G acylase derivative designed to work in the presence of organic solvents (with each enzyme molecule surrounded by an hydrophilic artificial environment) and a suitable organic solvent (MIBK). Using such solvent, this derivative kept its activity unaltered for 1 week at 32 °C. Moreover, the enzyme activity was hardly inhibited by the presence of the organic solvent. In this way, the new enzyme derivative thus prepared enables simplification of the industrial hydrolysis of penicillin G. [source] Enzymatic Hydrolysis of Waste Office Paper Using Viscosity as Operating ParameterBIOTECHNOLOGY PROGRESS, Issue 2 2001Enoch Y. Park Enzymatic hydrolysis of waste office (WO) paper with feeding WO paper in a reactor was investigated using apparent viscosity as operating parameter. Since the apparent viscosity was correlated with the concentration of pulping WO paper, the amount of hydrolyzed WO paper was assumed by measuring the decrease in the apparent viscosity. Then the amount of hydrolysis WO paper and the amount of enzyme corresponding to the desired ratio were fed into the reactor. When the WO paper and 1% (to the amount of WO paper) enzyme were fed to the hydrolytic reaction, 87 g/L of reducing sugar (RS) with a hydrolytic yield of 42.2% was obtained for a 24-h hydrolysis. However, when nonpulping WO paper and 5% (to the amount of WO paper) enzyme were fed to the hydrolytic reaction, 120 g/L of RS with a hydrolytic yield of 40% was obtained for a 24-h hydrolysis. Therefore, the RS concentration from this hydrolysis process feeding WO paper using apparent viscosity as operating parameter may be of sufficient concentration to serve as a carbon source in microorganism culture or chemical feedstock. [source] Enzymatic hydrolysis of sugarcane bagasse for bioethanol production: determining optimal enzyme loading using neural networksJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 7 2010Elmer Ccopa Rivera Abstract BACKGROUND: The efficient production of a fermentable hydrolyzate is an immensely important requirement in the utilization of lignocellulosic biomass as a feedstock in bioethanol production processes. The identification of the optimal enzyme loading is of particular importance to maximize the amount of glucose produced from lignocellulosic materials while maintaining low costs. This requirement can only be achieved by incorporating reliable methodologies to properly address the optimization problem. RESULTS: In this work, a data-driven technique based on artificial neural networks and design of experiments have been integrated in order to identify the optimal enzyme combination. The enzymatic hydrolysis of sugarcane bagasse was used as a case study. This technique was used to build up a model of the combined effects of cellulase (FPU/L) and ,-glucosidase (CBU/L) loads on glucose yield (%) after enzymatic hydrolysis. The optimal glucose yield, above 99%, was achieved with cellulase and ,-glucosidase concentrations in the ranges of 460.0 to 580.0 FPU L,1 (15.3,19.3 FPU g,1 bagasse) and 750.0 to 1140.0 CBU L,1 (2,38 CBU g,1 bagasse), respectively. CONCLUSIONS: The dynamic model developed can be used not only to the prediction of glucose concentration profiles for different enzymatic loadings, but also to obtain the optimum enzymes loading that leads to high glucose yield. It can promote both a successful hydrolysis process control and a more effective employment of enzymes. Copyright © 2010 Society of Chemical Industry [source] Purification and initial characterization of a novel protein with factor Xa activity from Lonomia obliqua caterpillar spiculesJOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 3 2005S. Lilla Abstract A novel protein with factor Xa-like activity was isolated from Lonomia obliqua caterpillar spicules by gel filtration chromatography and reversed-phase high-performance liquid chromatography. The protein had a mass of 20745.7 Da, as determined by mass spectrometry, and contained four Cys residues. Enzymatic hydrolysis followed by de novo sequencing by tandem mass spectrometry was used to determine the primary structure of the protein and the cysteine residues linked by disulfide bridges. The positions of 24 sequenced tryptic peptides, including the N-terminal, were deduced by comparison with a homologous protein from the superfamily Bombycoidea. Approximately 90% of the primary structure of the active protein was determined. Copyright © 2005 John Wiley & Sons, Ltd. [source] Enzymatic hydrolysis of Alaska pollack (Theragra chalcogramma) skin and antioxidant activity of the resulting hydrolysateJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 4 2010Jianping Jia Abstract BACKGROUND: Fish skin, a by-product of the food industry, contains a large amount of collagen. However, only a small proportion of fish skin is used in the production of leather materials and animal feedstuffs, most of it being discarded. The aims of this study were to prepare peptides from Alaska pollack (Theragra chalcogramma) skin by enzymatic hydrolysis and to evaluate the antioxidant activity of the resulting hydrolysate. RESULTS: Protamex was the most efficient enzyme for preparing antioxidant peptides from Alaska pollack skin. The optimal hydrolysis conditions were as follows: hydrolysis time 8 h; enzyme/substrate ratio 2:1000; skin/water ratio 1:6; temperature 55 °C; pH 6.0. Under these conditions the highest yield of peptides was 83.44%, with 85.95% of the hydrolysate being mainly composed of oligopeptides with molecular weights ranging from 180 to 1000 Da. The hydrolysate showed 2,2-diphenyl-1-picrylhydrazyl radical-scavenging activity, with an IC50 value of 2.5 mg mL,1, and its reducing power was 0.14 at 1 mg mL,1, 53.8% of that of reduced glutathione at the same concentration. CONCLUSION: This study demonstrated that the hydrolysate of Alaska pollack skin was mainly composed of oligopeptides with two to eight amino acid residues and possessed antioxidant activity. Copyright © 2010 Society of Chemical Industry [source] Effect of enzymatic hydrolysis of proteins on growth of Bifidobacterium bifidus in milkJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 5 2002V Vijaya Abstract The effect of enzymatic hydrolysis of proteins in milk using neutrase on the growth of the probiotic strain Bifidobacterium bifidus was evaluated by estimation of microbial growth, acidity, viscosity and flavour production. A significant increase in the growth of B bifidus was observed in neutrase-hydrolysed milk. The setting time of bifidus-cultured milk was advanced by about 12,h at 5% degree of hydrolysis. Enzymatic hydrolysis of proteins prior to cultivation also significantly increased the viscosity of the product. An approximately 60% increase in viscosity of the product was observed in neutrase-hydrolysed milk. Production of steam-volatile monocarbonyls as an indication of development of flavour was also higher in neutrase-hydrolysed milk. The concentration of steam-volatile monocarbonyls was 2.47,µmol per 100,ml in neutrase-hydrolysed milk but only 1.84,µmol per 100,ml in control milk at the setting point of the curd. © 2002 Society of Chemical Industry [source] Potentials of ion trap collisional spectrometry for liquid chromatography/electrospray ionization tandem mass spectrometry determination of buprenorphine and nor -buprenorphine in urine, blood and hair samplesRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 8 2006Donata Favretto A liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) method has been developed for the analysis of buprenorphine (BUP) and nor -buprenorphine (NBUP) in biological fluids. Analytes are isolated from urine and blood, after addition of d4 -buprenorphine (d4 -BUP) as internal standard, by solid-phase extraction. Preparation of hair involves external decontamination, mechanical pulverization, overnight incubation in acidic medium, and neutralization prior to extraction. Enzymatic hydrolysis with , -glucuronidase may be performed to distinguish between free and total BUP. Chromatographic separation is accomplished by gradient elution on a cyanopropyl 2.1,×,150,mm column. Positive ion ESI and MS analyses are carried out in an ion trap mass spectrometer. The use of this mass analyzer allows effective collisional experiments to be performed on ESI-generated MH+ species. Abundant product ions are produced, which can be monitored together with precursor ions without losing sensitivity. Thus, assay selectivity is definitely increased with respect to LC/ESI-MS/MS methods in which only precursor ions are monitored. The method has good linearity (calibration curves were linear in the range 0.1,10,ng/mL in urine and blood, in the range 10,160,pg/mg in hair) and limits of detection of 0.05,ng/mL for both BUP and NBUP in blood and urine samples, of 4,pg/mg for both analytes in hair. Both intra- and inter-assay precision and accuracy were satisfactory at three concentrations studied: relative standard deviations were <13.7% in urine, <17.3% in blood, <17.8% in hair; percent deviation of the mean from the true value was always <10.5% in urine and blood, <16.1% in hair. The method can be used to determine both analytes in the urine and hair of drug addicts on replacement therapy, and in post-mortem blood specimens when there is suspicion of drug-related death. Copyright © 2006 John Wiley & Sons, Ltd. [source] Quantification of acetylcholine, an essential neurotransmitter, in brain microdialysis samples by liquid chromatography mass spectrometryBIOMEDICAL CHROMATOGRAPHY, Issue 1 2010Ramakrishna Nirogi Abstract Chemical neurotransmission has been the subject of intensive investigations in recent years. Acetylcholine is an essential neurotransmitter in the central nervous system as it has an effect on alertness, memory and learning. Enzymatic hydrolysis of acetylcholine in the synaptic cleft is fast and quickly metabolizes to choline and acetate by acetylcholinesterase. Hence the concentration in the extracellular fluid of the brain is low (0.1,6,nm). Techniques such as microdialysis are routinely employed to measure acetylcholine levels in living brain systems and the microdialysis sample volumes are usually less than 50,µL. In order to develop medicine for the diseases associated with cognitive dysfunction like mild cognitive impairment, Alzheimer's disease, schizophrenia and Parkinson's disease, or to study the mechanism of the illness, it is important to measure the concentration of acetylcholine in the extracellular fluid of the brain. Recently considerable attention has been focused on the development of chromatographic,mass spectrometric techniques to provide more sensitive and accurate quantification of acetylcholine collected from in-vivo brain microdialysis experiments. This review will provide a brief overview of acetylcholine biosynthesis, microdialysis technique and liquid chromatography mass spectrometry, which is being used to quantitate extracellular levels of acetylcholine. Copyright © 2009 John Wiley & Sons, Ltd. [source] Potential of agroindustrial waste from olive oil industry for fuel ethanol productionBIOTECHNOLOGY JOURNAL, Issue 12 2007Tania I. Georgieva Abstract Olive pulp (OP) is a highly polluting semi-solid residue generated from the two-stage extraction processing of olives and is a major environmental issue in Southern Europe, where 80% of the world olive oil is produced. At present, OP is either discarded to the environment or combusted with low calorific value. In this work, utilization of OP as a potential substrate for production of bioethanol was studied. Enzymatic hydrolysis and subsequent glucose fermentation by baker's yeast were evaluated for OP from 10% to 30% dry matter (i.e., undiluted). Enzymatic hydrolysis resulted in an increase in glucose concentration by 75%, giving final glucose yields near 70%. Fermentation of undiluted OP hydrolysate (OPH) resulted in the maximum ethanol produced (11.2 g/L) with productivity of 2.1 g/L/h. Ethanol yields were similar for all tested OPH concentrations and were in the range of 0.49-0.51 g/g. Results showed that yeast could effectively ferment OPH even without nutrient addition, revealing the tolerance of yeast to OP toxicity. Because of low xylan (12.4%) and glucan (16%) content in OP, this specific type of OP is not a suitable material for producing only ethanol and thus, bioethanol production should be integrated with production of other value-added products. [source] Pretreatment of hybrid poplar by aqueous ammoniaBIOTECHNOLOGY PROGRESS, Issue 2 2009Rajesh Gupta Abstract Enzymatic hydrolysis of hybrid poplar treated by ammonia recycle percolation (ARP) was studied applying cellulase enzyme supplemented with additional xylanase or pectinase. The effect of xylanase addition was much more significant than pectinase addition. Conversion of ARP-treated hybrid poplar to ethanol was carried out by simultaneous saccharification and fermentation (SSF) and SS and cofermentation (SSCF). The maximum ethanol yield observed from the SSCF experiment was 78% of theoretical maximum based on the total carbohydrate (glucan + xylan). The same feedstock was also treated by soaking in aqueous ammonia (SAA), a batch pretreatment process with lower severity than ARP. The test results indicated that relatively high severity is required to attain acceptable level of digestibility of hybrid poplar. In order to lower the severity of the pretreatment, addition of H2O2 was attempted in the SAA. Addition of H2O2 significantly enhanced delignification of hybrid poplar due to its oxidative degradation of lignin. Several different H2O2 feeding schemes and different temperature profiles were attempted in operation of the SAA to investigate the effects of H2O2 on degradation of lignin and carbohydrates in hybrid poplar. More than 60% of lignin in hybrid poplar was removed with stepwise-increase of temperature (60,120°C after 4h of reaction). Increase of carbohydrate degradation was also observed under this condition. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009 [source] Enzymatic Hydrolysis of Waste Office Paper Using Viscosity as Operating ParameterBIOTECHNOLOGY PROGRESS, Issue 2 2001Enoch Y. Park Enzymatic hydrolysis of waste office (WO) paper with feeding WO paper in a reactor was investigated using apparent viscosity as operating parameter. Since the apparent viscosity was correlated with the concentration of pulping WO paper, the amount of hydrolyzed WO paper was assumed by measuring the decrease in the apparent viscosity. Then the amount of hydrolysis WO paper and the amount of enzyme corresponding to the desired ratio were fed into the reactor. When the WO paper and 1% (to the amount of WO paper) enzyme were fed to the hydrolytic reaction, 87 g/L of reducing sugar (RS) with a hydrolytic yield of 42.2% was obtained for a 24-h hydrolysis. However, when nonpulping WO paper and 5% (to the amount of WO paper) enzyme were fed to the hydrolytic reaction, 120 g/L of RS with a hydrolytic yield of 40% was obtained for a 24-h hydrolysis. Therefore, the RS concentration from this hydrolysis process feeding WO paper using apparent viscosity as operating parameter may be of sufficient concentration to serve as a carbon source in microorganism culture or chemical feedstock. [source] Direct injection horse-urine analysis for the quantification and confirmation of threshold substances for doping control.DRUG TESTING AND ANALYSIS, Issue 8 2009Abstract Levodopa and dopamine have been abused as performance-altering substances in horse racing. Urinary 3-methoxytyramine is used as an indicator of dopaminergic manipulation resulting from dopamine or levodopa administration and is prohibited with a urinary threshold of 4 µg mL,1 (free and conjugated). A simple liquid chromatographic (LC)/mass spectrometric (MS) (LCMS) method was developed and validated for the quantification and identification of 3-methoxytyramine in equine urine. Sample preparation involved enzymatic hydrolysis and protein precipitation. Hydrophilic interaction liquid chromatography (HILIC) was selected as a separation technique that allows effective retention of polar substances like 3-methoxytyramine and efficient separation from matrix compounds. Electrospray ionization (ESI) in positive mode with product ion scan mode was chosen for the detection of the analytes. Quantification of 3-methoxytyramine was performed with fragmentation at low collision energy, resulting in one product ion, while a second run at high collision energy was performed for confirmation (at least three abundant ions). Studies on matrix effects showed ion suppression depending on the horse urine used. To overcome the variability of the results originating from the matrix effects, isotopic labelled internal standard was used and linear regression calibration methodology was applied for the quantitative determination of the analyte. The tested linear range was 1,20 µg mL,1. The relative standard deviations of intra- and inter- assay analysis of 3-methoxytyramine in horse urine were lower than 4.2% and 3.2%, respectively. Overall accuracy (relative percentage error) was less than 6.2%. The method was applied to case samples, demonstrating simplicity, accuracy and selectivity. Copyright © 2009 John Wiley & Sons, Ltd. [source] The Composition of Jerusalem Artichoke (Helianthus tuberosus L.) Spirits Obtained from Fermentation with Bacteria and YeastsENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 1 2005K. Szambelan Abstract The composition of spirits distilled from fermentation of Jerusalem artichoke (Helianthus tuberosus L.) tubers was compared by means of gas chromatography. The microorganisms used in the fermentation processes were the bacterium Zymomonas mobilis, strains,3881 and 3883, the distillery yeast Saccharomyces cerevisiae, strains,Bc16a and D2 and the Kluyveromyces fragilis yeast with an active inulinase. The fermentation of mashed tubers was conducted using a single culture of the distillery yeast Saccharomyces cerevisiae and the bacterium Zymomonas mobilis (after acid or enzymatic hydrolysis) as well as Kluyveromyces fragilis (sterilized mashed tubers). The tubers were simultaneously fermented by mixed cultures of the bacterium or the distillery yeast with K.,fragilis. The highest ethanol yield was achieved when Z.,mobilis,3881 with a yeast demonstrating inulinase activity was applied. The yield reached 94,% of the theoretical value. It was found that the distillates resulting from the fermentation of mixed cultures were characterized by a relatively lower amount of by-products compared to the distillates resulting from the single species process. Ester production of 0.30,2.93,g/L, responsible for the aromatic quality of the spirits, was noticed when K.,fragilis was applied for ethanol fermentation both in a single culture process and also in the mixed fermentation with the bacterium. Yeast applied in this study caused the formation of higher alcohols to concentrations of 7.04,g/L much greater than those obtained with the bacterium. The concentrations of compounds other than ethanol obtained from Jerusalem artichoke mashed tubers, which were fermented by Z.,mobilis, were lower than those achieved for yeasts. [source] Thermophilic anaerobes in Arctic marine sediments induced to mineralize complex organic matter at high temperatureENVIRONMENTAL MICROBIOLOGY, Issue 4 2010Casey Hubert Summary Marine sediments harbour diverse populations of dormant thermophilic bacterial spores that become active in sediment incubation experiments at much higher than in situ temperature. This response was investigated in the presence of natural complex organic matter in sediments of two Arctic fjords, as well as with the addition of freeze-dried Spirulina or individual high-molecular-weight polysaccharides. During 50°C incubation experiments, Arctic thermophiles catalysed extensive mineralization of the organic matter via extracellular enzymatic hydrolysis, fermentation and sulfate reduction. This high temperature-induced food chain mirrors sediment microbial processes occurring at cold in situ temperatures (near 0°C), yet it is catalysed by a completely different set of microorganisms. Using sulfate reduction rates (SRR) as a proxy for organic matter mineralization showed that differences in organic matter reactivity determined the extent of the thermophilic response. Fjord sediments with higher in situ SRR also supported higher SRR at 50°C. Amendment with Spirulina significantly increased volatile fatty acids production and SRR relative to unamended sediment in 50°C incubations. Spirulina amendment also revealed temporally distinct sulfate reduction phases, consistent with 16S rRNA clone library detection of multiple thermophilic Desulfotomaculum spp. enriched at 50°C. Incubations with four different fluorescently labelled polysaccharides at 4°C and 50°C showed that the thermophilic population in Arctic sediments produce a different suite of polymer-hydrolysing enzymes than those used in situ by the cold-adapted microbial community. Over time, dormant marine microorganisms like these are buried in marine sediments and might eventually encounter warmer conditions that favour their activation. Distinct enzymatic capacities for organic polymer degradation could allow specific heterotrophic populations like these to play a role in sustaining microbial metabolism in the deep, warm, marine biosphere. [source] Polysaccharide hydrolysis in aggregates and free enzyme activity in aggregate-free seawater from the north-eastern Gulf of MexicoENVIRONMENTAL MICROBIOLOGY, Issue 2 2008Kai Ziervogel Summary Marine snow aggregates represent hotspots of carbon remineralization in the ocean. Various aspects of bacterial dynamics have been investigated on marine snow. To date, extracellular enzymatic activities in aggregates have been measured using small substrate proxies that do not adequately reflect the complexity of biomacromolecules such as polysaccharides, proteins and lipids. To address this issue, we used six structurally distinct, fluorescently labelled polysaccharides to measure enzymatic hydrolysis on aggregates formed with a roller table and in aggregate-free (ambient) seawater from two near-coast sites, north-eastern Gulf of Mexico. A single polysaccharide was incubated in aggregates and ambient seawater. Changes in polysaccharide molecular weight were monitored over time to measure the course of enzymatic hydrolysis. All six polysaccharides were hydrolysed in aggregates, indicating a broad range of enzyme activities in aggregate-associated bacteria. Four substrates were also hydrolysed in ambient waters. Epifluorescence microscopy revealed that nearly all of the bacteria present in original waters were incorporated into aggregates. Therefore hydrolytic activities in ambient waters were presumably due to enzymes spatially disconnected from cells and aggregates. Our results show substantial enzymatic activity in cell/aggregate-free seawater, suggesting a significant role of free enzymes in hydrolytic activity in waters from the north-eastern Gulf of Mexico. [source] Bioethanol from agricultural waste residuesENVIRONMENTAL PROGRESS & SUSTAINABLE ENERGY, Issue 1 2008Pascale Champagne Abstract Under the Kyoto Protocol, the Government of Canada has committed to reducing its greenhouse gas emissions by 6% from 1990 levels between 2008 and 2012. Ethanol-blended gasolines have the potential to contribute significantly to these emission reductions. Ethanol is derived from biologically renewable resources and can be employed to replace octane enhancers and aromatic hydrocarbons or oxygenates. To date, the ethanol production industry in Canada is comprised mainly of small-scale plants producing ethanol primarily from agricultural crops as feedstock. Research interests in the area of bioethanol production from organic waste materials emerged in the late 1980. Significant advances in lignocellulosic material extraction and enzymatic hydrolysis have been reported in the last decade, however, continued research efforts are essential for the development of technically feasible and economically viable large-scale enzyme-based biomass-to-ethanol conversion processes. This research aims to develop and test an enzyme-based biomass-to-ethanol conversion process, which employs organic waste materials, such as livestock manures, as alternative sources of cellulosic material feedstock. The source of the livestock manure, manure management practices and cellulose extraction procedures have a significant impact on the quantity and quality of the cellulosic materials derived. As such, raw feedstock materials must be carefully characterized to assess the impact of these factors on the yield of bioethanol and residual end products. The success of cellulose-to-ethanol conversion processes for cellulose extracted from these waste materials as feedstock is generally a function of cellulose fiber pretreatment, enzyme selection and operating conditions. These will differ depending on the source of the waste material feedstock. The long-term benefits of this research will be to introduce a sustainable solid waste management strategy for a number of livestock manure and other lignocellulosic waste materials; contribute to the mitigation in greenhouse gases through sustained carbon and nutrient recycling; reduce the potential for water, air, and soil contamination associated with land disposal of organic waste materials; and to broaden the feedstock source of raw materials for the ethanol production industry. © 2007 American Institute of Chemical Engineers Environ Prog, 2008 [source] Biological measurement of estrogenic activity in urine and bile conjugates with the in vitro ER-CALUX reporter gene assayENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2002Juliette Legler Abstract Although estrogens are excreted as biologically inactive conjugates, they can be reconverted to an active form, possibly by bacteria. A simple method was developed to deconjugate estrogen metabolites present in human urine and fish bile back to active estrogens by enzymatic hydrolysis with ,-glucuronidase or live Escherichia coli cells. Deconjugated extracts were tested for estrogenic activity in the in vitro stable estrogen receptor,mediated chemical-activated luciferase gene expression (ER-CALUX) assay. Estrogen glucuronides in urine obtained from human males and females were effectively converted to active forms after incubation with ,-glucuronidase or E. coli. The highest estrogenic activity was found in deconjugated metabolites from urine of a pregnant woman, in which levels up to 3,000 nmol estradiol equivalents per liter of urine were found after overnight incubation of urine with E. coli. Bile sampled from male bream and flounder from various freshwater and marine locations was also deconjugated and a good correlation was found between high biliary estrogenic activity and elevated levels of xenoestrogenic activity in surface water as well as in plasma vitellogenin. Therefore, the measurement of deconjugated bile could form a useful (indirect) biomarker for internal dose of xenoestrogens in male fish. [source] REVIEW FOR SPECIAL ISSUE ON CANNABINOIDS: Ligands that target cannabinoid receptors in the brain: from THC to anandamide and beyondADDICTION BIOLOGY, Issue 2 2008Roger G. Pertwee ABSTRACT A major finding,that (,)- trans -,9 -tetrahydrocannabinol (,9 -THC) is largely responsible for the psychotropic effects of cannabis,prompted research in the 1970s and 1980s that led to the discovery that this plant cannabinoid acts through at least two types of cannabinoid receptor, CB1 and CB2, and that ,9 -THC and other compounds that target either or both of these receptors as agonists or antagonists have important therapeutic applications. It also led to the discovery that mammalian tissues can themselves synthesize and release agonists for cannabinoid receptors, the first of these to be discovered being arachidonoylethanolamide (anandamide) and 2-arachidonoylglycerol. These ,endocannabinoids' are released onto their receptors in a manner that appears to maintain homeostasis within the central nervous system and sometimes either to oppose or to mediate or exacerbate the unwanted effects of certain disorders. This review provides an overview of the pharmacology of cannabinoid receptors and their ligands. It also describes actual and potential clinical uses both for cannabinoid receptor agonists and antagonists and for compounds that affect the activation of cannabinoid receptors less directly, for example by inhibiting the enzymatic hydrolysis of endocannabinoids following their release. [source] Enzymatic fatty acid exchange in glycero-phospholipids,EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 10 2003Patrick Adlercreutz Abstract Lipases can be used to exchange fatty acids in the sn -1 position of glycerophospholipids and phospholipase A2 is useful for the corresponding exchange reaction in the sn -2 position. In both cases, the exchange can be done in a one-step acidolysis process or in a two-step process. In the latter case, the original fatty acid in the desired position is removed by enzymatic hydrolysis or alcoholysis and after isolation of the resulting lysophospholipid, the new fatty acid is introduced, using the same enzyme, in an esterification reaction. Several synthesis examples from the literature are reviewed. Incorporation of a new fatty acid into the sn -1 position is more favourable than incorporation into the sn -2 position because of the magnitudes of the equilibrium constants of the reactions and because lipases can be used at much lower water activity than phospholipase A2. With the consecutive use of both enzymes highly pure products with defined fatty acids in both positions can be obtained. [source] Novel polysialogangliosides of skate brainFEBS JOURNAL, Issue 16 2000Structural determination of tetra, hexasialogangliosides with a NeuAc-GalNAc linkage, penta The gangliosides in the brain of a cartilaginous fish, skate (Bathyraja smirnovi), have been isolated and characterized by means of methylation analysis, antibody binding, enzymatic hydrolysis and MALDI-TOF MS. In addition to gangliosides with known structures (GM2, fucosyl-GM1, GD3, GD2, GT3 and GT2), five polysialogangliosides were isolated and characterized as having the following structures. (1) IV3NeuAc, III6NeuAc, II3NeuAc-Gg4Cer; (2) IV3NeuAc2, III6NeuAc, II3NeuAc-Gg4Cer; (3) IV3NeuAc, III6NeuAc, II3NeuAc2 -Gg4Cer; (4) IV3NeuAc, III6NeuAc, II3NeuAc3 -Gg4Cer; and (5) IV3NeuAc2, III6NeuAc, II3NeuAc3 -Gg4Cer. These structures are ,hybrid-type' which comprise combinations of ,-series and either a, b or c-series structures. Three gangliosides (2), (4) and (5), were novel. The main features of the ganglioside composition of skate brain were an abundance of gangliotriaosyl species, a lack of gangliotetraosyl species (except fucosyl-GM1), and an abundance of hybrid-types. These characteristics closely resemble those in shark brain which we reported previously [Nakamura, K., Tamai, Y. & Kasama, T. (1997) Neurochem. Int.30, 593,604]. Two of the hybrid-type gangliosides (1) and (4), were examined for their neuritogenic activity toward cultured neuronal cells (Neuro-2A), and were found to have more potent activity than nonhybrid-type gangliosides such as GM1. [source] Enhanced exoenzyme activities in sediments in the presence of deposit-feeding Chironomus riparius larvaeFRESHWATER BIOLOGY, Issue 9 2007PETER STIEFArticle first published online: 10 JUN 200 Summary 1. The combined effects of deposit-feeding, bioturbation and bioirrigation by benthic macrofauna on the enzymatic hydrolysis of organic matter were studied in microcosms. Chironomus riparius larvae (Insecta, Diptera) served as model macrofauna and stinging nettle leaves (Urtica dioica) were used as a detrital food source. 2. In the upper 10 mm of the sediment (the habitat of C. riparius larvae), the activities of several exoenzymes, the contents of several fractions of particulate organic matter (POM), and the concentrations of dissolved oxidants (O2, NO) were measured on a small scale. Fluorescent particles (luminophores) were used to quantify the vertical redistribution of particles within the same layer. 3. In control sediment, the addition of detrital food enhanced exoenzyme activities in the 0,2 mm layer only. In the presence of C. riparius larvae, exoenzyme activities increased to 10 mm depth. Further, the content of POM in the 0,2 mm layer was lower in the presence than in the absence of larvae, suggesting ingestion and subduction of the added detritus. After prolonged incubation without further food addition, exoenzyme activities returned close to background values in both treatments, whereas the vertical distribution of POM remained unchanged. 4. The overall penetration depth of O2 and NO into the sediment was greater in the presence than the absence of C. riparius, the differences being more pronounced after prolonged incubation. Locally high O2 and NO concentrations due to bioirrigation by C. riparius were measured deep in the sediment. Net downward transport of particles was observed only in the presence of C. riparius larvae and only at the beginning of the incubation. 5. I conclude that deposit-feeding and bioturbation by macrofauna can quickly remove freshly deposited POM from the sediment surface and transfer it to less oxygenated sites (i.e. animal guts and deep sediment layers). Bioirrigation also increases the availability of oxidants deep in the sediment. The oscillation of oxidant supply to POM particles by ingestion,egestion, burial and re-burial, and the intermittent bioirrigation of subsurface sediment, is probably the cause of the increased rate of organic matter hydrolysis, the rate-limiting step in mineralization. [source] Glucuronidation of olanzapine by cDNA-expressed human UDP-glucuronosyltransferases and human liver microsomesHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 5 2002Kristian Linnet Abstract Olanzapine is a widely used, newer antipsychotic agent, which is metabolized by various pathways: hydroxylation and N -demethylation by cytochrome P450, N -oxidation by flavin monooxygenase and direct glucuronidation. In vivo studies have pointed towards the latter pathway as being of major importance. Accordingly, the glucuronidation reaction was studied in vitro using cDNA-expressed human UDP-glucuronosyltransferase (UGT) enzymes and a pooled human liver microsomal preparation (HLM). Glucuronidated olanzapine was determined by HPLC after acid or enzymatic hydrolysis. The following UGT-isoenzymes were screened for their ability to glucuronidate olanzapine: 1A1, 1A3, 1A4, 1A6, 1A9, 2B7 and 2B15. Only UGT1A4 was able to glucuronidate olanzapine obeying saturation kinetics. The Km value was 227,,mol/l (SE 43), i.e. of the same order of magnitude as for other psychotropic drugs, and the Vmax value was 2370,pmol/(min,mg) (SE 170). Glucuronidation was also mediated by the HLM preparation, but a saturation level was not reached. The olanzapine glucuronidation reaction was inhibited by several drugs known as substrates for UGT1A4, e.g. amitriptyline, trifluoperazine and lamotrigine. Thus, competition for glucuronidation by UGT1A4 represents a possibility for drug,drug interactions in subjects receiving several of these psychotropic drugs at the same time. Whether such possible interactions are of any clinical importance may await further studies in patients. Copyright © 2002 John Wiley & Sons, Ltd. [source] Collagenous hydrolysates from untraditional sources of proteins.INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 4 2001Reaction condition, the yield of enzymatic hydrolysis of short cattle tendons Synopsis The effect of reaction conditions on the yield of enzymatic hydrolysis of short cattle tendons was examined using statistical scheme of factorial experiments 24. The duration of enzymatic purification of the starting material and of purified material denaturation processes, the protease concentration in reaction mixture and hydrolysis time were considered to be the main sources of reaction yield variation. An attempt was made to find the conditions leading to maximal yield of collagen hydrolysate. Résumé On a étudié l'effet des conditions de réaction sur le rendement de l'hydrolyse enzymatique de tendons courts de bétail en utilisant un plan d'expériences statistique de factorielle 24. On a considéré que la durée de la purification enzymatique du produit de départ et des processus de dénaturation du matériau purifié, la concentration en protéase dans le mélange réactionnel et le temps d'hydrolyse étaient les paramètres majeurs de variation du rendement de réaction. On a effectué un essai de résolution des conditions conduisant au rendement maximal en hydrolysat de collagène. [source] | ||||||||||||||||||||||||||||||||||||||||