A high-pressure processing based method for production of an organic fertilizer

Abstract

The present invention relates to a method for the production of an organic fertilizer for plants, more specifically a high-pressure processing (HPP) based method using a fermentation broth. The present invention furthermore relates to an organic fertilizer for plant bio stimulation, wherein the organic fertilizer comprises pelleted lysed microbes and active compounds derived from organic waste, and the use of the organic fertilizer for plants in agriculture, for biostimulation of the plants, including improved plant growth and / or crop yield, more complete plant nutrition, improved plant stress and / or disease resistance.

Description

[0001] A HIGH-PRESSURE PROCESSING BASED METHOD FOR PRODUCTION OF AN ORGANIC FERTILIZER

[0002] Description

[0003] The present invention relates to a method for the production of an organic fertilizer for plants, more specifically a high-pressure processing (HPP) based method using a fermentation broth. The present invention furthermore relates to an organic fertilizer for plant bio stimulation, wherein the organic fertilizer comprises pelleted lysed microbes and active compounds derived from organic waste, and the use of the organic fertilizer for plants in agriculture, for biostimulation of the plants, including improved plant growth and / or crop yield, more complete plant nutrition, improved plant stress and / or disease resistance.

[0004] Global crop production has increased in recent decades to meet the requirement of the rapidly growing amount of food consumed globally. Addition of synthetic nitrogen fertilizers resulted in reliable agricultural crop productivity with healthy and strong plants as the application of those fertilizers significantly increase the productivity in crops and are critical to reach high yields each year. However, using artificial fertilizers comprising nitrogen has a damaging effect on the environment and producing these fertilizers is energy intensive. Therefore, natural plant protection products and plant growth enhancers are currently the preferred approach and continuously being developed.

[0005] A natural way to add nutrients to the soil is via composting. Compost is obtained by soil bacteria and fungi that decompose dead material within the soil, which contributes to the improvement of physical, chemical, and microbiological properties of the soil. Compost comprises digested and fermented biomass serving as nutrients for plants. Although compost is a means to break down waste and circularize the food chain, it is not ideal for fertilizer in agriculture because compost production is a slow process ready for use. Also, compost does not retain the compounds very well. In general, the older the compost, the fewer nutrients it offers since these nutrients will leach out over time.

[0006] Although compost contains little compounds compared to synthetic fertilizers, the microbes and their metabolites within the compost themselves are targeted by industry to obtain biological fertilizers with living microbes that are very potent, interact with plants and improve the productivity of plants like artificial fertilizers. However, the microbes within the biological fertilizer are live microbes and require the right storing conditions to maintain viability and to extend their limited shelf life. Moreover, the functionality of the microbe is dependent on its environment, therefore, using living microbes within a fertilizer requires knowledge about what type of microbe is effective in what condition, crop type, climate and / or soil as. Furthermore, living microbes may be unpredictable in how they interact with the local ecosystem as the rhizospheres and dependent on other factors. Living fertilizers are sensitive. As such, residues of previous chemicals in bulk tanks and applicators or contamination with unwanted microbes may kill microbes. Moreover, in order to use microbes within fertilizers it mandates verification by the government in that their use is safe. Before microbes are allowed to be used, multiple qualification steps are required to ensure that it will not affect other non-target organisms.

[0007] In the procedure for obtainment of organic fertilizers for agriculture, biological waste is preferably used for assets like waste processing and circularization of the food chain. Waste can be fermented into a broth that comprises nutrients which are ready for use by the plant. To have the optimal products derived from microbes within the broth and overcome drawbacks such as contamination by detrimental organisms within the fertilizer, the organic waste is often sterilized. Sterilization of large quantities of broth, however, is cumbersome, costs high energy and requires pricey autoclaves. Moreover, sterilization may have a negative effect on the efficacy of produced metabolites as some compounds may even decompose around 60 °C.

[0008] Therefore, there remains a need for a new eco-friendly production method for the fast production of a safe and easy-to-use organic fertilizer that improves a plants’ growth, its health and development, while reducing the use of synthetic nitrogen. Considering the above, there is a need in the art to provide for a fast producible natural fertilizer with natural compounds and secondary metabolites derived from microbes that are ready for absorption by the plant and that is all-round applicable.

[0009] It is an object of the present invention, amongst other objects, to address the above need in the art. The object of present invention, amongst other objects, is met by the present invention as outlined in the appended claims.

[0010] Specifically, the above object, amongst other objects, is met, according to a first aspect, relating to a method for the production of an organic fertilizer for plants, wherein the method comprises the steps of a) providing a starting broth comprised of;

[0011] - between 5 to 45 g / L, preferably between 10 to 30 g / L, more preferably 15 to 20 g / L of a nitrogen source, preferably hydrolyzed casein, and / or hydrolyzed soybean protein.

[0012] - between 10 to 100 g / L, preferably between 25 to 75 g / L, more preferably between 30 to 60 g / L of a carbon source, preferably a solution comprising sugar and / or alcohol, such as a yeast extract, more preferably a glucose, sucrose, glycerol, mannitol, or polysaccharides.

[0013] - between 0.001 to 5 g / L, preferably between 0.05 to 2 g / L, more preferably between 0.1 to 1 g / L of a mineral salt, preferably potassium phosphate, potassium sulphate, iron salts, calcium salts or manganese / molybdenum salts, more preferably ferrous sulphate; - between 0.0001 and 0.5 g / L, preferably between 0.005 and 0.1 g / L, more preferably between 0.001 to 0.01 g / L of a catalyst selected from the group consisting of ferrous sulphate, cobalt sulphate, ammonium nitrogen, or other suitable catalyst salts b) adding Lactic Acid Bacteria (LABs) and / or Plant Growth Promoting Microorganisms (PGPMs) to the starting broth to initiate fermentation and to provide a fermentation broth c) pelleting of the fermentation broth to obtain a pellet and a supernatant d) subjecting the pellet to high-pressure processing (HPP) thereby providing the organic fertilizer for plants.

[0014] The method for the production of an organic fertilizer is an environmentally friendly method providing an organic fertilizer that comprises biologically produced compounds originating from a fermentation broth, more specifically the cells and its content from the cultivated LABs and / or PGPMs, which promote plant growth by increasing the supply or availability of nutrients to the host plant. This bio stimulation of the plant results in improved growth, complete nutrition, disease resistance, and fruit production.

[0015] The first step a) of the method is to provide a starting broth comprising amino acids, sugars, mineral salts, (degraded) proteins such as degraded casein, degraded soybean, degraded corn. Preferably the nitrogen is a protein source, more preferably a hydrolyzed protein source, such as hydrolyzed casein or soybean protein. Vitamins give nutrition for microbial fermentation and growth. The starting broth thus comprises a nitrogen or protein source (usually yeast extract, soy extract, peptones, or free amino acids), a carbon source (such as sugars or glycerol, mannitol, and polysaccharides), mineral salts (such as potassium phosphate, potassium sulphate, iron salts, calcium salts and manganese / molybdenum salts). Furthermore, preferably organic matter may used as nitrogen and carbon sources and can include any organic matter which can be broken down into carbon dioxide, peptides, free amino acids, water, methane, compost, humus, and simple organic molecules by micro-organisms and other living things by composting, aerobic digestion, anaerobic digestion or similar processes.

[0016] The next step, step b), is adding LABs and / or PGPMs to the starting broth to initiate fermentation and to provide a fermentation broth. Preferably, about 105to 109cfu / ml of LAB and / or PGPMs are in total added to the starting broth. This broth is incubated at parameters depending on the microbes that are inoculated, usually at a temperature between 28° to 42°C, preferably 30 to 38°C, an incubation time of between 8 to 40 hours, preferably 12 to 36 hours, more preferably 18 to 24 hours, and a pH of between 5.5 and 7.5. The broth is preferably kept in agitation of between + 1 and 2 m / s.

[0017] In step c) the fermentation broth is pelleted, thereby separating the microbes from the supernatant. Any suitable separation technique may be used for pelleting the fermentation broth. For example, centrifuging the broth at a speed between 6000 to 7500 rpm for 30 min, or by filtering the broth using size exclusion filters.

[0018] In step d) is the pellet subjected to HPP to provide an organic fertilizer for plants. Only the pellet is subjected to HPP. HPP is a technique widely used in the food industry for preservation of food by high pressure without additives or heat. This HPP procedure allows for inactivation of microbes without the damaging effect of heat (used in the art) upon the produced metabolites and other compounds which then remain intact and active in the fertilizer being produced. Moreover, the sterilization of only the pellet leads to a much more consistent level of sterilization of the broth compared to sterilization of the whole fermentation broth. Sterilization of the pellet allows for full control over the broth as removal of activated microbes stops unwanted development during transportation and selling, whilst comprising secondary metabolites of said microbes. Preferably, the final organic fertilizer solution comprises active compounds produced by the microbes such as organic acids (such as lactic acid, succinic acid, citric acid, malic acids, fumaric acids, phenyl-lactic acid, and including volatile organic compounds (such as 2hydroxy-4- (methilthio)butanoic acid, 2-hydroxyvaleric acid, benzoic acid, diacetyl, butanoic acid, octanoic acid), plant hormones (auxin, cytokinins, giberellic acid, ethylene).), enzymes (such as phytase, ferulic acid esterase, protease, cellulase, lipase), free sugars (such as inositol).

[0019] According to a further embodiment, the present invention relates to the method for the production of an organic fertilizer for plants, wherein wherein the LABs is one or more selected from the group consisting of Lactoplantibacillus, Lactobacillus, Lactobacillus paracasei, Lactococcus, Leuconostoc, Bifidobacterium genus, Brevibacterium genus, Streptococcus, preferably Lactobacillus paracasei.

[0020] According to a further embodiment, the present invention relates to the method for the production of an organic fertilizer for plants, wherein PGPM is one or more selected from the group consisting of Azospirillum, Azotobacter, Rhizobium, Bradyrhizobium, Sinorhizobium, Ensifer, Pseudomonas, Bacillus, Burkholderia, Gluconacetobacter, Gluconobacter, Acetobacter, Variovorax, Streptomyces, Paraburkholderia, Acinetobacter, Arthrobacter, Paenibacillus, Chriseobacter, Lysobacter, Saccharomyces, Colletotrichum, Beauveria, Trichodermd), preferably Azospirillum genus. The PGPMs are selected for their ability to grow, survive and multiply on plant organs, and to promote beneficial activities on plant growth, nutrition and defense, with their combinations of enzymes and secondary metabolites, which can create a variegate portfolio of new low-cost, and high-efficacy products.

[0021] According to yet another embodiment, the present invention relates to the method for the production of an organic fertilizer for plants, wherein the HPP is performed at a pressure of between 4500 to 8000 bar, preferably 5000 to 7000 bar, more preferably 5500 to 6500 bar. When the HPP is performed at pressure lower than 4500 bar the cold pasteurization is not performed optimally leading to a suboptimal (or even unusable) product, since the microbes may be active. Performing HPP above 6500 bar, the beneficial effect of a cost effective and energy low method will decline drastically.

[0022] According to a preferred embodiment the present invention relates to the method for the production of an organic fertilizer for plants, wherein the HPP is performed at a temperature of between 0 to 20°C, preferably between 2 to 10°C, most preferably between 3 to 8°C. Performing HPP outside the lower recited temperature range, the cold pasteurization is not performed optimally leading to a suboptimal (or even unusable) product, since the microbes may be active. Above the recites temperature, also here the energy consumption of the method will increase drastically. Furthermore, higher temperatures will also affect the protein and enzymes present in the fertilizer being produced, thus negatively affecting the resulting fertilizer product by damaging, denaturing or degrading these compounds resulting in less or even inactive compounds.

[0023] According to a further embodiment, the present invention relates to the method for the production of an organic fertilizer for plants, wherein the HPP is performed for at most 15 minutes, preferably at most 10 minutes, more preferably at most 5 minutes.

[0024] According to a further embodiment, the present invention relates to the method for the production of an organic fertilizer for plants, wherein fermentation and to provide a fermentation broth is performed at temperature of between 28° to 42°C, preferably 30 to 38°C, an incubation time of between 8 to 40 hours, preferably 12 to 36 hours, more preferably 18 to 24 hours, and a pH of between 5.5 and 7.5, preferably 6 to 7.

[0025] According to a further embodiment, the present invention relates to the method for the production of an organic fertilizer for plants, wherein the method further comprises the step of mixing the pellet before being subjected to HPP with the supernatant of step c). The pellet is mixed with part of the supernatant to improve the manageability and homogenization of the organic fertilizer in a solution and to more easily standardize the volumes and the productions of the organic fertilizer, ensuring a consistent product.

[0026] According to a preferred embodiment the present invention relates to the method for the production of an organic fertilizer for plants, wherein the fermentation broth of step b) is subjected to a further processing step selected from the group consisting of buffering, aeration, and agitation for increased production or yield of plant bio stimulant metabolites. Further processing of the broth will increase the production or yield of plant bio stimulant metabolites from the LABs and / or PGPBs which will eventually be comprised in the organic fertilizer being produced.

[0027] The present invention, according to a further aspect, relates to an organic fertilizer for plant bio stimulation, wherein the organic fertilizer comprises pelleted lysed lactic acid bacteria (LABs) and / or and / or Plant Growth Promoting Microorganisms (PGPMs) comprising bio-active compounds, wherein said bio-active compounds comprise; at least 12 wt%, preferably at least 15 wt%, more preferably at least 17 wt% lactic acids and organic acids, wherein the organic acid is one or more selected from the group consisting of lactic acid, succinic acid, citric acid, malic acids, fumaric acids, phenyl-lactic acid, and preferably also include between 0,02 to 0,15 wt%, preferably 0,03 to 0,1 wt% of volatile organic compounds, wherein the volatile organic compounds is one more selected from the group consisting of 2hydroxy-4- (methilthio)butanoic acid, 2-hydroxyvaleric acid, benzoic acid, diacetyl, butanoic acid, octanoic acid; at most 3 wt%, preferably at most 2 wt%, more preferably at most 1 wt% alcohol, wherein the alcohol is one or more selected from ethanol, polyphenol and ethyl alcohol; at least 15 wt%, preferably at least 18 wt%, more preferably at least 20 wt% of one or more enzymes enzymes, wherein the enzyme is one or more selected from the group consisting of phytase, ferulic acid esterase, protease, cellulase, lipase; at least 0,5 wt% sugars, preferably 0,8 wt%, more preferably 1 wt% sugars, wherein sugars are preferably free sugars and / or polysaccharides, preferably inositol;

[0028] 5 to 25 wt% preferably 10 to 20 wt% fatty acids, and 0,002 to 0,18 wt%, preferably 0,008 to 0,12, more preferably 0,01 to 0,1 wt% plant hormones, wherein plant hormones is one or more selected from the group consisting of auxin, cytokinins, giberellic acid and ethylene plant hormones; based on the total dry weight of the organic fertilizer.

[0029] The organic fertilizer is an environmentally friendly source of plant nutrients that promote growth by increasing the supply or availability of nutrients to the host plant, and it stimulates the plant by activating the growth mechanisms of plants, as well as plant defense mechanisms. The organic fertilizer for plant bio stimulation improves growth, disease resistance, and fruit production. Experiments show that organic fertilizer of the present invention comprising said bioactive compounds provides direct nourishment to the plant, as they can be taken up by the plant tissue and used as direct nutrition. The organic fertilizer stimulates the activation of growth mechanisms within the plants and the defense activation within the plants, stimulates flower development and fruit formation. Furthermore, the organic fertilizer increases the biodiversity of the microbial composition within the soil. This is because the metabolites and compounds are microbially produced, and not synthetic, thus acting through naturally occurring molecules, that guarantee the balance of natural ecosystems. The efficacy of the organic fertilizer is at least comparable, even slightly outperforming the conventional (synthetic) NPK fertilizers, yet is producing the biostimulator effect. According to another embodiment, the present invention relates to the organic fertilizer for plant bio stimulation, wherein the pelleted lysed LABs is one or more selected from the group consisting of Lactoplantibacillus, Lactobacillus, Lactobacillus paracasei, Lactococcus, Leuconostoc, Bifidobacterium, Brevibacterium, Streptococcus, preferably Lactobacillus paracasei.

[0030] According to a preferred embodiment the present invention relates to the organic fertilizer for plant bio stimulation, wherein wherein the pelleted lysed PGPMs is one or more selected from the group consisting of Azospirillum, Azotobacter, Rhizobium, Bradyrhizobium, Sinorhizobium, Ensifer, Pseudomonas, Bacillus, Burkholderia, Gluconacetobacter, Gluconobacter, Acetobacter, Variovorax, Streptomyces, Paraburkholderia, Acinetobacter, Arthrobacter, Paenibacillus, Chriseobacter, Lysobacter, Saccharomyces, Colletotrichum, Beauveria and Trichoderma, preferably Azospirillum.

[0031] According to another preferred embodiment the present invention relates to the organic fertilizer for plant bio stimulation, wherein the organic fertilizer is obtained according to the first aspect of this invention.

[0032] According to yet another embodiment, the present invention relates to the organic fertilizer for plant bio stimulation, wherein the organic fertilizer is a liquid organic fertilizer. Preferably the pelleted LABs and / or PGPMs that comprise the bioactive compounds are dissolved in an acqeous solution or the supernatant obtained from the production process of the organic fertilizer.

[0033] According to another preferred embodiment the present invention relates to the organic fertilizer for plant bio stimulation, wherein said plant bio stimulation is of a plant preferably a horticultural crop, more preferably a horticultural crop selected from a lettuce or a tomato plant. The organic fertilizer of present invention in especially well suitable for use in horticulture.

[0034] The present invention, according to a further aspect, relates to a use of an organic fertilizer, for plant bio stimulation. Plant bio stimulation comprises the improvement of plant growth, immunity, improved stress tolerance or resistance, and increased fruit yield.

[0035] According to a preferred embodiment, the present relates to the use, wherein 100 to 6000g, preferably 300 to 5500g, most preferably 500 to 5000 g of said organic fertilizer is dissolved in 200 to 500 L, preferably in 300 to 400 L of aqueous solution, preferably in water, per 1 hectare of soil receiving said organic fertilizer. The organic fertilizer may be a concentrated product which can be dissolved in water for use. Application of the organic fertilizer comprises through irrigation water, directly to the soil or foliar spraying of the organic fertilizer.

[0036] According to a further embodiment, the present relates to the use wherein the organic fertilizer is added to a plant, preferably to the soil of said plant, at sowing, plant germination, plant sprouting or plant transplantation, plant growth phase or plant reproduction, preferably at plant sprouting or plant transplantation. According to another preferred embodiment, the present invention relates to the use, wherein said plant bio stimulation is of a plant preferably a horticultural crop, more preferably a horticultural crop selected from a lettuce or a tomato plant. The use of the organic fertilizer providing bio stimulation is especially suited for use in horticulture applications.

[0037] The present invention will be further detailed in the following examples and figures wherein:

[0038] Figure 1: Shows the distribution of the above-ground plant shoot diameters in cm2of the lettuce plants treated with the fertilizer composition of present invention comprising cell pellet of pascalized Lactobacillus paracasei as organic fertilizer (right) and control plants treated with a conventional NPK fertilizer (left), after an application of 1 kg / ha. The error bars represent sample distribution, the horizontal line represents average value, and the box size the standard deviation. Each dot is a single plant query.

[0039] Figure 2: Shows the distribution of the apical biomass in gram (g) of the lettuce plants treated with the fertilizer composition of present invention (right) and control (left) plants treated with a conventional NPK fertilizer, after an application of 1 kg / ha.

[0040] Figure 3: Shows the distribution of the root biomass in gram (g) of the lettuce plants treated with the fertilizer composition of present invention (right) and control (left) plants treated with a conventional NPK fertilizer, after an application of 1 kg / ha.

[0041] Figure 4: Shows the distribution of the plant biomass in gram (g) of the tomato plants treated with the fertilizer composition of present invention (right) and control (left) plants treated with a conventional NPK fertilizer, after an application of 1 kg / ha.

[0042] Figure 5: Shows the distribution of the number of fruits per plant of the tomato plants treated with the fertilizer composition of present invention (right) and control (left) plants treated with a conventional NPK fertilizer, after an application of 1 kg / ha.

[0043] Figure 6: Shows the distribution of the leaf surface (in cm2) of the tomato plants treated with the fertilizer composition of present invention (right) and control (left) plants treated with a conventional NPK fertilizer, after an application of 1 kg / ha. Examples

[0044] Example 1: _ Production of fertilizer composition from the fermentation broth by HPP

[0045] The fertilizer composition of present invention is produced according to the method below. Briefly, a starting broth is prepared by mixing a yeast extract 10 g / L, casein peptone 10 g / L, sodium chloride 2 g / L, dipotassium phosphate 0,5 g / L, and iron sulphate 0,01 g / L in water 300 L. Next the starting broth in inoculated with 10 L of a Lactobacillus paracasei active cell suspension (108cfu / ml). Then the fermentation process is initiated for about 8 to 12 hours at 38 to 40 C to produce the metabolic compounds from the LABs, using standard fermentation conditions. Fermentation parameters are: pH 5.5, air flux 8 1pm, agitation 100 to 200 rpm.

[0046] After the fermentation was done, the fermentation broth is collected and used for centrifugation, 6000 rpm x 15 min, to obtain a pellet and a supernatant fraction. The supernatant is removed and the pellet is subsequently treated by HPP, at 6000 bar for 5 min, at 5°C to obtain the organic fertilizer composition that can be used for the bio stimulation of plants.

[0047] This protocol is applicable potentially to any bacteria, which are able to provide nutrients and useful enzymes to the plant and the soil. In this context the PGPMs are an ideal fit, as they are evolved within the soil and plant surface, providing natural source of nutrients. Preliminary screening with PGPMs had shown good compatibility with both the fermentation as well as the HPP protocols. Similarly, the application of their pascalized pellets had indicated positive plant biostimulation (data not shown).

[0048] Example 2: Effect of fertilizer present invention compared to effect synthetic fertilizer

[0049] The organic fertilizer composition of Example 1 was tested in tomato and lettuce in view of its biostimulator effect, in comparison to a conventional liquid N (nitrogen)-P(phosphate)- K(potassium) fertilizer for lettuce and tomato, (1-1-2 for tomatoes and 20-20-20 for lettuce) was applied with recommended application dose following common practices for horticultural crops, and used as the base and reference of agronomical synthetic fertilization. Both products applied in fertigation.

[0050] The N-P-K fertilizers were applied at their recommended dose, while the HPP-derived biostimulant was applied at a dose of 1 kg / ha. Both, tests and controls, were applied in fertigation to lettuce plants grown in greenhouse and applied during transplantation of the plants within the soil. The results show that the fertilizer was able to increase the diameter of the treated lettuce plants, their whole apical biomass, as well as the root biomass (Figure 1 to 3, respectively). Measurements are performed using basic simple harvest measurement methods, measuring the diameter using a ruler and determine biomass weight using a scale. Plants that received treatment with the conventional fertilizer are on the left, plants that received treatment with the organic fertilizer composition of present invention are on the right.

[0051] Similarly, the same fertilizers and dosages were applied to field-grown tomato plants, compared to control plants treated with conventional fertilizer N-P-K. Figures 4 to 6 summarize the results and show that the tomato plant treated with the fertilizer composition of present invention produced more fruit per plants, providing bigger harvests (increased biomass) and the plants had a wider leaf surface. Fruit number was determined by simple counting. Leaf surface area was determined by taking for each plant its fifth (in order of appearance) leaf produced, take its scan copy, and outlining its perimeter. Then the leaf surface area was calculated using Image J software.

Claims

Claims1. Method for the production of an organic fertilizer for plants, wherein the method comprises the steps of a) providing a starting broth comprised of;- between 5 to 45 g / L of a nitrogen source, preferably hydrolyzed casein, and / or hydrolyzed soybean protein;- between 10 to 100 g / L of a carbon source, preferably a source coumprising a sugar and / or alcohol, more preferably a yeast extract;- between 0.001 to 5 g / L g of a mineral salt, preferably a potassium salt such as potassium phosphate;- between 0.0001 and 0.5 g / L of a catalyst selected from the group consisting of ferrous sulphate, cobalt sulphate, ammonium nitrogen, or other suitable catalyst salts, preferably ferrous sulphate; b) adding Lactic Acid Bacteria (LABs) and / or Plant Growth Promoting Microorganisms (PGPMs) to the starting broth to initiate fermentation and to provide a fermentation broth, c) pelleting of the fermentation broth to obtain a pellet and a supernatant, d) subjecting the pellet to high-pressure processing (HPP) providing the organic fertilizer for plants.

2. The method according to claim 1, wherein the LABs is one or more selected from the group consisting of Lactoplantibacillus, Lactobacillus, Lactobacillus paracasei, Lactococcus, Leuconostoc, Bifidobacterium genus, Brevibacterium genus, Streptococcus, preferably Lactobacillus paracasei.

3. The method according to claims 1 or 2, wherein the PGPMs is one or more selected from the group consisting of Azospirillum, Azotobacter, Rhizobium, Bradyrhizobium, Sinorhizobium, Ensifer, Pseudomonas, Bacillus, Burkholderia, Gluconacetobacter, Gluconobacter, Acetobacter, Variovorax, Streptomyces, Paraburkholderia, Acinetobacter, Arthrobacter, Paenibacillus, Chriseobacter, Lysobacter, Saccharomyces, Colletotrichum, Beauveria, Trichoderma.

4. The method according to any one of the claims 1 to 3, wherein the HPP is performed at a pressure of between 4500 to 8000 bar, preferably 5000 to 7000 bar, most preferably 5500 to 6500 bar.

5. The method according to any one of the claims 1 to 4, wherein the HPP is performed at a temperature of between 0 to 20°C, preferably between 2 to 10°C, most preferably between 3 to 8°C.

6. The method according to any one of the claims 1 to 5, wherein the HPP is performed for at most 15 minutes, preferably at most 10 minutes, more preferably at most 5 minutes.

7. The method according to any one of the claims 1 to 6, wherein the method further comprises the step of mixing the pellet before being subjected to HPP with the supernatant of step c).

8. The method according to any one of the claims 1 to 7, wherein fermentation and to provide a fermentation broth is performed at temperature of 28° to 42°C for 8 to 40 hours, and a pH of between 5.5 and 7.5.

9. The method according to any one of the claims 1 to 8, wherein the fermentation broth of step b) is subjected to a further processing step selected from the group consisting of buffering, aeration, and agitation for increased production or yield of plant bio stimulant metabolites.

10. An organic fertilizer for plant bio stimulation, wherein the organic fertilizer comprises pelleted lysed lactic acid bacteria (LABs) and / or Plant Growth Promoting Microorganisms (PGPMs) comprising bio-active compounds, wherein said bio-active compounds comprise at least 12 wt% lactic acids and organic acids at most 3 wt% alcohols at least 15 wt% one or more enzyme at least 0,5 wt% sugars5 to 25 wt% fatty acids, and0,002 to 0, 18 wt% plant hormones, based on the total dry weight of the organic fertilizer.

11. The organic fertilizer according to claim 10, wherein the pelleted lysed LABs is one or more selected from the group consisting of Lactoplantibacillus, Lactobacillus, Lactobacillus paracasei, Lactococcus, Leuconostoc, Bifidobacterium, Brevibacterium, Streptococcus, preferably Lactobacillus paracasei12. The organic fertilizer according to claim 10 or 11, wherein the pelleted lysed PGPMs is one or more selected from the group consisting of Azospirillum, Azotobacter, Rhizobium, Bradyrhizobium, Sinorhizobium, Ensifer, Pseudomonas, Bacillus, Burkholderia, Gluconacetobacter, Gluconobacter, Acetobacter, Variovorax, Streptomyces, Paraburkholderia, Acinetobacter, Arthrobacter, Paenibacillus, Chriseobacter, Lysobacter, Saccharomyces, Colletotrichum, Beauveria and Trichoderma, preferably Azospirillum.

13. The organic fertilizer according to any one of the claims 10 to 12, wherein the organic fertilizer is obtained by a method according to any one of the claims 1 to 9.

14. The organic fertilizer according to any one of the claims 10 to 13, wherein the organic fertilizer is a liquid organic fertilizer.

15. The organic fertilizer according to any one the claims 10 to 14, wherein said plant bio stimulation is of a plant, preferably a horticultural crop, more preferably a horticultural crop selected from a lettuce or a tomato plant.

16. A use of an organic fertilizer of any one of claim 10 to 15 for plant bio stimulation.

17. The use according to claim 16, wherein 100 to 6000 g of said organic fertilizer is dissolved in 200 to 500 L of aqueous solution, preferably in water, per 1 hectare of soil receiving said organic fertilizer.

18. The use according to claim 16 or 17, wherein the organic fertilizer is added to a plant, preferably to the soil of said plant, at sowing, plant germination, plant sprouting or plant transplantation, plant growth phase or plant reproduction, preferably at plant sprouting or plant transplantation.

19. The use according to any one of the claims 16 to 18, wherein said plant bio stimulation is of a plant preferably a horticultural crop, more preferably a horticultural crop selected from a lettuce or a tomato plant.

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