WO2012004219A1 - Method for producing a fertilizer - Google Patents

Abstract

The invention relates to a fertilizer for plants and to a method for producing said fertilizer. The method according to the invention comprises the following steps: making whey available, anaerobic fermentation of the whey to produce biomass, integration of a base fertilization in accordance with one of the two embodiments of the production method described in the invention and optionally drying to optimize the shelf life of the product and to inactive the yeast.

Description

 Process for the production of a fertilizer

The invention relates to a method for producing a fertilizer for plants. The obtained protein-rich fertilizer based on fermented whey and / or other fermented residues that are produced in the dairy can be used for soil improvement, especially organic farms. Furthermore, it is used as a biofertilizer for individual consumers, such. B. gardeners suitable.

description

 With the present invention, the growing demand for organically grown agricultural products - crops, livestock and horticulture - can be better met. By recycling waste and by-products of plant and animal origin, closed soil cycles are designed to preserve and improve soil fertility and counteract soil erosion, which occurs particularly on lean soils.

Whey is produced during cheese production and consists of about 94% water, about 4% to 5% lactose and is almost fat free. In addition, it contains lactic acid, vitamins Bl, B2 and B6 as well as potassium, calcium, phosphorus and other minerals and 0.6% to 1% whey protein.

There are generally two types of whey: the rennet or sweet whey that is produced when you make milk with cheese making cheese, and the sour whey that comes from treating milk with lactic acid bacteria.

The invention relates to a method for producing a fertilizer for plants. This procedure comprises the following steps:

Pasteurization and storage

 First, whey z. B. obtained as a waste product of cheese production provided.

The term whey as used herein refers to whey permeate, molasses from the dairy industry, and processed molasses are equivalent raw materials such as sweet and / or sour whey. All of these herein as whey addressed products can according to the invention as Starting material for the aerobic fermentation to be used for the production of nitrogen-rich fertilizer.

The whey is treated as needed (eg pasteurized and / or concentrated and / or cold stored). The pasteurization and the cold storage serve to prevent a whey spoil, z. B. by an incipient spontaneous and unwanted lactic acid fermentation. The whey is tempered after the cold storage before fermentation to the desired fermentation temperature. The use of non-pasteurized whey is possible, but carries the risk of infection.

fermentation

 It is not necessary to separate the whey from the fermentation of proteins. Rather, the proteins are processed in the process to maintain them as an additional natural nitrogen source for soil improvement.

In general, yeasts that are used in technology (eg Saccharomyces cerevisiae) are characterized by the ability to organize their metabolism under both anaerobic and aerobic conditions. In anaerobic metabolism, the yeasts produce ethanol. In aerobic metabolism, the production of biomass is the main product of the yeast metabolism. Both processes are used for the Saccharomyces yeasts. The production of baker's yeast and the Hefereinzucht in the brewery are largely carried out aerobically. The production of alcoholic products (such as beer or wine) is anaerobic. The aerobic metabolic pathway is the preferred process of yeasts, but it is limited by factors such as oxygen supply and sugar supply. Oxygen is essential for the aerobic process. The method according to the invention involves an aerobic metabolism of whey. The aerobic fermentation of the whey is preferably carried out by means of a lactose-positive yeast, in particular by using a strain of the yeast genus Kluyveromyces marxianus.

The initiation of the aerobic fermentation for biomass production is carried out by inoculating the whey provided, optionally together with other starting materials, with a lactose-positive yeast, in particular with the yeast Kluyveromyces marxianus. In this case, a yeast culture is first brought to Anstellkonzentration which optimally> 10 ⁸ cells per ml. Subsequently, the whey is inoculated with the yeast introduced and the fermentation is preferably continued to a cell concentration of> 10 ⁸ cells per ml. Thereafter, in one embodiment of the invention, a work-up (cleaning and / or enrichment of the cells) can be connected.

Preferably, a lactose-positive yeast strain, in particular a Kluyveromcesstamm for the aerobic fermentation of whey is used for the method described here. It is known that Kluyveromcyces yeasts as lactose positive yeasts are able to directly ferment the lactose contained in the whey. You will u. a. used for the production of alcohol from lactose sources. When using these yeasts is unnecessary in practice when using z. B. Saccharomyces cerevisiae yeasts conventional prior enzymatic digestion of lactose to glucose and galactose as sources of carbohydrate usable by the microorganisms. Kluyveromyces high performance strains are available in the market. These strains ensure high cell growth rates.

In principle, it is possible to use other lactose-positive yeast strains for the fermentation. Alternative strains are z. B. Kluyveromyces lactis, Candida tropicalis, Saccharomyces lactis, Brettanomyces claussenii. Preference is given to using Kluyveromyces marxianus, which has distinguished itself in cell growth rates, especially in long-term experiments, and has proven to be very good in fermentation behavior.

The whey is fermented under aerobic conditions in the main process of production of the nitrogen-rich biofertilizer, so that the yeast produces biomass and inhibits ethanol formation. In practical experiments, the ethanol content was always below 2 g / 100 g. Therefore, the biodegradation of ethanol or its process removal after the fermentation is not necessary. Due to the drying and inactivation of the biomass formed as described below, the formation of ethanol during biomass production is not a quality-limiting element for the quality of the fertilizer. However, the alcohol formation has a reducing effect on the biomass formed and should therefore be inhibited. The biomass thus produced can be used advantageously as a fertilizer for plants.

Variant 1 for the further processing of the biomass to a nitrogen-rich fertilizer

The biomass produced may preferably be attached to a support material, eg. B. a calcium alginate matrix can be immobilized. The preparation of a calcium alginate matrix is known to the person skilled in the art. It is described for example in DE 68919620 T2 and CA 201240 AI.

According to a preferred embodiment of the invention, a suspension is produced from the yeast biomass or the biomass and sodium malginate which are concentrated after the fermentation. This suspension is dripped into a calcium chloride or calcium carbonate solution (about 2% strength) in a technological process. The forming calcium algiant spheres include the biomass inside. This process is called immobilization of the yeasts in calcium alginate. Additional mineral fertilizer components such. For example, potassium may be admixed to the calcium solution prior to the addition of the yeast sodium alginate suspension as needed and for the production of fertilizers having certain properties.

The produced immobilized yeast biomass is finally dried. This product is characterized by good storage properties and an inactivated yeast. It can be used directly as a plant fertilizer. Mixing with other commercially available fertilizers is possible.

Variant 2 for the further processing of the biomass into a nitrogen-rich fertilizer

In a further preferred embodiment, the biomass produced in the fermentation or the biomass concentrated after the fermentation is mixed directly with mineral fertilizers to form a combined nitrogen and mineral fertilizer, it being possible optionally to carry out a subsequent drying after the mixing.

The drying serves to inactivate the yeast biomass and the production of a storable fertilizer, preferably with a solids content of> 92%, but can be useful. if the dry matter content already exceeds 88% due to the selected blending.

The mixing of the obtained biomass with mineral fertilizers is preferably carried out with minerals such as calcium, potassium, nitrogen and / or phosphate. The composition can be made variable according to the desired fertilizer composition. However, in a preferred embodiment of the invention, calcium as the main component should be present in excess of 80% in the admixture with the biomass.

If the drying is dispensed with due to the high proportion of mineral fertilizer in the mixing ratio between the yeast biomass and the mineral constituents, the yeast biomass is still active. To avoid subsequent alcohol formation (eg in the production of silage), therefore, a sufficient thermal treatment for inactivating the vital yeasts is advantageous; but this is not mandatory.

General

 The positive effect of yeasts on soil quality is detectable. In particular, when using the immobilized yeasts, the dissolution in the soil after the introduction is carried out only gradually, so that a long-term effect can be achieved. The long-term effect is based on the effect that the support material, in particular the calcium alginate coat in the soil only gradually absorbs moisture. As a result, availability of the fertilizer is achieved over a longer period of time, prevents washing out into deeper soil layers and the upper soil layers can be improved in a sustainable way.

The strain Kluyveromyces marxianus to be used preferably in the aerobic fermentation is known to the person skilled in the art. B. isolated from yoghurt. The yeast can be purchased as a pure yeast.

The biomass produced is after the fermentation in a carrier material, preferably in a calcium alginate matrix, integrated (immobilized). By embedding the biomass in a carrier material, for example, the described calcium alginate coat a good introduction into the soil is possible. Alginates are based on alginic acid, which can be obtained from marine brown algae. Alginates are available for purchase.

The fertilizer has good fertilizer and storage properties. In addition to the nitrogen fertilizer derived from the biomass, it also contains calcium, which is recognized as a basic fertilizer. In one embodiment of the invention, in addition to calcium and sodium alginate, potassium may be incorporated during immobilization to yield a fertilizer rich in calcium as well as in potassium. Other minerals such as phosphates or additional nitrogen can be added to the fertilizer.

Thus, in one embodiment, the fertilizer produced according to the invention is a nitrogen-rich fertilizer with integrated basic fertilizer (calcium and additionally potassium).

For the immobilized yeast in its use as a biofertilizer are washout effects, the z. As the use of immobilized yeasts in the beverage industry often difficult to expressly desired for use as a fertilizer. The preferably used calcium gel dressing (calcium alginate matrix) not only serves as a desired stable carrier, it imparts in the resulting fertilizer an additional own fertilizing effect (basic fertilization) by the calcium contained.

The fertilizer produced by the process is a nitrogen-rich natural or bio-fertilizer with integrated calcium, which optionally can also be rich in potassium (in particular if additional potassium has been added during immobilization). The fertilizer is rich in proteins. Nitrogen (N), calcium (Ca) and potassium (K) are therefore the most important fertilizers. The protein content of the fertilizer is about 45% to 60% in the dry matter, preferably 45% to 54%.

In the context of the invention, whey, which is due to the rich ingredients as a resulting in the milk processing residue with high processing potential, fed to a complex recycling. This is particularly interesting in that the whey accumulates continuously over the whole year, but the soil fertilization occurs only at certain times. Therefore, the whey-based biofertilizer, which is produced continuously in parallel with the accumulation of whey, must also be storable so that it can be used in accordance with the fertilizer application periods can be used. This is the case with the fertilizer according to the invention. The (bio) fertilizer contributes to the increase of soil fertility and thus to the extension and intensification of organic / ecological producing agricultural and horticultural farms.

In a further aspect, the invention relates to a fertilizer for plants, which can be produced by a method described herein. Such a fertilizer has in particular proteins, calcium and possibly potassium. In particular, the fertilizer according to the invention can serve for the soil improvement of nutrient-poor soils in biological animal husbandry.

In another aspect, the invention relates to the use of a fertilizer for fertilizing plants as described herein. The fertilizer is applied to the soil to be fertilized or mixed with it.

The fertilizer of the invention also serves to improve the water and nutrient storage capacity of permeable soils.

Instead of producing the fertilizer which is immobilized in alginate, in another application it is possible to mix the biomass produced directly with calcium carbonate and other mineral fertilizer constituents and then optionally to dry it.

characters

FIG. 1: Procedure for the production of the fertilizer described here.

The fermentation of whey, (fresh and / or acid whey, whey permeate, molasses from the dairy industry and processed molasses, or alternatively, some of these residues separately or in every possible mixture) is shown in the center. To the whey (with the respective colonies) is added a yeast which is fed under conditions which allow an aerobic fermentation of the whey or the other starting materials. The aerobic fermentation the whey leads to the production of biomass, which can be dried to obtain a fertilizer.

Optional features of the production process or the fertilizer are also shown in FIG. Thus, possible types of pretreatment or storage of the starting materials are shown, such as high-speed flash heating, cold storage up to fermentation with temperature control to fermentation temperature.

Immobilization of the biomass obtained by the fermentation may be accomplished by means of a carrier material, such as sodium alginate, optionally together with the addition of minerals to increase the mineral content of the fertilizer. As minerals calcium and potassium, but also phosphorus and nitrogen can be added as suitable compounds, which can also be immobilized.

The biomass, possibly with additional added minerals, can be mixed with mineral fertilizer before drying. Thus, the fertilizer can be adjusted by its nutrient content to the respective requirements.

example

Theoretical considerations

The lactose content of a whey is about 5.21 g / 100 g (52.1 g / kg). From 100 g of monosaccharide and 40 g of 0 ₂ formed in the aerobic fermentation about 54 g of yeast dry matter and carbon dioxide and water.

Based on a farm producing 8,000 1 / week whey, 416.8 kg of lactose are produced weekly. This corresponds to a biomass dry matter production of 225 kg per week (11.7 t per year).

The proportion of crude protein in the yeast dry matter is 45% to 60%. About 20% of these are water-soluble polypeptides and amino acids.

The mentioned protein content corresponds to a soil fertilization of 23.4 to 70.2 ha, depending on the soil quality. This basic fertilising effect can be enhanced by the calcium used in the optional immobilization (about 2% solution) and the optional addition of potassium. The yeast itself has a proportion of minerals (Ρ ₂ 0 ₅ and K ₂ 0) and thus also contributes a basic fertilization effect.

Process Level 1 "Hefereinzucht and Herführung"

 A - Cultivation of a lactose-positive yeast strain

 • z. B. Kluyveromyces marx. CBS 397/6432

 • Inoculate into 50 ml of YPL nutrient solution

 • Incubation for 24 - 25 h

 • Temperature 30 - 35 ° C

 • Continuous ventilation

• Cell concentration approx. 70 - 90 * 10 ⁷ cells / ml

B - Deriving the yeast strain (1st stage of production)

 • 400 ml of whey / permeate + 50 ml of yeast suspension

• Inclination concentration: approx. 70 - 80 * 10 ⁶ cells / ml • Continuous ventilation or controlled impulse ventilation

C - Stepwise reduction / recovery

Herführung (preferably in a mixing ratio of 1 part yeast substrate + 9 to 10 parts of sterile whey or whey permeate) to the Anstellkonzentration with aeration, at about 20 ° C for 18 to 24 hours per Herführstufe. Cell concentration should be 3 to 5 * 10 ⁸ CFU (nucleating units) per ml at the end of each stage of the preparation.

Process step 2 "fermentation"

 (Example small scale about 40 to 50 liters)

 Process control: Various types of process management are possible, such as the batch process, drainage process, semi-continuous process, continuous process or feed process.

Description of the drainage process as a possible fermentation variant

4.5 1 yeast substrate are made with 45 1 whey and fermented at about 25 ° C. Instead of whey, whey permeate, molasses or processed (diluted) molasses can also be used.

 The fermentation lasts a maximum of 24 h. After this time, 40% to 80% of the fermentation medium is harvested, which are further processed into fertilizer. To the remaining substrate remaining in the fermenter new whey or whey permeate or molasses can be left on it. The fermentation can be maintained over several months. Only occasionally a refreshment with newly introduced yeast is necessary.

The substrates should be pasteurized accordingly before use via a Hochkurzeitverfahren (see also Figure 1). To avoid substrate bottlenecks, the inclusion of an intermediate storage after pasteurization is recommended. When using exclusively fresh sweet whey but also a direct use of the substrate without prior pasteurization has proven.

Process step 3a "Blending with basic fertilizer constituents and drying" The biomass produced from whey substrate is mixed in a conventional mixer with mineral fertilizer components, preferably calcium carbonate. The mixing ratio of the desired ratio of biomass (nitrogen fertilizer) to basic fertilizer can be varied. It is preferred that the dry matter content before drying is already above 60% and so the costly drying can be reduced. To increase the nitrogen output, it is possible to concentrate the biomass before mixing. Suitable for this purpose are customary separators and filter systems. Alternatively, there is the possibility of settling the biomass in an optimally cooled to 0 to 2 ° C fermentation system.

The downstream drying serves to inactivate the yeast biomass and to produce a storable fertilizer with a solids content of> 92%.

Process Stage 3b "Immobilization and Downstream Drying"

 In a preferred embodiment, the method comprises the step of immobilizing the biomass produced from whey in a carrier material, in particular in a calcium alginate gel dressing. The preparation of immobilized dry biomass results in a product in which the yeast biomass is immobilized in the basal fertilizer unit. This preferred embodiment of the process is somewhat more complicated than the variant described under 3 a, but leads to a fertilizer that does not dissolve so quickly in aqueous solutions, thus ensuring a longer soil availability.

A practice-typical immobilization variant is described below: A mixture is produced from the fermented biomass and a sodium alginate solution. This mixture is passed through at least one cannula in an approximately 2% calcium chloride solution. An integrated air flow at the exit of the cannulas leads to the tearing off of individual drops, which drips into the calcium chloride solution. The incorporation of calcium into the sodium alginate yeast compound produces jelly-like whitish spheres. These are separated after separation from the Restcalciumchloridlösung, dried and can be packaged in appropriate shipping packages. The drying serves to inactivate the yeast and to produce a durable, storable product.

Claims

claims A process for preparing a fertilizer for plants, comprising the following steps:  - provision of whey,  Adding a yeast to the whey for aerobic fermentation,  - aerobic fermentation of whey for the production of biomass as fertilizer. 2. The method of claim 1, comprising the step of  - Drying of the produced biomass. 3. The method of claim 1 or 2, wherein the yeast is a lactose positive yeast, in particular a yeast, which is selected from the group consisting of Kluyveromyces marxianus, Kluyveromyces lactis, Candida tropicalis, Saccharomyces lactis and Brettanomyces clausse- nii. 4. The method of claim 3, wherein the lactose positive yeast is selected from the group consisting of Kluyveromyces marxianus, Kluyveromyces lactis, Candida tropicalis, Saccharomyces lactis and Brettanomyces claussenii. 5. The method of claim 1 to 4, comprising the step of  Immobilization of the biomass produced from whey in a carrier material, in particular in a calcium alginate gel dressing. 6. The method of claim 5, wherein the drying of the immobilized biomass serves to produce a storable product and to inactivate the yeast. 7. The method according to claim 1 to 6, wherein the immobilization of the biomass takes place with the addition of potassium. 8. The method of claim 1 to 7, comprising the step of adding an additive or a trace element for promoting fermentation, wherein as an additive amino acids and vitamins and as trace elements zinc and magnesium are preferred. 9. The method of claim 1 to 8, comprising a mixing of the produced biomass directly with calcium. 10. Fertilizers for plants, producible by a process according to claim 1 to 9. 11. Fertilizer according to claim 10, comprising protein, calcium and potassium. 12. Use of a fertilizer according to claim 10 or 11 for the fertilization of plants.