Search

Two simple and easily reproducible methods for the immobilization of β-galactosidase (β-gal) from Aspergillus oryzae on electrospun gelatin nanofiber mats (GFM) were developed. The process was optimized regarding the electrospinning solvent system and the subsequent cross-linking of GFM in order to increase their stability in water. β-Gal was covalently immobilized on activated gelatin nanofiber mats with hexamethylenediamine (HMDA) as a bifunctional linker and secondly via entrapment into the gelatin nanofibers during the electrospinning process (suspension electrospinning). Optimal immobilization parameters for covalent immobilization were determined to be at pH 7.5, 40 °C, β-gal concentration of 1 mg/mL and immobilization time of 24.5 h. For suspension electrospinning, the optimal immobilization parameters were identified at pH 4.5 and β-gal concentration of 0.027 wt.% in the electrospinning solution. The pH and temperature optima of immobilized β-gal shifted from 30 °C, pH 4.5 (free enzyme) to pH 3.5, 50 °C (covalent immobilization) and pH 3.5, 40 °C (suspension electrospinning). Striking differences in the Michaelis constant (KM) of immobilized β-gal compared with free enzyme were observed with a reduction of KM up to 50% for immobilized enzyme. The maximum velocity (vmax) of immobilization by suspension electrospinning was almost 20 times higher than that of covalent immobilization. The maximum GOS yield for free β-gal was found to be 27.7% and 31% for immobilized β-gal.

Bienzymatic production of laminaribiose from sucrose and glucose was combined with adsorption on zeolite BEA to introduce a first capture and purification step. Downstream processing including washing and desorption steps was characterized and optimized on a milliliter scale in batch mode. Results were then transferred to a packed bed system for enzymatic production and adsorption where the influence of adsorbent particle diameter on purity and productivity was evaluated. Finally, a continuous enzymatic production of laminaribiose was conducted over 10 days. The subsequent downstream processing of the loaded zeolites led to purities of over 0.5 g(Laminaribiose) g(sugar) (−1) in the desorbate with a total productivity of 5.6 mg(Laminaribiose) L(enzyme bed) (−1) h(−1) without the use of recycles.

The first continuous production system of laminaribiose from sucrose and glucose in a bienzymatic reaction is reported in this study. Immobilized laminaribiose phosphorylase and sucrose phosphorylase were used in a packed bed reactor system comprising of a 3-cm glass column at 35 °C with a steady feeding flow rate of 0.1 ml/min. Factors affecting product formation including enzyme ratio, peal concept (both enzymes in one pearl or in separate pearls), and pearl size were studied. An enzyme ratio of 2:1 of laminaribiose phosphorylase (LP) to sucrose phosphorylase (SP) when encapsulated separately in bigger size peals resulted in higher concentration of product. Laminaribiose (0.4 g/(L h)) is produced in the optimized system at steady state. The reaction system proved to be operationally stable throughout 10 days of continuous processing. A half-life time of more than 9 days was observed for both biocatalysts.

Commercial application of biocatalysts depends on the efficiency of the immobilization method and residual enzyme activity. Electrospinning offers a simple and versatile route to immobilize enzymes in submicron-sized fibers and thus improved mass transfer characteristics. Performance of encapsulation of fructosyltransferase from Bacillus subtilis by emulsion, suspension, and coaxial electrospinning was compared. We particularly focused on the effect of hydrophilic properties of a set of biodegradable polymers on support’s activity. Bioactivity of electrospun support in aqueous medium increased in order of the matrix hydrophilicity. Additionally, the efficiency of electrospun fibers was compared with Sepabeads®, commercial epoxy-activated resins. In fibers, enzyme loading of 68.1 mg/g and specific enzyme activity of 5.5 U/mg was achieved compared to 49.5 mg/g and 2.2 U/mg on Sepabeads. Fructosyltransferase exhibited high sensitivity towards organic solvents and covalent attachment, respectively. Immobilization of native enzyme in coaxial fibers increased the specific activity to approx. 30 U/mg which corresponds to 24% of that of the free enzyme. Finally, operational stability of fiber supports was examined in a plug-flow reactor and 5% of initial substrate conversion remained after > 2000 cycles. The efficiency of core-shell immobilizates compared to one-dimensional fibers was both in batch and continuous reaction at least 4.4-fold higher.

A hybrid-immobilization method was developed to improve the long-term stability of laminaribiose phosphorylase immobilized on epoxy supports Sepabeads EC-EP/S. Entrapment in chitosan retained all of the enzyme activity depending on the amount of entrapped solid materials and increased half-life by a factor of 10-94.4 h. No enzyme activity loss was determined during 12 times reuse. The immobilization method is also applicable to sucrose phosphorylase immobilized on Sepabeads EC-EP/S. Up to 31.9 g/L laminaribiose were produced in bienzymatic batch experiments with reaction-integrated product separation by adsorption on zeolites.

Laminaribiose phosphorylase (EC 2.4.1.31) catalyzes a reversible phosphorolysis reaction in which laminaribiose, a very high value sugar is produced. This enzyme is not being produced commercially therefore, to realize the most effective method for producing laminaribiose phosphorylase and obtaining as much activity units as possible per liter of culture, different cultivation methods of Euglena gracilis were compared. Heterotrophic and mixotrophic cultivations of Euglena gracilis in two different pHs, in flask and bioreactor were performed. The reverse phosphorolysis activity of laminaribiose phosphorylase produced under different cultivation methods was measured. The heterotrophic approach showed to be the more effective cultivation method as 47.6 IU/L was obtained compared to 27 IU/L in the mixotrophic one. The heterotrophic cultivation then was further investigated under two different pH values of the culture media. The culture at pH 6.8 resulted in 7.94 IU/L/day whereas only 4.06 was obtained for the culture at pH 4. Cultivation in a bioreactor resulted in a distinctive amount of 191.5 IU/L and an activity yield of 9.7 IU/g glucose compared to 5.4 in flask cultivation. Heterotrophic cultivation of Euglena gracilis in a bioreactor containing a culture media at pH 6.8 and controlled operation conditions showed enhanced laminaribiose phosphorylase activity production per liter and day of cultivation.

The most significant drawback of bacterial protein production involving inclusion bodies is the subsequent refolding into bioactive form. Implementation of refolding operations in large-scale applications often fails due to low yields and/or low product concentrations. This paper presents a simple method of integrated refolding by dialysis and matrix assisted refolding that combines advantages of both methods, high product concentrations and high refolding yields. Ion exchange resins (IER) and size exclusion media served as refolding additives and were added to solubilized protein prior to refolding by continuous exchange of dialysis buffer. Refolding experiments were performed with fructosyltransferase (FTF, EC 2.4.1.162) from Bacillus subtilis NCIMB 11871 produced as inclusion bodies. Conventional anion exchangers with gel matrix structure enhanced refolding performance by about 43% with final protein concentration of 9 mg/mL and yield improvement is strictly linear dependent on the mass ratio of resins to protein. With the applied setup refolded protein was self-eluted from resin due to pH and salt concentration shift during dialysis. Macroporous resins and gel filtration media showed a negative effect on refolding yields.

For commercial applications refolding process must be fast, inexpensive and highly efficient. In the past many strategies for protein refolding were introduced. Still, simple refolding methods with high product concentrations are still rare. Refolding experiments were performed with fructosyltransferase (FTF, EC 2.4.1.162) from Bacillus subtilis NCIMB 11871 produced as inclusion bodies. Solubilizates were refolded with batch dialysis or by continuous exchange of dialysis buffers with variable ionic strength. By employing dialysis with gentle removal of denaturant the dependence of protein concentration and decreasing refolding yields could be overcome compared to batch dialysis and yields were enhanced by 52% at protein concentrations of approx. 10 mg/mL. The average specific activity of refolded FTF was 123 U/mg, 83% relative to standard FTF. Rising ionic strength of refolding buffers to 600 mM leads to complete renaturation of solubilized protein at equal protein concentration. Buffer composition plays a less significant role on renaturation output. The effect might be correlated with ion charge density of co-solvents.

A major problem in anaerobic waste-water treatment results from difficulties with the mixing of sludge, when it has settled after periods of standstill. A new method for reactivating those plants is discussed in this paper. In a technical anaerobic plant (volume 9600 m3) a control problem led to a breakdown of the process, connected with a drastic increase of the reactor COD. The load to the reactor was temporarily stopped to remove the inhibiting conditions. Restart with low loading rates and addition of new sludge did not lead to the expected increase in performance. The main problem was to suspend the sludge layer, which was settled on the bottom of the reactor. For activating the sludge layer feed “shots” were added up to three times per day. These shots consisted of volume streams of high loaded waste-water, up to five times bigger than the normal stream at that time and lasting for 1 h. The shots provided the sludge layer much better with substrate and caused biogas formation which itself led to a suspension of bacterial flocs. The same strategy was applied again successfully for reactivating a second anaerobic 10,000 m3 reactor.

Ausgehend von drei individuellen enzymatischen Kinetiken sowie von Gleichgewichtsdaten aus Reinstoffmessungen wurde eine Simulation fur die reaktionsintegrierte Adsorption von trienzymatisch produzierter Laminaribiose erstellt. Dabei steigert eine diskontinuierliche Uberlagerung von Reaktion und Adsorption die Ausbeute um ein Drittel. Fur eine kontinuierliche Adsorption mit zyklischem Ausschleusen des beladenen und Ersatz durch frisches Adsorbens lasst sich die Ausbeute sogar um das 2,4fache steigern. Ein zu kurzer Austauschzyklus des Adsorbens fuhrt jedoch zum Austrag von Intermediaten, so dass weniger Produkt gebildet wird. A simulation for the reaction integrated adsorption of trienzymatic synthesized laminaribiose was created, based on three individual enzymatic kinetics and equilibrium data from pure substance measurements. A discontinuous integration of reaction and adsorption was able to increase the yield by one third. A continuous adsorption with a cyclic transfer of loaded and replacement with fresh adsorbent can increase the yield by even 2.4 times. However, if the replacement cycle of the adsorbent is too short, the discharge of intermediates results in a reduced product formation.

Immobilization methods and carriers were screened for immobilization of Euglena gracilis extract with laminaribiose phosphorylase activity. The extract was successfully immobilized on three different carriers via covalent linkage. Suitable immobilization carriers were Sepabeads EC-EP/S and ECR 8209M with epoxy groups and ECR 8309M with amino groups as functional units. Immobilization on Sepabeads EC-EP/S resulted in highest retained activity (65%). The immobilizates were characterized for pH, temperature, and buffer molarity preferences. The immobilized enzyme lost 48% of its activity when used seven times. Together with sucrose phosphorylase, laminaribiose phosphorylase was successfully applied for bienzymatic production of laminaribiose from sucrose and glucose with a final laminaribiose concentration of 14.3 ± 2.1 g/L (20% yield).

A new genetically derived variant of the glucosyltransferase from Streptococcus oralis has been characterized physicochemically and kinetically. Compared with the industrially used glucosyltransferase from Leuconostoc mesenteroides, the enzyme variant GTF-R S628D possesses 25 times higher affinity for the specific glucosylation of glucose. For a concept of integrated reaction and product isolation, a fluidized bed reactor with in situ product removal was applied. The technical feasibility and the applicability of the kinetic models for reaction and adsorption could be demonstrated. The immobilized enzyme was stable (20% activity loss after 192 h) and product could be obtained with 90% purity. A bioprocess model was generated which allowed the integral assessment of the enzymatic synthesis and in situ product adsorption. The model is a powerful tool which assists with the localization of optimal process parameters. It was applied for the process evaluation of other glucosyltransferases and demonstrated key characteristics of each enzymatic system.

This paper describes studies carried out into downstream processing for an enzymatic system producing isomaltose by glucosyltransfer, in which the isomaltose appears as an intermediate in a consecutive reaction chain. To avoid these consecutive reactions, reaction-integrated separation by adsorption was established. A specific β-zeolite was investigated as a selective adsorbent for the product isomaltose, and the influence of eluent and temperature on the desorption process was researched. As eluent, 50% (v/v) ethanol and pure water were compared. Using 50% ethanol the amount of desorbed isomaltose is about 23% higher than in pure water. In both cases desorption takes place over a period of more than 50 h and at a temperature of 70 °C. Residual moisture on zeolite significantly decreases adsorption capacity. In batch experiments, the half-life of zeolite stored in water is about 50 h, but for a continuous flow in a packed bed column, the half-life decreases to 7 h. Based on these findings, a design for downstream processing is proposed using a counter-current flow temperature swing displacement desorption sequence. Here, product concentration can be increased by multiple usage of the desorption liquid.

Co-Immobilization of dextransucrase (DS) and dextranase (DN) into calcium alginate includes the co-entrapment of soluble DS and adsorbed DN. DS converts sucrose into dextran, which is the substrate for DN, so that isomalto-oligosaccharides (IMOs) are follow-up products of dextran hydrolysis. The boundary conditions for the successful preparation are investigated with respect to choice of DN adsorbate, surface modifications using blotting agents and optimal enzyme activity ratios. Further, repetitive batch experiments suggest the selection of medium activity ratios for continuous use (0.3 U(DN)U(-1) (DS), e.g.). Product formation at various cosubstrate:substrate concentrations as well as at different DN:DS ratios are discussed. Moreover, the complexity of the bi-enzymatic system can be reduced considering the molar ratios of cosubstrate:substrate (glucose:sucrose). Based on these factors, a mechanistic kinetic model is developed, which distinguishes the corresponding contributions of the two enzymes upon overall product formation. In general, at low glucose:sucrose ratios isomaltose synthesis is featured primarily by DN action. Yet with increasing amounts of glucose both the quantity and quality of DN substrate changes, so that its contribution to product formation decreases in an exponential manner; still the overall product yield continuously increases due to enhanced DS contribution.

Es wird die Optimierung der Isomaltoseproduktion durch ein System aus enzymkatalysierter Reaktion und Adsorption des Produkts untersucht. Dafur wurden die Reaktionsbedingungen, die Biokatalysatoreigenschaften sowie die reaktionsintegrierte Abtrennung des Produkts eingehend gepruft. Ausgehend von immobilisierter Dextransucrase als Biokatalysator konnte durch Entwicklung von Coimmobilisaten ein deutlicher Fortschritt erzielt werden. Das beste Ergebnis lies sich mit einer genetisch modifizierten Dextransucrase (GTFR) erhalten, wodurch die integrierte Abtrennung des Produkts bedeutend erleichtert wird. Der Gesamtprozess aus Biokatalyse und Adsorption fur die verschiedenen Modifikationen wurde durch Berechnung der Prozesseffizienzen evaluiert.

Fermentation kinetics of Penicillium aculeatum ATCC 10409 demonstrated that fungal growth and dextranase release are decoupled. Inoculation by conidia or mycelia resulted in identical kinetics. Two new isoenzymes of the dextranase were characterized regarding their kinetic constants, pI, MW, activation energy and stabilities. The larger enzyme was 3-fold more active (turnover number: 2,230 +/- 97 s(-1)). Pre-treatment of bentonite with H(2)O(2) did not affect adsorption characteristics of dextranase. Enzyme to bentonite ratios above 0.5:1 (w/w) resulted in a high conservation of activity upon adsorption. Furthermore, dextranase could be used in co-immobilizates for the direct conversion of sucrose into isomalto-oligosaccharides (e.g. isomaltose). Yields of co-immobilizates were 2-20 times that of basic immobilizates, which consist of dextransucrase without dextranase.

This work focuses on the implementation of high performance systems to the wastewater treatment of sugar factories. For this purpose, systems with immobilised bacteria were studied. For the hydrolysis of organic matter and denitrification, fluidized bed reactors were used. The nitrification was studied with an airlift reactor system. Both hydrolysis and nitrogen elimination were investigated on laboratory and pilot scales in sugar factories. Although with porous materials higher biomass concentrations are attainable for the hydrolysis (up to 55 kg/m3), for economical reasons sand was used (22.5 kg/m3) for the pilot scale-study. With a pilot-scale reactor (volume 1 m3) the maximum sucrose conversion rate achieved with sand in the first campaign was 52 kg/(m3 d). For the nitrogen elimination on the pilot scale, a system with denitrification and nitrification was combined. The highest performance for the nitrification (reactor volume: 0.68 m3) with pumice as support material was 1.2 kg NH4-N/(m3 d), limiting the whole system. The denitrification rate (reactor volume: 0.12 m3) was four times higher (3.5–5 kg NO3-N/(m3 d). Rules of the modelling of the system are discussed.

The acceptor reaction of dextransucrase from Leuconostoc mesenteroides NRRL-B512F with glucose as acceptor is of technical interest for isomaltooligosaccharide (IMOs) synthesis. Different experimental conditions were investigated for free and immobilized enzyme. The data for oligosaccharide formation up to a degree of polymerization 4 were correlated with a model developed earlier, and optimal reaction conditions for immobilized dextransucrase design and application were identified for later continuous application. Furthermore, stability was investigated for free and immobilized enzyme including stabilization by sugars.

The growing recognition of the roles of carbohydrates in fundamental biological processes and their potential application as functional foods and new therapeutics have generated a requirement for the general availability of larger amounts of varying carbohydrate structures.Thus the synthesis of oligo-, polysaccharides and glycosylated substances/products represents a major challenge.Activated sugars are key substrates for synthesis and glycosylation. Nucleotide activated sugars are natural tools for highly selective synthesis, providing complex polysaccharides, glycopeptides, glycolipids etc. However their high cost and availability limit their application. Sucrose acts as an activated substrate for a range of sucrase enzymes elaborating natural polysacchrides of the glucan and fructan type, which also serve for the synthesis and technical production of different oligosaccharides. Sucrose analogues have been shown to extend the range of oligosaccharide synthesis making new structures available incorporati...

Extracted sugar-beet pulp was studied as a source of galacturonic acid. For this purpose a commercial enzyme mixture (Pectinex ® 100 l from Novo Nordisk) was used to degrade extracted sugar-beet pulp to galacturonic acid in high yields and at short retention times. Because sugar-beet is a very complex substrate with a varying, non-standardisable composition, the kinetics of this enzyme mixture were studied at first with citrus- and sugar-beet pectin as model substrates, in order to define a starting point for a comparison. The degradation of the citrus- and sugar-beet pectin was carried out in acetate buffer (pH 4) and the decomposition of extracted sugar-beet pulp in water (pH 4.4), with a view to an industrial application. It was found, that for all substrates no substrate inhibition, but a strong product inhibition is given. Therefore, the use of extracted sugar-beet (and other related compounds) can enzymatically yield only low concentrations of galacturonic acid.

Im Kapitel 6 wird die Anwendung der anaeroben Verfahrenstechnik bei der Behandlung von Abwassern aus der Lebensmittel- und Getrankeindustrie vorgestellt. Dazu wird eine Vielzahl von grostechnischen Anwendungen unterschiedlicher Reaktortypen und unterschiedlicher Gesamtkonzepte von insgesamt 24 Autoren aus der Praxis beschrieben. Mit den Angaben zu einzelnen Bemessungsdetails und Erfahrungswerten sind viele Erkenntnisse fur die praktische Nutzung besonders wertvoll. Der Einsatz anaerober Verfahren im industriellen Bereich beschrankte sich zunachst auf Brauereien, Brennereien und weitere Anlagen in der Lebensmittelindustrie (1960 -80er Jahre). Obwohl die Anaerobtechnik grundsatzlich bei allen Industrieabwassern mit organischen Inhaltsstoffen eingesetzt werden kann und mittlerweile auch eingesetzt wird, ist die Anwendung in Deutschland im Lebensmittel- und Getrankebereich immer noch besonders weit verbreitet. Abhangig von der Abwassercharakteristik unterscheiden sich die eingesetzten anaeroben Reaktoren sowie die notwendigen Verfahrensschritte zur Vor- und Nachbehandlung des Abwassers. Dazu werden geeignete Verfahren und praktische Beispiele aus nahezu allen Bereichen der Lebensmittelindustrie (Fruchtsaftindustrie, Erfrischungsgetrankeindustrie, Brauereien, Schlacht- sowie Fleisch- und Fischverarbeitungsbetriebe, Starke-Herstellung, Kartoffelveredelungsindustrie, Pektinfabriken, Zuckerindustrie, Ethanolherstellung , Hefeindustrie, Suswarenindustrie Molkereien) vorgestellt.

In batch-experiments (in lab-scale fluidized bed reactors) the inhibition of acetate- and propionate-degradation by propionate (substrate inhibition) and the inhibition of propionate degradation by acetate (product inhibition) was studied. Various models were compared by fitting them to the experimental data. The importance of independent variation of the acid concentrations and the pH for the experimental design is discussed. The substrate inhibition was best described by a model of inhibition by undissociated acid with an additional independent pH influence. The inhibition by propionic acid was only slight in the practically relevant range of concentrations. However, the propionate degrading bacteria were sensitive against low pH. The product inhibition was best described with the model of competitive inhibition. The inhibition already occurred from an acetate/propionate-ratio of 1 upwards. A complete standstill of the propionate degradation at high acetate/propionate-ratios, as expected because of the proximity to the thermodynamic equilibrium, was not observed.

The acceptor reaction of the dextransucrase from L. mesenteroides NRRL B-512 F is of technical interest for oligosaccharide synthesis. In this work the acceptor reaction of maltose, the strongest acceptor known so far, has been investigated at different experimental conditions. The data obtained were used for modeling of dextransucrase catalysis with a kinetic model that had been developed earlier.

The kinetic behavior of soluble and insoluble forms of dextransucrase from Leuconostoc mesenteroides NRRL B-1299 was investigated with sucrose as substrate and maltose as acceptor. To study the parameters involved, a kinetic model was applied that was previously developed for L. mesenteroides NRRL B-512F dextransucrase. There are significant correlations between the parameters of the soluble form of B-1299 dextransucrase and those calculated for the B-512F enzyme; that is, their properties are comparable and differ from those of the insoluble form of B-1299 dextransucrase. Whereas the calculated parameters for high maltose concentrations describe the kinetic behavior very well, the time curves for low maltose concentrations were not described correctly. Therefore, the parameters were calculated separately for the two ranges. Copyright 1999 John Wiley & Sons, Inc.

Dextransucrase catalyses the formation of dextran, but also of numerous oligosaccharides from sucrose and different acceptors, if appropriate conditions are chosen. Much experimental work has been carried out and a scheme of reactions and a mathematical model have been developed to describe the complex kinetic behaviour of the enzyme. A computer program was used to calculate the parameters of the model from a broad range of experimental data, investigating a large number of kinetic tests with the acceptors maltose and fructose. The results lead to design considerations for a continuous reactor system with immobilized dextransucrase to produce leucrose, a disaccharide of industrial interest.

Samples taken from a fluidized-bed reactor revealed very low saturation constants for the degradation of acetate (2–12 mg/l) and propionate (

The paper deals with a mathematical model for anaerobic treatment of waste water from sugar industry which has been developed for supporting the scale-up of a fluidized bed reactor. The dynamic model is based on material balance equations for substrates and products in gas and liquid phase. The effects taken into account are the biological degradation steps including chemical equilibria and mass transport between gas and liquid phase as well as convection and dispersion. Axial gradients of pH-values are calculated from a charge balance. Simulation results show reasonable agreement with measured gradients of substrates and pH in a 10 m3 fluidized bed reactor. For a new 500 m3 fluidized bed reactor simulations are performed to study the effects of increased hydrostatic pressure and increased ratio of feed to recirculation rate on the pH-values at the bottom of the reactor. The results indicate that for high COD-loading rates stationary pH-gradients may have significant influence upon the outcome of the process.

Disaccharides were microbially transformed to their corresponding 3-keto-derivatives by resting cells of Agrobacterium tumefaciens NCPPB 396. The kinetics and yield of this highly specific oxidation depend on several factors. The oxygen concentration especially has a major influence on the production of 3-keto-derivatives and was investigated kinetically with respect to low stationary oxygen concentrations in solution. Experiments showed unconventional results that conflicted with normal Michaelis-Menten kinetics. A kinetic model was developed and the kinetic constants were calculated. The model and experimental data for sucrose, maltose, iso-maltulose (palatinose), and leucrose are in good agreement with each other. Initial reaction rates with different sugars using constant oxygen concentrations resulted in a Michaelis-Mentent type function. The complete kinetics, including the effect of disaccharide and oxygen concentrations, are presented.

A denitrifying bacterial biofilm population established on a polypropylene substratum of a fixed-film reactor was characterized by microscopy, scanning electron microscopy and immunofluorescence after 120 days of operation. The reactor, operated at pH 7.0, 22°C, and - 180 mV with synthetic wastewater containing methanol/nitrate, achieved a denitrification rate of 0.24 mol NO 3 - l -1 day -1 with a removal efficiency for nitrate of 95%-99% at an organic loading rate of 0.325 mol methanol l -1 day -1 . The gas produced contained 2%-3% (v/v) methane and 3%-4% (v/v) carbon dioxide in addition to nitrogen. The biofilm contained mainly cells of Methanobrevibacter arboriphilus antigenically related to strain DC, short, flagellated, gram-negatively staining rods of Pseudomonas sp. antigenically related to Pseudomonas stutzeri strain AN11, non-identified pink-pigmented rods and small lemon-shaped cells with mono- and bipolar appendages resembling prosthecate Hyphomicrobium sp. The biofilm analysis provided evidence for a syntrophy between the denitrifying, methylotrophic, bacterial consortium and hydrogenotrophic methanogens, which were identified by antigenic fingerprinting with 17 antibody probes.

Leucrose formation from sucrose and fructose by dextransucrase is of practical interest. It has been investigated at different experimental conditions, including the influence of temperature on reaction rate and selectivity. Under appropriate conditions high product yield can be obtained. Furthermore, a model is presented that allows interpretation of the experimental data.

The integration of all relevant tools for bioreaction engineering has been a recent challenge. This approach should notably favor the production of oligo- and polysaccharides, which is highly complex due to the requirements of regio- and stereoselectivity. Oligosaccharides (OS) and polysaccharides (PS) have found many interests in the fields of food, pharmaceuticals, and cosmetics due to different specific properties. Food, sweeteners, and food ingredients represent important sectors where OS are used in major amounts. Increasing attention has been devoted to the sophisticated roles of OS and glycosylated compounds, at cell or membrane surfaces, and their function, e.g., in infection and cancer proliferation. The challenge for synthesis is obvious, and convenient approaches using cheap and readily available substrates and enzymes will be discussed. We report on new routes for the synthesis of oligosaccharides (OS), with emphasis on enzymatic reactions, since they offer unique properties, proceeding highly regio- and stereoselective in water solution, and providing for high yields in general.

The integration of all relevant tools for bioreaction engineering has been a recent challenge. This approach should notably favor the production of oligo- and polysaccharides, which is highly complex due to the requirements of regio- and stereoselectivity. Oligosaccharides (OS) and polysaccharides (PS) have found many interests in the fields of food, pharmaceuticals, and cosmetics due to different specific properties. Food, sweeteners, and food ingredients represent important sectors where OS are used in major amounts. Increasing attention has been devoted to the sophisticated roles of OS and glycosylated compounds, at cell or membrane surfaces, and their function, e.g., in infection and cancer proliferation. The challenge for synthesis is obvious, and convenient approaches using cheap and readily available substrates and enzymes will be discussed. We report on new routes for the synthesis of oligosaccharides (OS), with emphasis on enzymatic reactions, since they offer unique properties, proceeding highly regio- and stereoselective in water solution, and providing for high yields in general.

Preface.List of Contributors.1 Bacterial Metabolism in Wastewater Treatment Systems (Claudia Gallert and Josef Winter).1.1 Introduction.1.2 Decomposition of Organic Carbon Compounds in Natural and Manmade Ecosystems.1.3 Nitrogen Removal During Wastewater Treatment.1.4 Enhanced Biological Phosphate Removal.1.5 Biological Removal, Biotransformation, and Biosorption of Metal Ions from Contaminated Wastewater.1.6 Aerobic and Anaerobic Degradation of Xenobiotics.1.7 Bioaugmentation in Wastewater Treatment Plants for Degradation of Xenobiotics.References.2 Industrial Wastewater Sources and Treatment Strategies (Karl-Heinz Rosenwinkel, Ute Austermann-Haun, and Hartmut Meyer).2.1 Introduction and Targets.2.2 Wastewater Flow Fractions from Industrial Plants.2.3 Kinds and Impacts of Wastewater Components.2.4 General Processes in Industrial Wastewater Treatment Concepts.2.5 Wastewater Composition and Treatment Strategies in the Food Processing Industry.References.3 Activated Sludge Process (Rolf Kayser).3.1 Process description and historical development.3.2 Technological and microbiological aspects.3.3 Plant Configurations.3.4 Design procedure.References.4 Modeling of Aerobic Wastewater Treatment Processes (Mogens Henze).4.1 Introduction.4.2 Purpose of Modeling.4.3 Elements of Activated Sludge Models.4.4 Presentation of Models.4.5 The Activated Sludge Models Nos. 1, 2 and 3 (ASM1, ASM2, ASM3).4.6 Wastewater Characterization.4.7 Model Calibration.4.8 Computer Programs.4.9 Use of Models.References.5 High-rate Anaerobic Wastewater Treatment (Hans-Joachim Jordening and Klaus Buchholz).5.1 Introduction.5.2 Basic Principles.5.3 Reactor Design Parameters.5.4 Reactor Operation.5.5 Conclusions.References.6 Modeling of Biogas Reactors (Herbert Markl).6.1 Introduction.6.2 Measuring Techniques.6.3 Kinetics.6.4 Hydrodynamic and Liquid Mixing Behavior of the Biogas Tower Reactor.6.5 Mass Transport from the Liquid Phase to the Gas Phase.6.6 Influence of Hydrostatic Pressure on Biogas Production.6.7 Outlook.References.7 Aerobic Degradation of Recalcitrant Organic Compounds by Microorganisms (Wolfgang Fritsche and Martin Hofrichter).7.1 Introduction: Characteristics of Aerobic Microorganisms Capable of Degrading Organic Pollutants.7.2 Principles of Bacterial Degradation.7.3 Degradative Capacities of Fungi.7.4 Conclusions.References.8 Principles of Anaerobic Degradation of Organic Compounds (Bernhard Schink).8.1 General Aspects of Anaerobic Degradation Processes.8.2 Key Reactions in Anaerobic Degradation of Certain Organic Compounds.8.3 Concluding Remarks.References.9 Soil Remediation and Disposal (Michael Koning, Karsten Hupe, and Rainer Stegmann).9.1 Introduction.9.2 Thermal Processes.9.3 Chemical/Physical Processes.9.4 Biological Processes.9.5 Disposal.9.6 Utilization of Decontaminated Soil.9.7 Conclusions.References.10 Bioremediation by the Heap Technique (Volker Schulz-Berendt).10.1 Introduction.10.2 Principles of the Heap Technique.10.3 Different Heap Techniques.10.4 Efficiency and Economy.References.11 Bioreactors (Rene H. Kleijntjens and Karel Ch. A. M. Luyben).11.1 Introduction.11.2 Bioreactors.11.3 Slurry Bioreactors.11.4 Solid-State Bioreactors.11.5 Comparison of Bioreactors.11.6 Conclusions and Outlook.References.12 In-situ Remediation (T. Held and H. Dorr).12.1 Introduction.12.2 Investigations.12.3 Remediation Technologies.12.4 Monitoring.12.5 Outlook.References.13 Composting of Organic Waste (Frank Schuchardt).13.1 Introduction.13.2 Waste Materials for Composting.13.3 Fundamentals of Composting Process.13.4 Composting Technologies.13.5 Composting Systems.13.6 Compost Quality.References.14 Anaerobic Fermentation of Wet and Semidry Garbage Waste Fractions (Norbert Rilling).14.1 Introduction.14.2 Basic Aspects of Biological Waste Treatment.14.3 Processes of Anaerobic Waste Treatment.14.4 Conclusions.References.15 Landfill Systems, Sanitary Landfilling of Solid Wastes, and Long-term Problems with Leachate (Kai-Uwe Heyer and Rainer Stegmann).15.1 Introduction.15.2 Biochemical Processes in Sanitary Landfills.15.3 Sanitary Landfilling and Leachate Control Strategies.15.4 Long-term Problems with Leachate.15.5 Controlled Reduction of Leachate Emissions.References.16 Sanitary Landfills: Long-term Stability and Environmental Implications (Michael S. Switzenbaum).16.1 Introduction.16.2 Integrated Waste Management.16.3 Land Disposal.16.4 Leachate and Gas Management.16.5 Summary and Conclusions.References.17 Process Engineering of Biological Waste Gas Purification (Muthumbi Waweru, Veerle Herrygers, Herman Van Langenhove, and Willy Verstraete).17.1 Introduction.17.2 Biological Waste Gas Purification Technology.17.3 Performance Parameters.17.4 Characteristics of the Waste Gas Stream.17.5 Process Principles.17.6 Reactor Performance.17.7 Reactor Control.17.8 Perspectives.Acknowledgments.References.18 Commercial Applications of Biological Waste Gas Purification (Derek E. Chitwood and Joseph S. Devinny).18.1 Background.18.2 Applications.References.19 Perspectives of Wastewater, Waste, Off-gas and Soil Treatment (Claudia Gallert and Josef Winter).19.1 Introduction.19.2 Wastewater Handling.19.3 Solid Waste Handling.19.4 Off-gas Purification.19.5 Soil Remediation.19.6 Drinking Water Preparation.19.7 Future Strategies to Reduce Pollution and Conserve a Natural, Healthy Environment.Subject Index.

The exo-fructosyltransferase produced from B. subtilis NCIMB 11871 strain transfers the fructose moiety from donor α12 linked saccharides such as sucrose, raffinose and stachyose to the acceptor d -galactose, leading to the sucrose analogue, galactosyl-fructoside. Here, we report detailed kinetic studies. The enzyme showed a remarkably high optimal temperature at 50 °C and was effectively immobilised on Eupergit® C 250 L and Trisopor®-Amino. This is also the first report about the equilibrium of the transfructosylation reaction, its activation energy determination, the structure of the product and its preparative scale isolation.

The acceptor reactions of dextransucrase offer the potential for a targeted synthesis of a wide range of di-, tri- and higher oligosaccharides by the transfer of a glucosyl group from sucrose to the acceptor. We here report on results which show that the synthetic potential of this enzyme is not restricted to ‘normal’ saccharides. Additionally functionalized saccharides, such as alditols, aldosuloses, sugar acids, alkyl saccharides, and glycals, and rather unconventional saccharides, such as fructose dianhydride, may also act as acceptors. Some of these acceptors even turned out to be relatively efficient: α- d -glucopyranosyl-(1→5)- d -arabinonic acid, α- d -glucopyranosyl-(1→4)- d -glucitol, α- d -glucopyranosyl-(1→6)- d -glucitol, α- d -glucopyranosyl-(1→6)- d -mannitol, α- d -fructofuranosyl-β- d -fructofuranosyl-(1,2′:2,3′)-dianhydride, 1,5-anhydro-2-deoxy- d - arabino -hex-1-enitol (‘ d -glucal’), and may therefore be of interest for future applications of the dextransucrase acceptor reaction.

Zuckerruben stellen zusammen mit Zuckerrohr die Rohstoffquelle fur die Produktion von Zucker (Saccharose) dar. Die Zuckerrube enthalt etwa 22 bis 25% Trockensubstanz, davon: 14 -18% Saccharose, 1-1,2% Pektinstoffe, 0,1% Rohfett, 1,1-1,3% Rohfaser, 2,2-3,0% stickstofffreie Extraktstoffe (auser Saccharose) sowie 0,7-0,9% anorganische Bestandteile [1]

Charakterisierung und geometrische Optimierung der strukturierten Stoffaustauschpackung QVF DURAPACK Prof. Dr. H.-J. Bart (E-Mail: bart@mv.uni-kl.de), C. Dreiser, Dr.-Ing. G. Gneist TU Kaiserslautern, Lehrstuhl fur Thermische Verfahrenstechnik, Gottlieb-Daimler-Strase 44, D-67653 Kaiserslautern, Germany De Dietrich Process Systems GmbH, Hattenbergstrase 36, D-55122 Mainz, Germany DOI: 10.1002/cite.201250225