Immobilisation of glycosidases from commercial preparation on magnetic beads: Part 2: Aroma enhancement in wine using immobilised glycosidases

Most of the terpenes in wines are conjugated to various sugars, representing a significant reservoir of aromatic precursors. To promote the release of these terpenes, certain enzymes, such as β-glucosidase, α-arabinosidase and α-rhamnosidase, are necessary. A simple and cost-effective procedure for the immobilisation of multiple glycosidase activities (β-D-glucopyranosidase, α-L-arabinofuranosidase, α-L-rhamnopyranosidase and β-D-xylopyranosidase) from commercial Aspergillus niger preparation onto magnetic beads as carriers was developed as reported in Part 1 (Ferner et al. 2016).The aim of this work was to analyse a possible application of this immobilised biocatalyst due to its well-known advantages over soluble enzyme preparations – that is, control of the reaction process and preparation of enzyme-free products. Volatile compounds were analysed by gas chromatography (mass spectrometric detection). After the treatment of the model wine with different glycosides and white wine with immobilised glycosidases, the amount of free terpenes was significantly increased with respect to that of the control wine.The results of this study are of considerable interest for possible future applications of immobilised enzymes in the wine-making industry

Study on Optimizing High-Gradient Magnetic Separation-Part 2: Experimental Evaluation of the Performance of a New Designed Magnetic Filter

Abstract The introduction of functionalized magnetizable particles and high-gradient magnetic separation represents a time and money saving alternative to conventional purification and separation unit operations in the biotechnical sector. This technique has some advantages especially for the recycling of immobilized enzymes. A new magnetic filter with sight glasses was constructed and produced to study the performance of high-gradient magnetic separation at varied parameters. By optical analysis the buildup of a clogging was identified as the major parameter which affected the separation performance. For the cleaning procedure, a two-phase flow of water with highly dispersed air bubbles was tested which led to a nearly complete cleaning of the filter chamber

Application of Magnetic Filters in Bioprocess Engineering Part 3-New Measuring Method for Quantification of Magnetic Beads in Flowing Suspensions

High-gradient magnetic separation (HGMS) allows solid/solid/liquid separation in one step and can therefore be used as first capture step in downstream processing of biotechnology products. Magnetic beads are retained in the filter compartment while biomass, solvent and dissolved substances should pass the magnetic filter unhindered. During magnetic filtration agglomeration areas of magnetic beads continuously build up and it is possible that the biomass drags with it some magnetic beads and hence a part of the sorbed product as well. For proper in-process operation of a HGMS filter, it is necessary to measure the concentration of the magnetic beads in the suspension at the outlet of the filter. A novel measurement technique using a flow-through magnetic sensor was developed which allows quantifying the magnetic beads in flowing suspensions

Chemische und verfahrenstechnische Untersuchungen zur Erzeugung ferrithaltiger Suspensionen im Hinblick auf einen Einsatz als Zusatzstoff fuer Magnetseparation

The purpose of this research is to develop a process for the continuous removal of heavy metals from waste water using magnetic separators. Investigations concerning the formation of magnetite (Fe_3O_4) and heavy-metal ferrites (MFe_2O_4) were carried out. By the addition of these mostly ferri- or ferromagnetic substances, the magnetic properties of mixed precipitation products can be improved such that satisfactory separation efficiencies can be achieved even at moderate flux densities. When selecting the reaction temperature, ion concentrations and oxidation conditions, particular attention was paid to them being practicable in waste water treatment. The reaction variants which were applied included (1) the oxidation of an iron(II)-hydroxide suspension with air ('oxidation method') and (2) the hydroxide precipitation of iron(II) and iron(III) salt solutions ('mixing method'). The solids generated were characterised using various solid-state analytical methods and investigated with regard to their magnetic properties. Depending on the reaction conditions chosen, the precipitates were varying mixtures of the following solids: magnetite, maghemite, geothite, #delta#-FeOOH and amorphous iron(III)-oxide hydrates mostly containing sulphate. With up to about 1 mg L"-"1 min"-"1 oxygen being supplied to the reactor ('oxidation method'), magnetite was seen to be formed sufficiently at temperatures equal to and above 15 C. Using the 'mixing method' this was already achieved at a temperature of 5 C. Increasing concentrations of heavy-metal ions (e.g. Cu"2"+, Cd"2"+, Zn"2"+) or certain anions (e.g. of phosphoric or carbonic acid) lead to a reduction in the ferrite proportion of the reaction products. The saturation magnetisations of the precipitates achieved under suitable reaction conditions (60-80 A m"2 kg"-"1) are totally sufficient for the panned use. The results were confirmed in a technical-scale facility with a continuously operating packed bubble column for the generation of the magnetite suspension and a magnetic separator operated continuously in accordance with the magnetic barrier principle. This facility, operating at a filtration velocit of 3 m h"-"1, achieved 96% copper removal from waste water which had a feed concentration of c(Cu"2"+(=100 mg L"-"1)). (orig.)Available from TIB Hannover: ZA 5141(6174) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman