EP1727823A1 - Method for enriching trehalose with the aid of alumosilicates - Google Patents

Abstract

The invention relates to a method for enriching trehalose from solutions, wherein the enrichment is performed with the aid of an adsorbent. The invention is characterized in that the adsorbent is an alumosilicate. The alumosilicate is preferably a zeolite. The invention also relates to the enrichment and purification of trehalose from fermentation broths, more particularly as coupled product from the fermentative production of other value products.

Description

 Process for the enrichment of trehalose with the help of aluminosilicate

The following invention relates to a method for enriching trehalose from solutions, in which the trehalose is enriched with the aid of an adsorbent.

The disaccharide trehalose (-D-glucopyranosyl-α-D-glucopyranoside) consists of two glucose molecules that are covalently linked to each other via the α, α-1,1 bond. Due to their interesting properties in terms of application technology, trephos is of increasing importance for industry. An important area of application is the stabilization of proteins and peptides, for example of enzymes and vaccines. Trehalose is preferred in the food industry. Trehalose is also used as a substitute for sucrose due to its reduced sweetness and its taste-preserving properties. In addition, trehalose has a stabilizing effect during freezing and drying processes. Another area of application is in the cosmetics sector.

Trehalose is preferably produced enzymatically or by fermentation using suitable microorganisms (Schiraldi, C, et al. (2002). Trehalose Production: Exploiting Novel Approaches. Trends in Biotechnology, vol. 20 (10), pages 420-425 ). Trehalose often also forms as a by-product of fermentations that serve to produce other substances (Hüll, SR, Gray, JSS, et al. (1995). Trehalose as a Common üidustrial Fermentation Byproduct. Carbohydrate Research, vol. 266, pages 147-152 ). In contrast to chemical syntheses, fermentations in particular result in heavily contaminated solutions which can contain cells, proteins, lipids or other sugars, for example.

The trehalose must therefore be enriched from such heavily contaminated solutions and, depending on the intended use, further purified.

Various enrichment and purification methods for trehalose are known in the prior art.

No. 5,759,610 describes a process for the purification of trehalose from cultures of microorganisms, comprising the steps of filtration and centrifugation, treatment with activated carbon, deionization, cleaning with ion exchangers, concentration to syrup-like products, further purification by column chromatography, such as ion exchange column chromatography, activated carbon chromatography and silica gel columns chromatography, as well as precipitation with organic solvents such as alcohol and acetone and filtration through suitable membranes, and fermentation by yeast or alkaline treatment in order to remove or degrade any remaining saccharides. For further cleaning, cooling crystallization or spray drying, for example, are proposed. Trehalose is not adsorbed on an adsorbent.

JP 07000190 (Tadashi, W., et al.) Describes the isolation of trehalose from solid residues from brewery fermentations. The residue is extracted with alcohol and / or treated with ultrasound in order to extract the trehalose from the residue. Furthermore, the enzyme trehalase present in the residue is inactivated by heat treatment. Cleaning is carried out using ion exchange columns and an activated carbon column, among other things. The trehalose is not adsorbed on the columns.

No. 5,441,644 describes a method in which trehalose is purified from a fermentation broth. The process involves, among other things, ultrafiltration and decolorization using activated carbon. The trehalose is not adsorbed on the activated carbon.

A disadvantage of the methods mentioned seems to be that the respective adsorbents are only used for the adsorption of the undesired foreign substances, but do not adsorb the trehalose itself. Since the extraction and cleaning steps have to be adapted to the different foreign substances, they are complicated and difficult to use on an industrial scale. This applies in particular to cleaning from fermentation broths in which the content of trehalose is usually less than 15% of the dry weight (Schiraldi et al. (2002), Trehalose Production: Exploiting Novel Approaches. Trends in Biotechnology, vol. 20 (10 ), Page 421).

According to another method, trehalose as a by-product of fermentation was purified by sequential chromatography over activated carbon and Bio-Gel P-2 (Hüll, SR, Gray, JSS, et al. (1995). Trehalose as a Common Industrial Fermentation Byproduct. Carbohydrate Research, vol. 266, pages 147-152). However, the method is only a detection method, but not a method that is suitable for use on an industrial scale.

In addition to the method described above, US Pat. No. 5,441,644 mentions a further method from the prior art, in which a trehalose-containing acetonitrile solution of a silica Gel chromatography is subjected. The document mentions that these chromatographic processes are not suitable for trehalose enrichment or purification on an industrial scale.

Buttersack et al. (Specific Adsorption from Aqueous Phase on Apolar Zeolites, Progress in Zeolite and Microporous Materials, vol. 105, p. 1723-1730, 1997) describe the binding of certain mono- and disaccharides to selected FAU, PEA, and MH zeolites. Very different adsorption properties were found for individual disaccharides. Trehalose has not been studied.

In another work, Buttersack et al. the binding of disaccharides to different Y-zeolites and dealuminated Y-zeolites (Buttersack et al. (1994). Adsorption of Glucose and Fructose containing Disaccharides on Different Faujasites. Studies in Surface Science and Catalysis, vol. 84, p. 1363-1371 ). They emphasized the importance of the fructose residue in the disaccharides investigated for adsorption on the zeolites. Trehalose has not been studied and has no fructose residue.

A disadvantage of the previous adsorbents is that they have very general adsorption properties and cannot be tailored to the respective process.

There is therefore a need for processes for enriching trehalose from solutions using better adsorbents, in particular for adsorbents which can be tailored to the particular process. The object of the present invention is therefore to provide such a method, in particular for use in chromatographic methods. Furthermore, it is an object of the present invention to provide a method which enables trehalose from fermentation broths, in particular from fermentation broths from lysine production, to be enriched.

The solution to the problem is based on the known method for enriching trehalose from solutions with the aid of an adsorbent. The process according to the invention is then characterized in that the adsorbent is an aluminosilicate.

Compared to the adsorbents used according to the prior art (eg activated carbons and ion exchangers), aluminosilicates, in particular zeolites, offer the advantage that a larger number of variants can be produced and the adsorbent can thus be better tailored to the separation problem. Trehalose can be made by a variety of known methods. Traditionally, trehalose is produced by fermentative processes, with enzymatic production processes now being established (Schiraldi, C, et al. (2002) Trehalose Production: Exploiting Novel Approaches. Trend in Biotechnology, vol. 20 (10), p. 420- 425). Three main enzymatic routes for trehalose synthesis were discovered in microorganisms: (1) a phosphorylase system in fungi and yeast, (2) a glucosyltransferase hydrolase system in mesophilic and extremophilic bacteria, and (3) a trehalose synthase-catalyzed Transglycosylation from maltose to trehalose (e.g. JP 09098779, KR99029104).

The term enrichment is known to the person skilled in the art. According to the present invention, the term enrichment relates in particular to increasing the proportion of trehalose in relation to undesirable foreign substances. This typically corresponds to the proportion of trehalose in the dry weight of the product.

In the preferred embodiment, the term enrichment also includes the purification of trehalose. The term cleaning is known to the person skilled in the art. In the present context, the aim of purification is in particular to achieve a purity of trehalose in which trehalose is essentially free of other substances. In particular, it means trehalose in crystalline form.

An enrichment or purification process only makes economic sense if the yield is satisfactory. It is therefore a further aim of the present process to achieve both a high concentration and a high yield.

With regard to the solution, there are no particular restrictions with regard to the solvents, for example water or acetonitrile. The solution is preferably an aqueous solution.

An adsorbent in the sense of the present invention is a solid or gel-like substance, on the surface of which the adsorption of another substance takes place. The term surface also refers to the inner surface of a three-dimensional matrix, for example the inner surfaces of the three-dimensional framework of a zeolite.

Examples of adsorbents in the context of the present invention are silica gel (silica gel), activated carbon and aluminosilicates. Alumosilicates (aluminosilicates) are known to the person skilled in the art. The term aluminosilicates includes, for example, acid-activated bentonites (bleaching earths) and zeolites.

Acid-activated bentonites (bleaching earths) are bentonites whose smectites (swellable clay minerals) have been partially dissolved by acid treatment and which therefore have a high surface area and a large micropore volume. Bentonites are clays that have arisen from the weathering of volcanic ash (tufa) and consist of the minerals montmorillonite and beidelleit (mineral group of the smectites).

Zeolites are particularly preferred aluminosilicates in the context of the present invention. In this context, zeolites which do not contain aluminum can also be covered by the invention.

Zeolites are a widespread group of crystalline silicates, specifically of water-containing alkali or alkaline earth aluminosilicates of the general formula M ₂ / _z O • Al O ₃ • x SiO ₂ • y H ₂ O, where M = 1- or polyvalent metal (usually an alkali or alkaline earth cardion) H or NH ₄ U. a., z = valence of the cation, x = 1.8 to about 12 and y = 0 to about 8. The stoichiometric ratio of SiO ₂ to Al ₂ O ₃ (module) is an important parameter of the zeolites.

The crystal lattices of the zeolites are made up of SiO ₄ and AlO ₄ tetrahedra, which are linked via oxygen bridges. This creates a spatial arrangement of identically constructed (adsorption) cavities that are accessible via pore openings or channels that are of equal size to one another. Such crystal lattices are able to act as a sieve, which receives molecules with a smaller cross section than the pore openings in the cavities of the lattice, while larger molecules cannot penetrate. Zeolites are therefore also referred to as molecular sieves. Electrostatic interactions, hydrogen bonds and other intermolecular forces also play a role in adsorption. Many chemical and physical properties of the zeolites depend on the Al content.

The term zeolites according to the present invention refers to both natural and synthetic zeolites.

The naturally occurring zeolites are the result of hydrothermal conversion from volcanic glasses or tuff-containing deposits. The natural zeolites can be divided into fiber zeolites (for example mordenite, MOR), leaf zeolites, and the so-called cube zeolites (e.g. faujasite, FAU, and offretite, OFF). The different zeolites are usually assigned three-letter codes (eg MOR, FAU, OFF).

The synthetic zeolites are made from SiO ₂ -containing (e.g. water glasses, silica fillers, silica sols) and Al ₂ O ₃ -containing (e.g. aluminum hydroxides, aluminates, kaolins) substances which together with alkali hydroxides (mostly NaOH ) at temperatures above 50 ° in the aqueous phase to form the crystalline zeolites.

For industrial use as an adsorbent, synthetic zeolites can be subjected to further modifications.

The zeolite should preferably have a pore size of at least 7 Å. Pore size and polarity of the zeolite have an influence on the distribution weight e.g. different sugars, e.g. the separation property results in a chromatographic use. Low-aluminum zeolites are generally more polar and therefore primarily suitable for the adsorption of sugars.

As already described, zeolites can be tailored to a separation problem. The pore size can be influenced by the primary production, the polarity can then be varied by post-treatment by reducing the aluminum content.

Preferred zeolites according to the present invention are FAU, BEA and OFF. Advantageous properties of different zeolites in the context of the present invention can be seen from Example 1. OFF is particularly preferred.

The enrichment with the aid of the aluminosilicate can basically be done in two different ways. The aluminosilicate can either adsorb the undesired foreign substances so that the trehalose remains in the solution, or it can adsorb the trehalose so that the undesired foreign substances remain in the solution. In both cases it is preferred if the adsorption takes place as selectively as possible.

Fixed bed, moving bed and fluidized bed adsorbers can be used as adsorbers. The adsorption can be carried out batchwise or continuously. In the embodiment in which the trehalose is adsorbed on the aluminosilicate there are a number of advantages. The number of processing steps required to isolate trehalose is reduced by selective enrichment of the trehalose (in contrast to previous methods for isolating trehalose, in which the often very different undesirable foreign substances are separated step by step). The number of by-product / waste streams is reduced compared to the step-by-step removal of unwanted foreign substances. Due to selective adsorption, the trehalose is already in high purity after a primary enrichment step with the aluminosilicate. The manufacturing costs are reduced due to the reduced number of processing steps and the reduced number of by-product / waste streams. Furthermore, comparatively low-concentration trehalose can be enriched inexpensively by selective enrichment.

In this embodiment, preferred alumosilicates are therefore alumosilicates, in particular zeolites, to which trehalose is adsorbed, preferably with high selectivity towards undesirable foreign substances present in the solution.

After adsorption of the trehalose on the aluminosilicate, the trehalose can be eluted from the aluminosilicate as a further step. Elution takes place, for example, by elution with methanol, ethanol, water, hot water (50-100 ° C), hot methanol (50-65 ° C), hot ethanol (50-80 ° C), or other suitable eluents, for example methylene chloride , Acetonitrile, NMP (N-methyl-2-pyrrolidone), DMSO (dimethyl sulfoxide), low-chain ketones or low-chain ethers. In this context, low-chain means a chain length of up to C10, preferably up to C6, particularly preferably up to C4.

Another embodiment of the invention relates to a method for the enrichment of trehalose, in which the adsorbent is used in the context of a chromatographic separation. In chromatographic methods, the trehalose can be separated from other substances present in the solution by means of the different transit time behavior. This creates fractions with eluates containing the trehalose.

For the purposes of the present invention, the term “chromatography” encompasses all known and suitable chromatographic separation processes, for example fixed bed chromatography, moving bed chromatography and simulated moving bed chromatography. The chromatography can be carried out batchwise or continuously. Continuous chromatography can, for example, be nuous Rotating Annular Chromatograph (CRAC), a True Moving Bed Chromatograph (TMBC) or in a Simulated Moving Bed Chromatograph (SMB).

A further enrichment or purification can be carried out from the eluate containing the trehalose by means of further suitable processes known to the person skilled in the art.

For example, trehalose can be further enriched or purified by precipitation. Either desired recyclables or unwanted foreign substances can be precipitated. The precipitation can be initiated, inter alia, by adding a further solvent, adding salts or varying the temperature. The resulting precipitate of solids can be separated off by methods known to the person skilled in the art.

For example, solids can be separated by filtration, such as pressure and vacuum filtration. Cake, depth and cross-flow filtrations are possible, for example. Cross-flow filtration is preferred. Microfiltration for separating solids> 0.1 μm is particularly preferred.

Another possibility for separating solids is sedimentation and / or centrifugation. Various types of designs can be used for centrifugation, for example tube and basket centrifuges, in particular push-type, inverting filter centrifuges and plate separators.

As a further enrichment or purification step, treatment with activated carbon or with ion exchangers (anion exchangers and / or cation exchangers) can be carried out. Such process steps are known from the prior art (see, for example, US 5,441,644, US 5,858,735, and EP 0555 540 AI).

Additional possibilities for enrichment, in particular for cleaning, are the use of micro and ultrafiltration (for example as cake, deep and cross-flow filtrations) and in reverse osmosis. Among other things, microporous, homogeneous, asymmetrical and electrically charged membranes are used, which are produced by known methods. Typical materials for diaphragms are cellulose esters, nylon, polyvinyl chloride, acrylonitrile, polypropylene, polycarbonate and ceramics.

The membranes can be used, for example, as a plate module, spiral module, tube bundle and hollow fiber module. In addition, the use of liquid membranes is possible. borrowed. The trehalose can both be enriched on the feed side and discharged via the retentate stream and also depleted on the feed side and discharged via the filtrate / permeate stream.

Various methods known to the person skilled in the art can be used for the further enrichment of trehalose, in particular the cleaning and packaging.

A preferred method is crystallization. Crystallization can be achieved for example by cooling, evaporation, vacuum crystallization (adiabatic cooling), reaction crystallization and salting out. Crystallization can e.g. in stirred and unstirred kettles, in the direct contact process, in evaporation crystallizers, in vacuum crystallizers batchwise or continuously e.g. in forced-circulation crystallizers (Swenson forced-circulation crystallizers) or fluidized-bed crystallizers (Oslo-type). Fractional crystallization is also possible.

The crystallization of trehalose is fundamentally familiar to the person skilled in the art and has been described in detail, including crystallization from aqueous solutions (see also columns 4 and 5 in US Pat. No. 5,441,644). For example, crystallization can be facilitated by prior ultrafiltration.

A particularly typical method for the crystallization of trehalose is the cooling crystallization from suitable solvents, for example ethanol, methanol, water, methylene chloride, acetonitrile, NMP, DMSO, low-chain ketones or low-chain ethers. In this context, low-chain means a chain length of up to C10, preferably up to C6, particularly preferably up to C4.

Another crystallization method is precipitation crystallization. The trehalose is present, for example, in water and is then precipitated by adding a solvent of lower solubility, for example a low-chain alcohol or a low-chain ketone. In this context, low-chain means a chain length of up to C10, preferably up to C6, particularly preferably up to C4.

Crystallization can be accelerated by adding small amounts of trehalose crystals, the trehalose crystals serving as nuclei.

Drying is another method for further enrichment of trehalose, in particular for cleaning and packaging. There are processes for convection drying such as drying ovens, tunnel dryers, belt dryers, disc dryers, jet dryers, Fluid bed dryer, ventilated and rotating drum dryer, and spray drying. A preferred method in the context of the present invention is spray drying. Other processes use contact drying, such as paddle dryers. Heat radiation (infrared) and dielectric energy (microwaves) can also be used for drying. Another area is vacuum or freeze drying. Evaporation is also possible, ie drying that leads to an enrichment but not necessarily to dryness.

Another method for the further enrichment of trehalose, in particular for cleaning and packaging, is nanofiltration. All or part of the trehalose is retained on the retentate side and thus enriched.

It is obvious to the person skilled in the art that the further enrichment steps mentioned can take place both before and after the treatment with the aluminosilicate according to the invention.

In a further embodiment, the present invention relates to a process for the enrichment of trehalose from solutions which originate from the enzymatic synthesis of trehalose. Enzymatic trehalose synthesis is known to the person skilled in the art (see, for example, Schiraldi et al. (2002), Trehalose Production: Exploiting Novel Approaches. Trends in Biotechnology, vol. 20 (10), pages 421-425, and also US Pat. No. 5,919,668 and EP 0990704 A2).

In a further embodiment, the solutions are fermentation broths.

Fermentation broths in the sense of the present invention arise in the culture of eukaryotic and prokaryotic cells, in particular of microorganisms (for example bacteria, yeasts or other fungi).

Preferred microorganisms in the synthesis of trehalose are Saccharomyces spec, in particular Saccharomyces cerevisiae; Bacillus spec; Candida spec, especially Candida fermentii; Escherichia coli; Corynebacterium spec, in particular Corynebacterium glutamicum, Corynebacterium acetoacidofirum (eg ATCC 13870), Corynebacterium lilium (eg ATCC 15990) and Corynebacterium melaseccola (eg ATCC 17965); Pseudomonas spec; Nocardia spec; Brevibacterium spec, in particular Brevibacterium lactofermentum (eg ATCC 13869), Brevibacterium flavum (eg ATCC 14067), and Brevibacterium divaricatium (eg ATCC 21642); Arthrobacter spec, in particular Arthrobacter sulfureis (e.g. ATCC 15170), Arthrobacter citoreus (e.g. ATCC 11624); Aspergillus spec; Streptomyces spec; Microbacterium spec, in particular Mikrobacterium ammoniaphylum (eg ATCC 15354); Pichia spec; Filobasidium spec, in particular Filobasidium floriforme.

Other suitable microorganisms are known to the person skilled in the art, see for example Miyazaki, J.-L, et al. (1996)., Trehalose accumulation by a basidiomycotinous yeast, Filobasidium floriforme. Journal of Fermentation and Bioengineering, vol. 81 (4), pages 315-319.

Variants of these strains which are derived by mutation or genetic engineering modification or which have an increased ability to synthesize trehalose can also be used in the context of the present invention.

The culture of the microorganisms can also be carried out with the addition of suitable antibiotics, for example to induce the trehalose synthesis by adding a β-lactam ring antibiotic.

The fermentation broth initially contains both the cells and the culture medium. Depending on the type of fermentation, a significant part of the trehalose can accumulate intracellularly. In this case, it makes sense to disrupt the cells used and extract the trehalose using suitable methods. Suitable processes, for example ultrasound treatment, treatment with detergents, alkaline lysis, and / or extraction with alcohol or trichloroacetic acid are known to the person skilled in the art (JP 07 000 190, US 5,441,644)

The fermentation broths generally contain considerable amounts of solids, which should preferably be removed first.

In the present context, the term solids also includes cells and cellular components such as nucleic acids and proteins. To separate solids, in particular from cellular components, it is advantageous to agglomerate them first. This can be done with any suitable method, however, a breakdown of the trehalose (for example by hydrolysis) should be largely avoided. Suitable methods include, for example, alkali treatment, for example Ca (OH) treatment, or heating. Advantageously, any enzymes present with trehalase activity are also inactivated. The solids can then be separated off using suitable processes known to the person skilled in the art. Examples of such processes have already been mentioned above.

The present method is also suitable for enriching trehalose from solutions, in particular fermentation broths, in which trehalose is present in low concentrations, in particular less than 15 percent by weight, measured on the dry weight of the fermentation broth.

The concentration of trehalose is typically between 3 and 8% by weight, measured on the dry weight of the fermentation broth. After separation of another valuable product, for example lysine, the mass fraction of the trehalose can increase to 10-20% by weight, measured on the dry weight of the remaining fermentation broth. If one assumes separation of the biomass as insoluble constituents, then the concentration of the trehalose is 20-40% by weight measured on the dry weight of the fermentation broth.

A further embodiment of the invention therefore also relates to a method for the enrichment of trehalose from fermentation broths in which trehalose is present in a concentration of less than 15 percent by weight, measured on the dry weight of the fermentation broth.

Many fermentations produce several valuable products. Trehalose is also often created as another valuable product. One problem, however, is that the enrichment or purification process for substances produced by fermentation is specially adapted to the respective valuable product (such as cleaning using ion exchange chromatography for amino acids or organic acids). After the enrichment of the first valuable product, other valuable products such as trehalose are included an environment that complicates the enrichment of other valuable products. An example is high ion concentrations after elution of amino acids from ion exchange matrices). This is particularly problematic in the case of trehalose, since trehalose has no special chemical properties (such as low solubility in aqueous solutions or electrical charge) that are suitable for simple enrichment. Therefore, the trehalose is often disposed of with the waste stream from the fermentation.

It is therefore a further object of the present invention to process trehalose as a further valuable product from fermentation broths, from which a first valuable product was or is worked up before or after. In a further embodiment, the present invention therefore relates to a process for the enrichment of trehalose as a further valuable product from fermentation broths from which at least one first valuable product has been or is obtained, comprising the steps of separating solids and enriching the trehalose with the aid of an adsorbent, characterized in that the adsorbent is an aluminosilicate.

The present method is characterized in that it is particularly tolerant of the properties of the solution in which the trehalose is present. The method according to the invention can therefore also be used if the trehalose is present in an environment which would normally make enrichment more difficult.

Conversely, the solution in which the trehalose is present is treated particularly gently with the present method, so that a further valuable product can also be obtained after the enrichment of the trehalose.

The trehalose can therefore be obtained before, after or simultaneously with the first valuable product.

Products of value within the meaning of the present invention include, for example, organic acids, proteinogenic and non-proteinogenic amino acids, nucleotides and nucleosides, lipids and fatty acids, diols, carbohydrates, aromatic compounds, vitamins and co-factors, storage materials such as, for example, PHA (polyhydroxyalkanoates) or PHB (poly hydroxybutyrate), as well as proteins and peptides (e.g. enzymes).

A preferred first product of value according to the present invention is the amino acid lysine.

The present invention further relates to that of aluminosilicates, in particular zeolites, in one of the processes mentioned in this description or the exemplary embodiments.

In the exemplary embodiments, further processes are shown which are suitable for purifying trehalose from fermentation broths from which another valuable product has previously been obtained.

The drawings and examples serve to illustrate the invention in more detail. The attached drawings show in

Fig. 1 shows the selectivity (s) of zeolites for sucrose (sac) and maltose (malt) relative to trehalose (tre).

Fig. 2 shows the selectivity (s) for sucrose (sac) and maltose (malt) relative to trehalose, in relation to the pore size (p) of selected zeolites

Determination of the pore size: Space-filling atom-centered spheres are used to represent the van der Waals volumes for the atoms, the radii of the spheres corresponding to the van der Waals radii as defined in the MSI Program Materials Studio. A magnification factor of 0.9 is applied to the van der Waals radii of the atoms in the zeolite pore and a helium atom is then placed in the center of the pore. The enlargement factor for the Helium van der Waals radius is optimized by hand until the enlarged space-filling volume of the helium atom comes into contact with the space-filling volumes of the zeolite pore. This helium enlargement factor is used as the enlargement factor of the pore (pore size).

Fig. 3 shows the selectivity (s) for hydrocarbons in relation to the pore size (p) of selected zeolites

example 1

To compare the diffusion of sugars in different zeolites quantitatively, theoretical calculations are carried out. Conventional molecular dynamic simulations are carried out along a diffusion coordinate. The diffusion coordinate is determined by a small driving force that is applied along the axis of the farthest pore or the farthest channel. This simulates the effect of a concentration gradient.

First, it is examined whether the simulation delivers qualitatively correct results. For this purpose, the calculated diffusion times for maltose and sucrose in FAU and BEA are compared with experimental measurements. According to the calculations, maltose diffuses significantly more slowly than trehalose and sucrose through FAU (see Table 1). This is in Agreement with experimental data showing that maltose has a significantly lower adsorption capacity than sucrose.

For BEA it is calculated that sucrose does not migrate through the zeolite at all within the time scale used (see Table 2). This effect (no adsorption) is a general characteristic of other 1-2 Fru-disaccharides that would be measured experimentally. From these results for BEA and FAU it is concluded that the calculation provides qualitatively correct predictions for the relative "solubility" of maltose and sucrose in FAU and BEA.

First, a list of candidates for suitable zeolites for the separation of trehalose, maltose and sucrose is made (Table 1).

Molecular dynamics simulations are then carried out with these zeolites for all 3 sugars. In this way, the relative selectivity of the sugars with regard to diffusion through the corresponding channels can be calculated.

The molel-dynamic force field simulations are carried out in a microcanonical ensemble at 298 K. The relative times are measured for molecules that are driven by an electrostatic force through a pore in the zeolite structure. The force is generated by fixing the coordinates of a charged hay atom on the opposite side of the pore of the molecule, the molecule then being evenly charged with a corresponding counter charge on each atom. For example, the 5 atoms of trehalose that are closest to the helium are each assigned a charge of -0.3 q, while the helium atom has a charge of +1.5 q. The remaining atoms in the system are uncharged. The selectivity in Figure 1 is calculated according to the following formula:

Selectivity = ^{? 7> eftαtoe} , where t _sugar = 8000 ps, if t _sugar > 8000 ps ^ Zacker

The calculated diffusion times for the sugars are listed in Table 2.

Table 2:

A graphical representation of the selectivity is shown in FIG. 1. It is clear from FIG. 1 that the individual zeolites have different abilities to separate trehalose from a mixture of sugars. The most versatile seems to be OFF (Offretit), which contains no aluminum and clearly prefers trehalose over the other two sugars. FAU and BEA also show a high relative selectivity for trehalose, but also show a certain selectivity for sucrose and maltose.

Example 2

Enrichment of trehalose by precipitation with calcium hydroxide, centrifugation followed by activated carbon treatment and drying of the residue

After the lysine has been separated off, 1 l of lysine fermentation broth is mixed with 250 g of solid calcium hydroxide on an ion exchanger. After stirring for 4 hours, the suspension is centrifuged in a laboratory centrifuge at 3000 g for 10 min. Using this procedure, 800 mL of a yellowish supernatant is obtained from the deep brown fermentation broth, which contains 7.6 g of the 8 g of trehalose originally used. 400 g of powdered activated carbon are added to further purify this supernatant. After 12- hourly incubation at RT, the activated carbon is separated off using a pleated filter. 650 ml of a slightly yellowish filtrate are obtained, which contains a total of 6.3 g of trehalose. Finally, the filtrate is freeze-dried. The remaining residue of 9.7 g has a trehalose content of 64.9% by weight.

Example 3

Enrichment of trehalose by precipitation with calcium hydroxide, filtration, subsequent activated carbon treatment and drying of the residue

In contrast to Example 2, the solids formed are separated off by filtration after the calcium hydroxide precipitation. This gives 730 mL of a yellowish-colored filtrate. The rest of the procedure is analogous to Example 2, whereby 8.7 g of dry residue with 66.2% by weight of trehalose can be obtained.

Example 4

Enrichment of trehalose by thermally induced precipitation, cross-flow filtration, subsequent activated carbon treatment and drying of the residue

Example 5

Enrichment of trehalose by precipitation with calcium hydroxide, centrifugation followed by activated carbon treatment and drying of the residue (broth from new work-up)

After the lysine has been separated off, 1 l of lysine fermentation broth is mixed with 100 g of solid calcium hydroxide on an ion exchanger (trehalose content: 11 g / L). After stirring for 4 hours, the suspension is centrifuged in a laboratory centrifuge at 3000 g for 10 min. 20 g of activated carbon are added to the 800 mL of a dark brown supernatant obtained in this way and incubated at RT for 19 h. The activated carbon is separated by filtration. The filtrate contains 8.9 g trehalose. Evaporation in vacuo gives 72.6 g of a dark brown, sticky residue with a trehalose content of 10.4% by weight.

Example 6 Enrichment of trehalose by adsorption on activated carbon and desorption with methanol 100 mL of a fermentation broth containing trehalose (content 9.76 g / L) are shaken with 10 g activated carbon (CPG 12x40) for 16 h at RT. After suction through a slotted sieve, the activated carbon is shaken with 100 mL methanol for 60 h at RT. After filtering off again, the filtrate is evaporated to dryness on a rotary evaporator. The brown residue of 1.1 g contains 300 mg trehalose (27% by weight).

Example 7

Enrichment of trehalose by adsorption on activated carbon and desorption with ethanol under cooling crystallization

300 mL of a trehalose solution (content 9.25 g L) are shaken with 20 g activated carbon at RT for 18 h. After suction through a slotted sieve, activated carbon is mixed with 300 mL ethanol and stirred under reflux for 15 h. The activated carbon is filtered off hot and the filtrate is cooled to 0-5 ° C., during which the trehalose crystallizes out. After suction, 1.3 g of trehalose are obtained as light gray crystals, the filtrate is evaporated to dryness on a rotary evaporator and contains 0.1 g of trehalose as white crystals.

After filtration, the activated carbon is shaken for 16 h at RT with 300 mL MeOH, filtered off and the filtrate is concentrated on a rotary evaporator, thereby obtaining a further 0.5 g of trehalose as almost white crystals.

Example 8

Enrichment of trehalose by adsorption on silica gel and desorption with methanol

100 ml of a fermentation broth containing trehalose (content 14 g / L) are shaken with 10 g of silica gel (MR3482) at RT for 19 h. After suctioning off through a glass suction filter, the silica gel is shaken with 100 mL methanol for 16 h at RT. After filtering off again, the filtrate is evaporated to dryness on a rotary evaporator. The brown residue of 1.5 g contains 110 mg trehalose (7% by weight).

Claims

claims

1. A process for the enrichment of trehalose from solutions, in which the enrichment is carried out with the aid of an adsorbent, characterized in that the adsorbent is an aluminosilicate.

2. The method according to claim 1, characterized in that the aluminosilicate is a zeolite.

3. The method according to claim 1 or 2, characterized in that the trehalose is adsorbed on the aluminosilicate.

4. The method according to any one of claims 2 to 3, characterized in that the zeolite is selected from the group consisting of FAU, BEA, DON, EMT, CFI, MOR, MAZ, and OFF.

5. The method according to any one of claims 1 to 4, characterized in that the adsorbent is used in the course of a chromatographic process.

6. The method according to any one of claims 1 to 5, characterized in that the solution comes from an enzymatic trehalose synthesis.

7. A process for the enrichment of trehalose from fermentation broths, comprising the steps of separating solids and enriching the trehalose with the aid of an adsorbent, characterized in that the adsorbent is an aluminosilicate.

8. The method according to claim 7, characterized in that the aluminosilicate is a zeolite.

9. The method according to claim 7, characterized in that at least one other product of value apart from trehalose is separated from the fermentation broth.

10. The method according to any one of claims 7 to 9, characterized in that the fermentation broth from a fermentation with at least one microorganism from the group consisting of Saccharomyces spec, Candida spec, Escherichia coli, Corynebacterium spec, Corynebacterium glutamicum, Pseudomonas spec, Nocardia spec, Brevibacterium spec, Arthrobacter spec, Stereptomyces spec, Microbacterium spec, Aspergillus spec, Bacillus spec, Pichia spec. and Filobasidium spec. comes.

11. The method according to any one of claims 7 to 10, characterized in that the trehalose is present in the fermentation broth in a concentration of less than 15 percent by weight measured on the dry weight of the fermentation broth.

12. The method according to any one of claims 1 to 11, characterized in that the method comprises at least one further step from the group consisting of activated carbon treatment, ultrafiltration, and ion exchange treatment.