RU2428482C2 - Method of preparing composition with improved rheological properties (versions) and composition obtained using said methods - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: methods involve obtaining a bacterial cellulose product through fermentation, possible lysis of bacterial cells from the bacterial cellulose product, mixing it with at least one polymeric thickener or precipitating agent and coprecipitation of the obtained mixture with alcohol. The bacterial cell lysis step can be performed after mixing with the precipitating agent. The polymeric thickener used can be at least one charged cellulose ester, at least one precipitating agent or combination thereof. The composition obtained using said method, having improved rheological properties and containing bacterial cellulose, has viscosity of at least 300 cP (300 mPa·s) and tensile yield 1.0 dine/cm² (0.1 N/m) when more than 0.36 wt % of it is put into a 500 ml water sample and after application of not more than two passages in an extensional homogeniser at pressure 1500 lb/in² (10342.5 kPa).

EFFECT: improved rheological properties of the composition.

31 cl, 20 ex

Description

Field of Invention

The present invention relates, in general, to a new method for producing bacterial cellulose compositions that exhibit improved viscosity modification properties, especially with the low energy consumption required to achieve viscosity changes. This method involves a new coprecipitation with a water-soluble co-agent, allowing precipitation in the presence of an excess of alcohol to form an insoluble fiber, which can then be used as a thickener or suspending agent without the need for a mixing step requiring high energy consumption. Such properties of bacterial cellulose were obtained in the past, but exclusively in methods requiring extremely high labor and energy costs. The method proposed according to the invention, thus, provides a composition containing bacterial cellulose, which not only exhibits the same effective properties as the previous types of bacterial cellulose, but also demonstrates some improved properties compared to the previous types. Some practical compositions and applications, including these new compositions containing bacterial cellulose, are also included in the scope of this invention.

State of the art

Bacterial cellulose is a broad category of polysaccharides exhibiting extremely desirable properties, although these compounds have essentially the same chemical structure as celluloses derived from plant material. However, as the name suggests, the source of these polysaccharides is bacterial in nature (mainly, it is produced by microorganisms of the genus Acetobacter), which is the result of fermentation, purification and isolation. Such bacterial cellulose compounds consist of very thin cellulose fibers having unique sizes and their ratio (with a diameter of from about 40 to 100 nm each and a length of from 0.1 to 15 microns) in the form of a beam (with a diameter of from 0.1 to 0, 2 microns on average). Such an intertwined structure of the beams forms a network structure that facilitates swelling in an aqueous solution, thereby creating excellent three-dimensional network structures. These three-dimensional structures carry out a suitable and desired viscosity modification and also contribute to suspension by creating a yield strength system in the target fluid and provide excellent bulk viscosity. As a result of this, highly effective suspensions of materials (such as food products, as an example) are formed, which tend to settle over time from solution, especially from aqueous solutions. In addition, such bacterial cellulose compositions help prevent precipitation and separation of instant liquid food products (e.g., soups, chocolate drinks, yogurt, juices, dairy products, cocoa and the like), despite the need for relatively large amounts of energy to be consumed during mixing or heating to initially achieve the desired level of suspension of such foods.

The fibers obtained as a result (and, accordingly, bundles) are insoluble in water and, possessing the features indicated above, exhibit the properties of polyhydric alcohols and water-absorbing properties. One particular type of bacterial cellulose, microfibrillar cellulose, is usually produced in an uncharged state and has the ability to bind without any effects. However, without such additional additives for the purpose of thickening or any other viscosity modification, it was shown that the obtained systems themselves demonstrate a high degree of instability, especially over time, associated with typical requirements for shelf life of food products. As a result, certain co-agents, such as carboxymethyl cellulose (CMC), also known as cellulose gum, were introduced into bacterial cellulose products by adsorption on its fibers, followed by spray drying (without any coprecipitation steps) to provide improved stabilization and dispersion, most likely due to the presence of negative charges on the CMC, independently transferred to the fibers of bacterial cellulose. Such charges, thus, seem to impart the ability to repel, preventing the fiber bundles from weakening the formed network. It is known that even with this possibility, the choice of the appropriate CMC to a large extent affects the resulting rheological properties of the target bacterial cellulose due to a certain sensitivity to the salts and acids of some CMC products. Therefore, although improvements in the use of bacterial cellulose with similar CMC inclusions have been achieved in the past, care must be taken to ensure that the proper pH and salt conditions are appropriate for the entire composition. In connection with the foregoing, further improvements are of great interest to interested industries, which would lead to greater reliability of the use of bacterial cellulose in many areas.

In addition, although such bacterial cellulose is of undoubted interest and importance for ensuring effective rheological modifications in food products based on liquid, for the reasons mentioned above, it turned out that the costs associated with the production of such cellulosic materials are very high, especially in parts of the necessary labor and waste problems. Fermentation of such materials initially gives a very low yield. Typically, the production process for purifying and isolating such bacterial cellulosic materials upon completion of the fermentation entails a series of cumbersome steps in order to obtain a wet cake with a significant amount of bacterial cellulosic product, compared to the initial fermentation. Further spray drying may also affect the final yield by isolating bacterial cellulose during the production of the powder.

Such additional steps not only require intensive labor and energy, but also lead to large amounts of wastewater and waste that need to be disposed of and recycled. In this regard, it was found that the cost of producing bacterial cellulose (in particular microfibrillar cellulose), compared with other gums, is excessively high, which limits the use of such a product to a specific desired practical area. To date, an effective method has not been developed that would eradicate these problems, and there is no way that would ultimately give the bacterial cellulosic material improved properties for the intended use compared to materials obtained by the aforementioned traditional production method.

Brief Description of the Invention

Accordingly, this invention encompasses a method for producing a composition containing bacterial cellulose, comprising the steps of: a) producing a bacterial cellulose product by fermentation, b) possibly lysing the bacterial cells from the obtained bacterial cellulose product, c) mixing said bacterial cellulose product obtained from step a) "or" b "with a polymer thickener selected from the group consisting of at least one charged cellulose ether, at least one precipitated its agent, and any combination thereof, and d) the coprecipitation of the mixture of step "c" water-immiscible non-aqueous liquid (such as an alcohol as a non-limiting example). A possible charged cellulose ether from step “C” is a compound used to disperse and stabilize the network in the final finished compositions to which this composition containing bacterial cellulose is added. Charged compounds facilitate, as mentioned above, the ability to form the necessary network of fibers due to the repulsion of individual fibers. A possible precipitating agent from step "B" is a compound used to maintain the functional properties of the mesh fiber of bacterial cellulose during drying and grinding. Examples of such charged cellulose ethers include those cellulose-based compounds that have a total positive or negative charge, and include, without limitation, any sodium carboxymethyl cellulose (CMC), cationic hydroxyethyl cellulose, and the like. The precipitating (drying) agent is selected from the group of natural and / or synthetic products, including, without limitation, xanthan gum, pectin, alginates, gellan gum, velan gum, diutan gum, ramzan gum, carrageenan, guar gum, agar, gum arabic, gum arabic gum, karaya gum, tragacanth gum, tamarind gum, locust bean gum and the like. The precipitating (drying) agent is included preferably, but not necessarily, for reasons related to its ability to reactivate bacterial cellulose after spray drying before being introduced into the target liquid, the rheological properties of which are modified in this way. Therefore, one more specific method encompassed by this invention includes the steps of: a) producing a bacterial cellulosic product by fermentation, b) possibly lysing the bacterial cells from the bacterial cellulosic product, c) mixing said obtained bacterial cellulosic product from step a or step "b" with biological gum (which when introduced as a culture fluid (fermentation broth) has bacterial cells, preferably lysed from it), and d) coprecipitation of the mixture from stage "c", miscible with water, non-aqueous liquid. Alternatively, such a specific method may comprise the steps of: a) producing a bacterial cellulosic product by fermentation, b) mixing said bacterial cellulosic product with biological gum, c) co-lysing the mixture from step “b” to remove bacterial cells from it, and g) coprecipitation of the mixture from stage "C", miscible with water, non-aqueous liquid. The resulting coprecipitation product is presented in the form of a filter cake, which can then be dried, and the particles thus obtained can then be crushed to the desired size. Moreover, for some purposes, these particles can be further mixed with another hydrocolloid, such as carboxymethyl cellulose (CMC), to impart certain properties. Additionally, the product of the invention should be defined as a composition comprising bacterial cellulose comprising at least one bacterial cellulosic material and at least one polymer thickener selected from the group consisting of at least one charged cellulose ether, at least one precipitating agent selected from the group consisting of xanthan products, pectin, alginates, gellan gum, velan gum, diutan gum, ramzan gum, carrageenan, guar gum, agar , Arabian gum, ghatti gum, gum karaya, tragacanth gum, tamarind gum, locust bean gum and the like and any mixtures thereof, wherein said composition has a viscosity characteristic of at least 300 cP (300 mPa · s) and a yield strength of 1 , 0 dyne / cm ² (0.1 N / m) when placed in an amount of not more than 0.36% by weight in a 500 ml sample of water and after application in an extensional homogenizer at a pressure of 1,500 psi. inch (10342.5 kPa) no more than two passes.

As one potentially preferred embodiment, this bacterial cellulose and xanthan composition obtained by this method has a distinct advantage in that it facilitates activation without intensive labor and energy costs. Another clear advantage of this method is the ability to collect the resulting composition containing bacterial cellulose by precipitation with isopropyl alcohol or with a charged cellulose ether, or with a precipitating agent (drying agent) present in it. Thus, since this bacterial cellulose is coprecipitated by the method described above, it can be expected without adhering to any particular scientific theory that an alcohol-insoluble polymer thickener (such as xanthan or sodium CMC) appears to protect bacterial cellulose , forming a coating of at least part of the formed fibers. In this case, apparently, the polymer thickener really helps the cellulose fibers bind and undergo drying due to the addition of a non-aqueous liquid (preferably, such as low-alkyl alcohols), thus resulting in the collection of significant amounts of this polysaccharide at this stage of coprecipitation, which usually has a low exit. The exclusion of significant amounts of water during the stages of purification and isolation, thus leads to large quantities of bacterial cellulose in the end. Using this new method, it is possible to collect the largest amount of fermented bacterial cellulose, while ensuring high profitability of the production of the desired product, as well as eliminating waste water, as mentioned above, and the multiple stages of drainage and resuspension, which are typically necessary to obtain the desired product. Moreover, as noted earlier, the presence of a drying agent, in particular a xanthan product, as one non-limiting example, as a coating of at least part of the bundles of bacterial cellulose fibers, when included in the target final composition, apparently leads to an improvement in conditions required to activate. Unexpected is the fact that there is a noticeable decrease in the energy consumption necessary to achieve the desired modification of the rheological properties of the composition containing bacterial cellulose according to the invention compared to previously practiced products of this type. In addition, since bacterial cellulose (ie microfibrillar cellulose, hereinafter referred to as “MFC”) has unique functional and rheological properties compared to soluble polymer thickener as such, the final product obtained by the method of the invention, as opposed to typical methods , allows to reduce costs by improving the conditions of reactivation, resistance to viscosity changes during high-temperature processing of food products and improving suspension properties during a long shelf life.

DETAILED DESCRIPTION OF THE INVENTION

For the purposes of this invention, the term “composition containing bacterial cellulose” is intended to encompass the bacterial cellulose product as prepared according to the method of the invention and, accordingly, comprising a xanthan product covering at least a portion of the obtained bundles of bacterial cellulose fibers . It is implied, therefore, that the term "composition" means that the product produced from it is a combination of bacterial cellulose and xanthan, obtained by this method and having such a final structure and configuration. The term "bacterial cellulose" encompasses any type of cellulose obtained by fermentation of bacteria of the genus Acetobacter, and includes materials commonly referred to as microfibrillar cellulose, net bacterial cellulose and the like.

As noted above, bacterial cellulose can be used in various compositions as an effective rheological modifier. When dispersed in liquids, such materials form thixotropic mixtures with high viscosity and a high yield strength. Yield strength is a measure of the force required to initiate a flow in a gel-like system. It indicates the ability of a liquid to suspend, as well as the ability of a given liquid to remain in situ after application to a vertical surface.

Typically, this rheological modification behavior provides some degree of processing for a mixture of bacterial cellulose in a hydrophilic solvent such as water, polyhydric alcohols (e.g. ethylene glycol, glycerin, polyethylene glycol and so on) or mixtures thereof. This treatment is called “activation” and typically involves high pressure homogenization and / or high shear mixing. However, it was found that compositions of the invention containing bacterial cellulose can be activated by mixing at low energy costs. Activation is a process in which the three-dimensional structure of cellulose is modified in such a way that the cellulose attaches its functional properties to the main solvent or solvent mixture where the activation takes place, or to the composition to which the activated cellulose is added. Functional properties include providing properties such as a thickening property that determines yield strength, heat resistance, suspension qualities, multiple freeze stability, flow control, foam stabilization, coating and film formation and the like. The treatment that occurs during the activation process has a significantly greater effect than simply dispersing cellulose in a basic solvent. This treatment “pulps” the cellulose fibers so that they increase in volume. A composition containing bacterial cellulose can be used in the form of a wet suspension (dispersion) or a dry product, which is obtained by drying the dispersion with well-known drying methods, such as spray or freeze drying, to impart the desired rheological advantages of the target liquid composition. Activation of bacterial cellulose (such as MFC or net bacterial cellulose) increases the portion of the cellulose in volume to create a net formation of closely interwoven fibers with a very high surface area. This activated net bacterial cellulose has an extremely high surface area, which is believed to be at least 200 times larger than traditional microcrystalline cellulose (i.e., plant cellulose).

The bacterial cellulose used according to the invention can be of any type associated with the fermentation product of microorganisms of the genus Acetobacter, and could previously be available, for example, from CPKelco U.S. under the trade name CELLULON®. Such products obtained by aerobic cultivation are characterized by a high-net branched, intertwined structure of water-insoluble fibers.

The production of such bacterial cellulose products is well known. For example, US Pat. No. 5,079,162 and US Pat. No. 5,144,021, which are incorporated herein by reference, disclose a method and medium for aerobic production of net bacterial cellulose under conditions of mixing a culture medium using the bacterial strain Acetobacter aceti war. xylinum. The use of the mixing conditions of the culture medium leads to the continuous production of the desired cellulose for an average of more than 70 hours, at least in an amount of 0.1 g / l per hour. Mesh pulp in the form of a wet cake containing about 80-85% water can be obtained using the methods and conditions described in the above patents. Dry mesh bacterial cellulose can be obtained using drying methods such as spray drying or freeze drying, which are well known.

Acetobacter is a typical gram-negative rod-shaped bacterium ranging in size from 0.6-0.8 microns to 1.0-4 microns. This is a strictly aerobic microorganism, which means that the basis of metabolism is respiration, not fermentation. This bacterium is also recognized by its ability to produce multiple chains of poly-β-1,4-glucans chemically identical to cellulose. Chains of microcellulose, or microfibrils, reticular bacterial cellulose are synthesized on the surface of the bacterium, in areas external to the cell membrane. Typically, these microfibrils have cross-sectional sizes from about 1.6 nm to 5.8 nm. In contrast, under static or stopped culture conditions, microfibrils on the surface of bacteria combine to form fibrils, usually having cross-sectional sizes from about 3.2 nm to 133 nm. The small cross-sectional size of these fibrils produced by Acetobacter, together with the concomitant large surface and the inherent hydrophilicity of cellulose, gives a cellulosic product with an unusually high ability to absorb aqueous solutions. In combination with net bacterial cellulose, additives have often been used to promote the formation of stable viscous dispersions.

The above problems, inseparable from the purification and collection of such bacterial cellulose, have led to the determination that the method used here, to the necessary extent, provides excellent results. The first step of the general process is to produce any amount of the desired bacterial cellulose in fermented form. The production method for this step is described above. It has been proven that the yield of such a product is very difficult to generate at relatively high levels, so it is imperative to achieve the preservation of the target product in order to ultimately get the assembled product with the lowest cost.

Cleaning these materials is well known. Lysing of bacterial cells from a bacterial cellulosic product is achieved by the addition of alkali, such as sodium hydroxide, or any similar high pH additive (pH above about 12.5, preferably) in an amount sufficient to carefully remove as many bacterial cells from the cellulosic product as possible. If necessary, this can be carried out in more than one stage. This is usually followed by an acid neutralization step. Any acid suitable for the reaction can be used with a sufficiently low pH and corresponding molarity (and thus effectively neutralize or lower the pH of the product as close to 7.0 as possible). Sulfuric acid, hydrochloric acid and nitric acid are suitable examples for this step. A person skilled in the art can easily determine the appropriate reagent and its quantity for these purposes. Alternatively, cells can be lysed and degraded by enzymatic methods (lysozyme and protease treatment at the appropriate pH).

Next, the lysed product is mixed with a polymer thickener to effectively coat the target fibers and bundles of bacterial cellulose. The polymer thickener should not be soluble in alcohol (in particular, isopropyl alcohol). Such a thickener is either an aid to dispersing the bacterial cellulose in the target liquid composition, or an aid to drying the bacterial cellulose to more easily remove water from it, as well as a potential aid to dispersing or suspending these fibers in the target fluid composition. Suitable dispersing aids (agents) include, without limitation, CMC (various types), cationic HEC (hydroxyethyl cellulose) and so on; essentially any polymer compound in nature that has the necessary ability to disperse with respect to bacterial cellulose fibers when introduced into the target liquid solution. Preferably, such a dispersant is CMC, such as CEKOL® from CP Kelco. Suitable precipitating agents (agents), as noted previously, include any number of bio-gums, including xanthan gum products (such as KELTROL®, KELTROL T® and the like from CP Kelco), gellan gum, velan gum, diutan gum, ramzan gum, guar gum, locust bean gum and the like and other types of natural polymer thickeners such as pectin as a non-limiting example. Preferably, the polymer thickener is a xanthan product and is introduced and mixed with bacterial cellulose in the form of a broth. Basically, mixing the two products in a broth, in the form of a powder or in the form of a rehydrated powder, provides for the desired formation of a xanthan coating on at least a portion of the fibers and / or bundles of bacterial cellulose. In one embodiment, the broths of bacterial cellulose and xanthan are mixed after purification (lysis) of both in order to remove the remaining bacterial cells. In another embodiment, these broths can be mixed with each other without prior lysis, but co-lysed during mixing to effect such purification.

The amounts of each component in this method can vary greatly. For example, bacterial cellulose is typically present in an amount of from about 0.1% to about 5% by weight of the added polymer thickener, preferably from about 0.5 to about 3.0%, while the polymer thickener may be present in an amount ranging from 10 to about 900% by weight of bacterial cellulose.

After mixing and coating the bacterial cellulose with a polymer thickener, the resulting product is then collected by coprecipitation in a non-aqueous liquid miscible with water. Preferably, for reasons of toxicity, availability and cost, such a liquid is an alcohol, with isopropyl alcohol being most preferred. Other types of alcohols, such as ethanol, methanol, butanol and the like, can also be used, not to mention other water-miscible non-aqueous liquids such as acetone, ethyl acetate and any mixtures thereof. You can use any mixture of such non-aqueous liquids also for this stage of coprecipitation. Typically, the coprecipitated product is processed using a device for the separation of solid and liquid substances, which provides for the removal of alcohol-soluble components and the preservation of the desired composition containing bacterial cellulose.

From there, the product in the form of a wet cake is collected and then transferred to a dryer and then ground to obtain particles of a suitable size. To give additional properties and / or advantages to the wet cake or dried materials, additional co-agents can be added. These co-agents include polysaccharides derived from plants, algae or bacteria, and derivatives thereof, together with lower molecular weight carbohydrates such as sucrose, glucose, maltodextrin and the like. Other additives that may be present in the composition containing bacterial cellulose include, without limitation, hydrocolloid, polyacrylamides (and homologs), polyacrylic acids (and homologs), polyethylene glycol, poly (ethylene oxide), polyvinyl alcohol, polyvinylpyrrolidones, starch (and the like) molecules for sugars), modified starch, animal gelatin and uncharged cellulose ethers (such as carboxymethyl cellulose, hydroxyethyl cellulose and the like).

The compositions of the invention containing bacterial cellulose can then be incorporated into a variety of possible food compositions, including drinks, frozen foods, dairy products with cultures, and the like; non-food compositions such as household detergents, fabric conditioners, hair conditioners, hair styling products; or as stabilizers or agents used for the preparation of bitumen emulsions, pesticides, corrosion inhibitors in metalworking; in the production of latex, as well as in the processing of paper and non-woven materials; they can find application in biomedicine, as pharmaceutical excipients, components of hydrocarbon-based drilling fluids, and so on. Liquid compositions, including the composition according to the invention, obtained as described above, may include such compositions containing bacterial cellulose in an amount of from about 0.01% to about 1% by weight and preferably from about 0.03% to about 0.5% by weight of the total weight of the given liquid composition. The resulting composition containing bacterial cellulose should impart a viscosity modification to a 500 ml sample of water (when added in an amount of not more than 0.36% by weight) of at least 300 cP (300 mPa · s), as well as a yield strength in the same test sample of at least 1.0 dyne / cm ² (0.1 N / m).

Preferred Embodiments

The following non-limiting examples demonstrate the doctrines of the various methods encompassed by this invention.

Example 1

MFC was obtained in a 1200 gallon (4542.5 L) fermenter with a final yield of 1.49% (mass). The broth was treated with 350 million ^-1 hypochlorite and subsequently treated with 70 million ^-1 lysozyme and 194 million ^-1 protease. A portion of the MFC-treated broth was mixed with a predetermined amount of xanthan gum broth (MFC / XG = 2/1, dry matter) and the resulting mixture was then precipitated with isopropyl alcohol (85%) to obtain a filter cake. Then, a portion of the filter cake was dried in an oven at 70 ° C for 2 h and ground in a Brinkmann mill to 60 mesh. Next, the powdered composition was introduced into a solution (500 ml) of standard tap water (STW, 2.782 g of CaCl ₂ · 2H ₂ O and 18.927 g of NaCl were dissolved in 5 gallons (18.927 l) of deionized water) in an amount of about 0.36% by weight moreover, carboxymethyl cellulose (CMC) was simultaneously added in an amount of 20% by weight (resulting in 0.288% MFC / xanthan and 0.072% CMC), and the composition was then mixed in a Silverson mixer at 8000 rpm for 10 minutes. The viscosity of the product (measured with a Brookfield viscometer, 61 spindles at 5 rpm for 1 min) and yield strength were 1176 cP (1176 mPa · s) and 4.91 dyn / cm ² (0.491 N / m), respectively.

After that, 210 ml of the obtained activated MFC solution (0.36%) was mixed in one beaker with 15.5 g of fractionated sand (after 60 mesh, but into 80 mesh) and stirred for 1 min. In a separate beaker of another 210 ml, a sample of the resulting activated MFC solution was then mixed with 15.5 g of fine-grained CaCO ₃ and stirred for 1 min. The contents of each glass were then poured into separate graduated cylinders with a volume of 100 ml and brought to the level of 100 ml in each cylinder. In each case, these solutions showed excellent suspension properties, and a solid (either sand or calcium carbonate) did not precipitate from the target solutions. Then, graduated cylinders were stored at room temperature (22-25 ° C) for 24 hours to determine whether deposition occurred during this period of time. In each sample, after 24 hours, the phase separation for the samples both from above and from the bottom was less than 10% (according to visual assessment), which indicated the excellent properties of long-term suspensions.

Example 2

MFC was obtained in a 1200 gallon (4542.5 L) fermenter with a final yield of 1.49% (mass). The broth was treated with 350 million ^-1 hypochlorite and subsequently treated with 70 million ^-1 lysozyme and 194 million ^-1 protease. A portion of the MFC treated broth was mixed with a predetermined amount of xanthan gum broth (MFC / XG = 3/1, dry matter) at high shear and the resulting mixture was then precipitated with isopropyl alcohol (85%) to obtain a filter cake. This filter cake was dried and pulverized as in Example 1. Then, the pulverized composition was introduced into the STW sample in an amount of about 0.36% by weight, while carboxymethyl cellulose (CMC) was added in an amount of 20% by weight, and the composition was then mixed in a Silverson mixer at 8000 rpm for 10 minutes The viscosity of the product and the yield strength were 709 cP (709 MPa · s) and 1.96 dyne / cm ² (0.196 N / m), respectively.

Example 3

MFC was obtained in a 1200 gallon (4542.5 L) fermenter with a final yield of 1.49% (mass). The broth was treated with 350 million ^-1 hypochlorite and subsequently treated with 70 million ^-1 lysozyme and 194 million ^-1 protease. A portion of the MFC-treated broth was mixed with a predetermined amount of xanthan gum broth (MFC / XG = 4/1, dry matter) at high shear and the resulting mixture was then precipitated with isopropyl alcohol (85%) to obtain a filter cake. This filter cake was dried and pulverized as in Example 1. Then, the pulverized composition was introduced into the STW sample in an amount of about 0.36% by weight, while carboxymethyl cellulose (CMC) was added in an amount of 20% by weight, and the composition was then mixed in a Silverson mixer at 8000 rpm for 10 minutes The viscosity of the product and the yield strength were 635 cP (635 MPa · s) and 1.54 dyn / cm ² (0.154 N / m), respectively.

Example 4

MFC was obtained in a 1200 gallon (4542.5 L) fermenter with a final yield of 1.49% (mass). The broth was treated with 350 million ^-1 hypochlorite and subsequently treated with 70 million ^-1 lysozyme and 194 million ^-1 protease. A portion of the MFC treated broth was mixed with a predetermined amount of xanthan gum broth (MFC / XG = 3/1, dry matter) at high shear and the resulting mixture was then precipitated with isopropyl alcohol (85%) to obtain a filter cake. This filter cake was then dried and ground, as in Example 1. Then, the powdered composition was introduced into the STW sample in an amount of about 0.36% by weight, while carboxymethyl cellulose (CMC) was added in an amount of 10% by weight, and the composition then mixed in a Silverson mixer at 8000 rpm for 10 minutes The viscosity of the product and the yield strength were 1242 cP (1242 MPa · s) and 4.5 dyn / cm ² (0.45 N / m), respectively.

Example 5

MFC was obtained in a 1200 gallon (4542.5 L) fermenter with a final yield of 1.49% (mass). The broth was treated with 350 million ^-1 hypochlorite and subsequently treated with 70 million ^-1 lysozyme and 194 million ^-1 protease. A portion of the MFC-treated broth was mixed with a predetermined amount of xanthan gum broth (MFC / XG = 3/1, dry matter) and the resulting mixture was then precipitated with isopropyl alcohol (85%) to obtain a filter cake. This filter cake was then dried and ground, as in Example 1. Then, the powdered composition was introduced into the STW sample in an amount of about 0.36% by weight, while carboxymethyl cellulose (CMC) was added in an amount of 20% by weight, and the composition then mixed in a Silverson mixer at 8000 rpm for 10 minutes The viscosity of the product and the yield strength were 1242 cP (1242 MPa · s) and 4.5 dyn / cm ² (0.45 N / m), respectively.

Example 6

MFC was obtained in a 1200 gallon (4542.5 L) fermenter with a final yield of 1.49% (mass). The broth was treated with 350 million ^-1 hypochlorite and subsequently treated with 70 million ^-1 lysozyme and 194 million ^-1 protease. A portion of the MFC-treated broth was mixed with a predetermined amount of xanthan gum broth (MFC / XG = 3/1, dry matter) and the resulting mixture was then precipitated with isopropyl alcohol (85%) to obtain a filter cake. This filter cake was then dried and ground, as in Example 1. Then, the powdered composition was introduced into the STW sample in an amount of about 0.36% by weight, while carboxymethyl cellulose (CMC) was added in an amount of 20% by weight, and the composition then activated in an extensional homogenizer at a pressure of 1500 psi. inch (10342.5 kPa) for two passes. The viscosity of the product and the yield strength were 1010 cP (1010 MPa · s) and 1.76 dyne / cm ² (0.176 N / m), respectively.

Example 7

MFC was obtained in a 1200 gallon (4542.5 L) fermenter with a final yield of 1.93% (mass). The broth was treated with 350 million ^-1 hypochlorite and subsequently treated with 70 million ^-1 lysozyme and 194 million ^-1 protease. A portion of the MFC-treated broth was mixed with a predetermined amount of xanthan gum broth (MFC / XG = 3/1, dry matter) and the resulting mixture was then precipitated with isopropyl alcohol (85%) to obtain a filter cake. This filter cake was then dried and pulverized as in Example 1. Then, the pulverized composition was introduced into the STW sample in an amount of about 0.36% by weight, while carboxymethyl cellulose (CMC) was added in an amount of 20%, and the composition was then mixed in a Silverson mixer at 8000 rpm for 5 minutes The viscosity of the product and the yield strength were 690 cP (690 MPa · s) and 2.19 dyne / cm ² (0.219 N / m), respectively.

Example 8

MFC was obtained in a 1200 gallon (4542.5 L) fermenter with a final yield of 1.93% (mass). The broth was treated with 350 million ^-1 hypochlorite and subsequently treated with 70 million ^-1 lysozyme and 194 million ^-1 protease. A portion of the MFC-treated broth was mixed with a predetermined amount of xanthan gum broth and CMC solution (MFC / XG / CMC = 3/1/1, dry matter) and the resulting mixture was then precipitated with isopropyl alcohol (85%) to obtain a filter cake . This filter cake was then dried and pulverized as in Example 1. Then, the pulverized composition was introduced into the STW sample in an amount of about 0.36% by weight, and the composition was then mixed in a Silverson mixer at 8000 rpm for 5 minutes . The viscosity of the product and the yield strength were 1057 cP (1057 mPa · s) and 3.65 dyne / cm ² (0.365 N / m), respectively.

Example 9

MFC was obtained in a 1200 gallon (4542.5 L) fermenter with a final yield of 1.93% (mass). The broth was treated with 350 million ^-1 hypochlorite and subsequently treated with 70 million ^-1 lysozyme and 194 million ^-1 protease. A portion of the MFC-treated broth was mixed with a predetermined amount of pectin solution (MPC / pectin = 6/1, dry matter) and the resulting mixture was then precipitated with isopropyl alcohol (85%) to obtain a filter cake. This filter cake was dried and pulverized as in Example 1. Then, the pulverized composition was introduced into the STW sample in an amount of about 0.36% by weight, while carboxymethyl cellulose (CMC) was added in an amount of 20% by weight, and the composition was then mixed in a Silverson mixer at 8000 rpm for 5 minutes The viscosity of the product and the yield strength were 377 cP (377 MPa · s) and 1.06 dyne / cm ² (0.106 N / m), respectively.

Example 10

MFC was obtained in a 1200 gallon (4542.5 L) fermenter with a final yield of 1.93% (mass). The broth was treated with 350 million ^-1 hypochlorite and subsequently treated with 70 million ^-1 lysozyme and 194 million ^-1 protease. A portion of the MFC-treated broth was mixed with a predetermined amount of CMC solution (MFC / CMC = 3/1, dry) and the resulting mixture was then precipitated with isopropyl alcohol (85%) to obtain a filter cake. This filter cake was dried and pulverized as in Example 1. Then, the pulverized composition was introduced into the STW sample in an amount of about 0.36% by weight, and the composition was then mixed in a Silverson mixer at 8000 rpm for 5 minutes. The viscosity of the product and the yield strength were 432 cP (432 MPa · s) and 1.39 dyne / cm ² (0.139 N / m), respectively.

Example 11

MFC was obtained in a 1200 gallon (4542.5 L) fermenter with a final yield of 1.93% (mass). The broth was treated with 350 million ^-1 hypochlorite and subsequently treated with 70 million ^-1 lysozyme and 194 million ^-1 protease. A portion of the MFC-treated broth was mixed with a predetermined amount of pectin and CMC solutions (MPC / pectin / SMS = 6/1/2, dry matter) and the resulting mixture was then precipitated with isopropyl alcohol (85%) to obtain a filter cake. This filter cake was dried and pulverized as in Example 1. Then, the pulverized composition was introduced into the STW sample in an amount of about 0.36% by weight, and the composition was then mixed in a Silverson mixer at 8000 rpm for 5 minutes. The viscosity of the product and the yield strength were 552 cP (552 MPa · s) and 1.74 dyne / cm ² (0.174 N / m), respectively.

Example 12

MFC was obtained in a 1200 gallon (4542.5 L) fermenter with a final yield of 1.51% (mass). The broth was treated with 350 million ^-1 hypochlorite and subsequently treated with 70 million ^-1 lysozyme and 350 million ^-1 protease followed by additional 350 million ^-1 hypochlorite. A portion of the MFC-treated broth was mixed with a predetermined amount of broth with xanthan gum (MFC / XG = 2/1, on dry matter), then precipitated with isopropyl alcohol (85%), dried and crushed, as in example 1. Then, the crushed powder was introduced into an STW solution in an amount of about 0.2% by weight, while carboxymethyl cellulose (CMC) was added in an amount of 10% by weight, and the composition was then activated in an extensional homogenizer at a pressure of 1,500 psi. inch (10342.5 kPa) for two passes. The viscosity of the product at 6 rpm was 377 cP (377 mPa · s).

Example 13

MFC was obtained in a 1200 gallon (4,542.5 L) fermenter with a final yield of 1.6% (mass). The broth was treated with 350 million ^-1 hypochlorite and subsequently treated with 70 million ^-1 lysozyme and 350 million ^-1 protease followed by additional 350 million ^-1 hypochlorite. A portion of the MFC-treated broth was mixed with a predetermined amount of broth with xanthan gum (MFC / XG = 2/1, on dry matter), then precipitated with isopropyl alcohol (85%), dried and crushed, as in example 1. Then, the crushed powder was introduced into a solution of deionized water, a solution of STW and a 0.25% solution of CaCl ₂ , respectively, in an amount of about 0.2% by weight, with the addition of carboxymethyl cellulose (CMC) in an amount of 10% by weight, and the composition was then activated in an extensional homogenizer at pressure 1,500 psi inch (10342.5 kPa) for two passes. The viscosity of the product was 512 cP (512 mPa · s), 372 cP (372 mPa · s) and 358 cP (358 mPa · s) in deionized water, STW and 0.25% CaCl ₂ solution, respectively.

By analogy with the test in Example 1, in this test, approximately 20 nylon granules with a diameter of 3.2 mm (each had a density of about 1, were dropped into each of the solutions (in deionized water, STW, or 0.25% CaCl ₂ solution) 14 g / ml) and the solutions were left at room temperature for 24 hours. None of the granules settled to the bottom of the beakers after the elapsed time period, thus indicating the excellent properties of the long-term suspension.

Example 14

MFC was obtained in a 1200 gallon (4542.5 L) fermenter with a final yield of 1.51% (mass). The broth was treated with 350 million ^-1 hypochlorite and subsequently treated with 70 million ^-1 lysozyme and 350 million ^-1 protease followed by additional 350 million ^-1 hypochlorite. A portion of the MFC-treated broth was mixed with a predetermined amount of broth with xanthan gum (MFC / XG = 2/1, on dry matter), then precipitated with isopropyl alcohol (85%), dried and crushed, as in example 1. Then, the crushed powder was introduced to a sample of deionized water in an amount of about 0.2% by weight, with the simultaneous addition of carboxymethyl cellulose (CMC) in an amount of 10% by weight, and the composition was then activated in a mixer with a propeller stirrer at 2500 rpm for 10 minutes. The viscosity of the product was 185 cP (185 MPa · s).

Example 15

MFC was obtained in a 1200 gallon (4,542.5 L) fermenter with a final yield of 1.4% (mass). The broth was treated with 350 million ^-1 hypochlorite and subsequently treated with 70 million ^-1 lysozyme and 350 million ^-1 protease followed by additional 350 million ^-1 hypochlorite. A portion of the MFC-treated broth was mixed with a predetermined amount of broth with xanthan gum and a solution pre-hydrated with CMC (MFC / XG / CMC = 6/3/1, dry matter), then precipitated with isopropyl alcohol (85%), dried and crushed as in Example 1. Then, the powdered composition was introduced into an STW solution and a 0.25% CaCl ₂ solution, respectively, in an amount of about 0.2% by weight, and the composition was then activated in an extensional homogenizer at a pressure of 1500 psi. inch (10342.5 kPa) for two passes. The viscosity of the product at 6 rpm was 343 cP (343 mPa · s) and 334 cP (334 mPa · s) in STW and 0.25% CaCl ₂ , respectively. About 20 nylon granules with a diameter of 3.2 mm (1.14 g / ml) were dropped into each solution (in STW or 0.25% CaCl ₂ solution) and the solutions were left at room temperature for 24 hours. None of the granules settled to the bottom of the beakers after a period of 24 hours.

Example 16

MFC was obtained in a 1200 gallon (4,542.5 L) fermenter with a final yield of 1.6% (mass). The broth was treated with 350 million ^-1 hypochlorite and subsequently treated with 70 million ^-1 lysozyme and 350 million ^-1 protease followed by additional 350 million ^-1 hypochlorite. A portion of the MFC-treated broth was mixed with a predetermined number of solutions of pre-hydrated pectin and CMC (MFC / pectin / CMC = 6/3/1, dry matter), then precipitated with isopropyl alcohol (85%), dried and crushed, as in example 1. Then, the powdered composition was introduced into an STW solution and 0.25% CaCl ₂ solution, respectively, in an amount of about 0.2% by weight, and the composition was then activated in an extension homogenizer at a pressure of 1500 psi. inch (10342.5 kPa) for two passes. The viscosity of the product at 6 rpm was 306 cP (306 mPa · s) and 293 cP (293 mPa · s) in STW and 0.25% CaCl ₂ , respectively. About 20 nylon granules with a diameter of 3.2 mm (1.14 g / ml) were dropped into each solution (in STW or 0.25% CaCl ₂ solution) and the solutions were left at room temperature for 24 hours. None of the granules settled to the bottom of the beakers after a period of 24 hours.

Example 17

MFC was obtained in a 1200 gallon (4,542.5 L) fermenter with a final yield of 1.6% (mass). The broth was treated with 350 million ^-1 hypochlorite and subsequently treated with 70 million ^-1 lysozyme and 350 million ^-1 protease followed by additional 350 million ^-1 hypochlorite. A portion of the MFC-treated broth was mixed with a predetermined amount of solution pre-hydrated with CMC (MFC / CMC = 3/1, dry matter), then precipitated with isopropyl alcohol (85%), dried and ground, as in Example 1. Then, the powder composition was ground introduced into the STW solution and a 0.25% solution of CaCl ₂ , respectively, in an amount of about 0.2% by weight, and the composition was then activated in an extensional homogenizer at a pressure of 1500 psi. inch (10342.5 kPa) for two passes. The viscosity of the product was at 6 rpm 206 cP (206 MPa · s) and 202 cP (202 MPa · s) in STW solution and 0.25% CaCl ₂ solution, respectively. About 20 nylon granules with a diameter of 3.2 mm (1.14 g / ml) were dropped into each solution (in STW or 0.25% CaCl ₂ solution) and the solutions were left at room temperature for 24 hours. None of the granules settled to the bottom of the beakers after a period of 24 hours.

Example 18

MFC was obtained in a 1200 gallon (4542.5 L) fermenter with a final yield of 1.54% (mass). The broth was treated with 350 million ^-1 hypochlorite and subsequently treated with 70 million ^-1 lysozyme and 350 million ^-1 protease followed by additional 350 million ^-1 hypochlorite. A portion of the MFC-treated broth was mixed with a predetermined amount of broth with Diutan (MPC / Diutan = 2/1, on dry matter), then precipitated with isopropyl alcohol (85%), dried and crushed, as in example 1. Then, the powdered composition was introduced into a solution of deionized water in an amount of about 0.2% by weight, with the simultaneous addition of carboxymethyl cellulose (CMC) in an amount of 10% by weight, and the composition was then activated in an extensional homogenizer at a pressure of 1500 psi. inch (10342.5 kPa) for two passes. The viscosity of the product at 6 rpm was 214 cP (214 mPa · s).

Each sample exhibited excellent and highly desirable viscosity and yield strength modification results. With respect to bacterial cellulosic products, such results have so far been unattainable, whether it concerns the bacterial cellulosic materials themselves and / or methods for their production of low complexity.

Example 19

1.1 L of lysed MFC broth was mixed with a predetermined amount of xanthan gum and CMC solutions (ratio MFC / xanthan gum / SMS = 6/3/1). This mixture was then precipitated with pure ethanol (99%). The resulting filter cake was dried and crushed on a laboratory bench. After activation using an APV homogenizer at 2500 psi. inch (16.6 MPa) product viscosity (0.3%), determined using a Brookfield viscometer at 60 rpm (spindle 61) in standard tap water, was 91.7 cP (91.7 mPa · s).

Example 20

1 liter of lysed MFC broth was mixed with a predetermined amount of guar gum and solutions, CMC (ratio MFC / guar gum / SMS = 3/1/1). This mixture was then precipitated with pure ethanol (99%). The resulting filter cake was dried and crushed on a laboratory bench. After activation using an APV homogenizer at 2500 psi (16.6 MPa), the viscosity of the product (0.3%), determined using a Brookfield viscometer at 60 rpm (spindle 61) in standard tap water, was 64, 5 cP (64.5 MPa · s).

Although this invention will be described and described in connection with specific preferred embodiments and practical implementations, this invention should in no way be limited to these specific embodiments, but rather are intended to encompass equivalent structures and all alternative embodiments and modifications, as may be determined based on the scope of the attached claims and its equivalent.

Claims (31)

1. A method of obtaining a composition with improved rheological properties containing bacterial cellulose, comprising the steps of:
a) obtaining a bacterial cellulose product by fermentation;
b) possibly lysis of bacterial cells from a bacterial cellulose product;
c) mixing said bacterial cellulose product from step a or step b with a polymer thickener selected from the group consisting of at least one charged cellulose ether, at least one precipitating agent, and any combination thereof; and
g) coprecipitation of the mixture from stage "c" with alcohol. 2. The method according to claim 1, where the specified polymer thickener from stage "in" is a charged cellulose ether. 3. The method according to claim 2, where the specified charged cellulose ether is selected from the group consisting of sodium carboxymethyl cellulose, cationic hydroxyethyl cellulose and any mixtures thereof. 4. The method according to claim 1, where the specified polymer thickener from stage "in" is a precipitating agent. 5. The method according to claim 4, where the specified precipitating agent is selected from the group consisting of xanthan gum, pectin, alginates, gellan gum, velan gum, diutan gum, ramzan gum, carrageenan, guar gum, agar, gum arabic, ghatti gum, gums of karaya, tragacanth gum, tamarind gum, locust bean gum and any mixtures thereof. 6. The method according to claim 1, where the specified bacterial cellulose product is microfibrillar cellulose. 7. The method according to claim 5, where the specified polymer thickener from stage "in" is a charged cellulose ether. 8. The method according to claim 7, where the specified charged cellulose ether is selected from the group consisting of sodium carboxymethyl cellulose, cationic hydroxyethyl cellulose and any mixtures thereof. 9. The method according to claim 5, where the specified polymer thickener from stage "in" is a precipitating agent. 10. The method according to claim 9, wherein said precipitating agent is selected from the group consisting of xanthan gum, pectin, alginates, gellan gum, diutan gum, velan gum, ramzan gum, carrageenan, guar gum, agar, gum arabic, ghatti gum, gums of karaya, tragacanth gum, tamarind gum, locust bean gum and any mixtures thereof. 11. The method according to claim 10, where the specified precipitating agent is selected from the group consisting of xanthan gum, pectin, diutan gum and any mixtures thereof. 12. A method of obtaining a composition with improved rheological properties containing bacterial cellulose, comprising the steps of:
a) obtaining a bacterial cellulose product by fermentation;
b) possibly lysis of bacterial cells from a bacterial cellulose product;
c) mixing said bacterial cellulose product obtained from step a or step b with at least one precipitating agent selected from the group consisting of xanthan gum, pectin, alginates, gellan gum, velan gum, diutan gum, ramzan gum , carrageenan, guar gum, agar, gum arabic, ghatti gum, karaya gum, tragacanth gum, tamarind gum, locust bean gum and any mixtures thereof; and
g) coprecipitation of the mixture from stage "c" with alcohol. 13. The method according to item 12, where the specified precipitating agent is selected from the group consisting of xanthan gum, pectin, diutan gum and any mixtures thereof. 14. A method of obtaining a composition with improved rheological properties containing bacterial cellulose, comprising the steps of:
a) obtaining a bacterial cellulose product by fermentation;
b) mixing said bacterial cellulose product with at least one precipitating agent selected from the group consisting of xanthan gum, pectin, alginates, gellan gum, velan gum, diutan gum, ramzan gum, carrageenan, guar gum, agar, arabian gum, ghatti gum, karaya gum, tragacanth gum, tamarind gum, locust bean gum and any mixtures thereof;
c) joint lysis of the mixture from stage "b" in order to remove bacterial cells from it; and
g) coprecipitation of the mixture from stage "c" with alcohol. 15. The method according to 14, where the specified precipitating agent is selected from the group consisting of xanthan gum, pectin, diutan gum and any mixtures thereof. 16. A composition with improved rheological properties, comprising bacterial cellulose, comprising at least one bacterial cellulosic material and at least one polymer thickener selected from the group consisting of at least one charged cellulose ether, at least one precipitating agent, and any mixtures thereof, wherein said composition has a viscosity characteristic of at least 300 cP (300 mPa · s) and a yield strength of 1.0 dyn / cm ² (0.1 N / m) when placed in an amount of not more than 0.36 wt. .% per sample water volume of 500 ml and after application in an extensional homogenizer at a pressure of 1500 psi. inch (10342.5 kPa) no more than two passes. 17. The composition according to clause 16, where the specified polymer thickener is at least one charged cellulose ether. 18. The composition of claim 17, wherein said charged cellulose ether is selected from the group consisting of at least one sodium carboxymethyl cellulose, at least one cationic hydroxyethyl cellulose, and any mixtures thereof. 19. The composition according to clause 16, where the specified polymer thickener is a precipitating agent. 20. The composition of claim 19, wherein said precipitating agent is selected from the group consisting of xanthan gum, pectin, alginates, gellan gum, velan gum, ramzan gum, carrageenan, guar gum, agar, gum arabic, ghatti gum, karaya gum, tragacanth gum, tamarind gum, locust bean gum and any mixtures thereof. 21. The composition of claim 16, wherein said bacterial cellulosic product is microfibrillar cellulose. 22. The composition according to item 21, which includes both the specified charged cellulose ether and the specified precipitating agent. 23. The composition of claim 22, wherein said precipitating agent is selected from the group consisting of xanthan gum, pectin, alginates, gellan gum, velan gum, diutan gum, ramzan gum, carrageenan, guar gum, agar, gum arabic, ghatti gum, gums of karaya, tragacanth gum, tamarind gum, locust bean gum and any mixtures thereof. 24. The composition of claim 23, wherein said charged cellulose ether is sodium carboxymethyl cellulose. 25. The composition according to paragraph 24, where the specified precipitating agent is selected from the group consisting of xanthan gum, pectin, diutan gum and any mixtures thereof. 26. The composition according A.25, where the specified precipitating agent is xanthan gum. 27. The composition according A.25, where the specified precipitating agent is a pectin. 28. The composition according A.25, where the specified precipitating agent is a diutan gum. 29. The composition of claim 20, wherein said precipitating agent is xanthan. 30. The composition according to claim 20, where the specified precipitating agent is a pectin. 31. The composition according to claim 20, where the specified precipitating agent is a diutan gum.