New consortium of rhizospheric and / or endophytic bacteria promoting plant growth

Abstract

The present invention relates to a consortium of isolated bacteria that has an application in agriculture. In particular, the described rhizospheric and / or endophytic bacteria can provide a benefit to an agricultural plant derived from a seed, a seedling, a cutting, a seedling, or any plant tissue.

Description

Title of the invention: Novel consortium of rhizospheric and / or endophytic bacteria promoting plant growth

[0001] The present invention relates to a consortium of isolated bacteria that has an application in agriculture. In particular, the described rhizospheric and / or endophytic bacteria can provide a benefit to an agricultural plant derived from a seed, seedling, cutting, seedling, or any plant tissue. Technological background

[0002] Economically, environmentally and socially sustainable approaches to agriculture and food production are needed to meet the needs of a growing world population. By 2050, the Food and Agriculture Organization of the United Nations projects that total food production will have to increase significantly to meet the needs of a growing population, under increasingly challenging conditions, notably due to dwindling freshwater resources, rising energy prices, increased costs of natural or industrial fertilizers and plant protection products (pesticides, fungicides, insecticides, etc.) and the likely need for crops to adapt to the pressures of a drier, hotter and more extreme global climate.The need to produce more food with less water in drier climates creates a crucial need for innovations in plant tolerance to various environmental stresses.

[0003] Crop performance can be optimized primarily through technologies focused on the interaction between the crop genotype (e.g., plant breeding, genetically modified (GM) crops) and its environment (e.g., fertilizers, synthetic herbicides, or pesticides). While these technologies have contributed to increasing global food production over the past few decades, new, innovative, efficient, environmentally sustainable, and publicly acceptable approaches to improving crop yields are desirable.

[0004] This is how, for example, the role of rhizosphere and / or endophytic bacteria in improving agricultural production is known. For example, plant growth-promoting rhizobacteria (PGPR) colonize the rhizosphere using root exudates as a nutrient substrate, while providing a beneficial effect to the plant, such as growth stimulation. Four effects The main ones have been identified in these RFCPs. They can increase nutrient availability, regulate phytohormone production, increase tolerance to abiotic stresses and inhibit pests through competition.

[0005] Rhizobacteria belong to different taxonomic groups of bacteria such as: Bacillus, Pseudomonas, Azospirilum or Rhizobium.

[0006] Rhizobacteria such as Kosakonia or Pantoea, isolated from commercial crops, including maize, rice, sugarcane, cotton, and wheat, are also known to promote the growth of host plants. The effect of these bacterial strains on plant growth promotion is attributed to their ability to biologically fix atmospheric nitrogen, dissolve natural phosphates, and secrete plant growth hormones.

[0007] The present invention addresses the important issue of improving crop performance and aims to develop a bacterial composition capable of synergistically increasing the performance of agricultural crops, in particular plant nitrogen nutrition and growth.

[0008] The present application proposes an environmentally sustainable solution based on a consortium of rhizospheric and / or endophytic bacteria to enhance crop performance and increase agricultural production yields without relying on increased water consumption or increased nitrogen fertilizer inputs. Summary of the invention

[0009] The use of rhizospheric and / or endophytic bacteria promoting plant growth can therefore be an effective tool for improving crop growth and productivity under difficult environmental conditions, including poor soil fertility.

[0010] Biofertilizers based on live bacteria constitute an interesting alternative to chemical fertilizers because they provide nutrients to plants, reduce soil-borne diseases and improve soil health and quality.

[0011] According to a first aspect, the invention relates to a bacterial consortium comprising two strains of rhizospheric and / or endophytic bacteria, isolated and purified, respectively from the genera Kosakonia and Pantoea.

[0012] According to a second aspect, the invention relates to a biostimulant composition comprising said bacterial consortium and an agriculturally acceptable support.

[0013] According to a third aspect, the invention relates to a use of said biostimulant composition to promote the growth of a plant. Detailed description of the invention

[0014] As used herein, the term “microbial consortium” or “bacterial consortium” refers to a composition of at least two bacteria of different genera or species different ones fulfilling a common function, or participating in the modification of a phenotypic trait of a plant. More particularly, according to the present invention, the bacterial consortium comprises or consists of two bacteria respectively from the genera Kosakonia and Pantoea or from the species Kosakonia oryzae and Pantoea cypripedii.

[0015] As used herein, the term "biostimulating composition" refers to a composition comprising the consortium of the invention and an agriculturally acceptable carrier, which stimulates plant nutrition processes with the aim of improving one or more of the following characteristics of plants or their rhizosphere:

[0016] a) the efficiency of nutrient use;

[0017] b) tolerance to abiotic stress;

[0018] c) qualitative characteristics;

[0019] d) the availability of nutrients confined in the soil or rhizosphere. »

[0020] As used here, the term “agricultural composition” refers to the agriculturally acceptable substrate.

[0021] As used here, the term "colonized" refers to the presence of bacteria from the bacterial consortium on, within, or in the immediate environment of any part of the plant. For example, microorganisms can colonize the intracellular or extracellular systems of plant tissues, including leaves, stems, flowers, fruits, seeds, or roots; these are referred to as endophytes. As another example, microorganisms can colonize the immediate environment in the soil and on the surface of a plant's roots; these are referred to as rhizospheric microorganisms. According to the invention, a rhizospheric and / or endophytic bacterium can be, for example, an isolated and purified bacterium of the genus Kosakonia and / or Pantoea, and can confer a beneficial property to the host plant, such as an increase in biomass yield.

[0022] Preferably, bacteria of the genera Kosakonia and Pantoea or of the species Kosakonia oryzae and Pantoea cypripedii can colonize the rhizosphere of plants.

[0023] Endophytes, that is to say microorganisms capable of entering into an endosymbiotic relationship with a plant host, are particularly useful in the present invention.

[0024] Whether an isolated and purified bacterium of the genus Kosakonia and / or Pantoea is or is not an endophyte is determined according to a particular host plant and / or particular bacterial species.

[0025] As used herein, the term "biomass" refers to the total mass or weight (fresh or dry), at a given time, of a plant tissue, plant tissues, an entire plant, or a population of plants. Biomass is generally expressed in weight per unit of area. The term can also refer to all plants or species in the community.

[0026] As used here, the term “isolated” is specifically intended to refer to a bacterium that is purified of the additional components with which it was originally associated in its natural state.

[0027] According to the present invention, RFCP bacterial strains of the bacterial consortium are isolated from Guyanese soil.

[0028] In certain aspects of the description, the isolated bacterial strains exist in the form of isolated and biologically pure cultures. Those skilled in the art will understand that an isolated and biologically pure culture of a particular bacterial strain means that said culture is substantially free from other living organisms and contains only bacteria from a single strain of either the genus Kosakonia or the genus Pantoea.

[0029] As used herein, the term “16S rRNA” refers to the 16S ribosomal RNA (rRNA) sequence of a bacterium. Sequencing the 16S rRNA gene is a well-established method for studying bacterial phylogeny and taxonomy.

[0030] As used here, a nucleic acid has "homology" or is "homologous" to a second nucleic acid if the nucleic acid sequence has a sequence similar to the second nucleic acid sequence. The terms "identity," "sequence identity percentage," or "identical" in the context of nucleic acid sequences refer to residues in the two sequences that are identical when aligned for maximum match. There are several known algorithms that can be used to establish the identity of nucleotide sequences. For example, polynucleotide sequences can be compared using FASTA, Gap, or Bestfit. FASTA provides alignments and a sequence identity percentage of regions with the best overlap between the query and search sequences. (Pearson, 1990, Methods Enzymol. 183:63-98).The term "substantial homology" or "substantial similarity" indicates that, when a nucleic acid or sequence of nucleic acids is optimally aligned with appropriate nucleotide insertions or deletions with another nucleic acid (or its complementary strand), there is nucleotide sequence identity for at least about 95%, 96%, 97%, 98%, 99%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9%, or 100% of the nucleotide bases, as measured by any well-known sequence identity algorithm.

[0031] As used herein, the term "colony forming unit" ("CFU") is used as a measure of viable microorganisms in a sample. One CFU is a a viable individual cell capable of forming, on a solid medium, a visible colony whose individual cells originate from a parent cell by cell division.

[0032] As used herein, the term "growth medium" refers to any medium suitable for the growth of a plant. By way of example, media may be natural or artificial and include, but are not limited to: soil, potting mixes, bark, vermiculite, hydroponic solutions alone and applied to solid plant support systems, and tissue culture gels. It should be understood that media may be used alone or in combination with one or more other media. They may also be used with or without the addition of exogenous nutrients and physical support systems for the roots and foliage.

[0033] As used herein, the term “culture medium” means any medium suitable for the growth of rhizospheric and / or endophytic bacterial strains (RFCP) of the bacterial consortium.

[0034] Thus, according to a first aspect, the present invention therefore proposes a bacterial consortium comprising at least two isolated and purified rhizospheric and / or endophytic bacterial strains, comprising or consisting respectively of:

[0035] a) a bacterial strain of the genus Kosakonia selected from the list consisting of the following species: Kosakonia arachidis, Kosakonia cowanii, Kosakonia oryzae, Kosakonia oryziphila, Kosakonia oryzendophytica, Kosakonia pseudosacchari, Kosakonia radicincitans, Kosakonia sacchari and Kosakonia quasisacchari, and

[0036] b) a bacterial strain of the Pantoea genus chosen from the list consisting of the following species: Pantoea agglomerons, Pantoea allii, Pantoea ananatis, Pantoea anthophila, Pantoea brenneri, Pantoea coffeiphila, Pantoea conspicua, Pantoea cypripedii, Pantoea deleyi, Pantoea dispersa, Pantoea eucalypti, Pantoea eucrina, Pantoea leporis, Pantoea piersonii, Pantoea rodasii, Pantoea rwandensis, Pantoea septica, Pantoea stewartii, Pantoea vagan, Pantoea wallisii.

[0037] Advantageously the bacterial consortium comprises two rhizospheric and / or endophytic bacterial strains, isolated and purified, chosen from the two lists above.

[0038] According to particular embodiments, the microbial consortia may include any combination of at least one bacterial strain of the genus Kosakonia with at least one bacterial strain of the genus Pantoea.

[0039] Advantageously, the bacterial consortium comprises or consists of:

[0040] a) a bacterial strain of the species Kosakonia oryzae, and

[0041] b) a bacterial strain of the species Pantoea cypripedii.

[0042] Even more advantageously, the bacterial consortium comprises or consists of:

[0043] a) a bacterial strain of the genus Kosakonia, having a 16S rRNA sequence that exhibits at least 95%, 96%, 97%, 98%, 99%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100% sequence identity with SEQ ID NO: 1,

[0044] b) a bacterial strain of the genus Pantoea, having a 16S rRNA sequence that exhibits at least 95%, 96%, 97%, 98%, 99%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100% sequence identity with SEQ ID NO: 2.

[0045] In preferred embodiments of the invention, the bacterial consortium comprises or consists of:

[0046] a) a bacterial strain of the species Kosakonia oryzae, having a 16S rRNA sequence that exhibits at least 95%, 96%, 97%, 98%, 99%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100% sequence identity with SEQ ID NO: 1,

[0047] b) a bacterial strain of the species Pantoea cypripedii, having a 16s rRNA sequence that exhibits at least 95%, 96%, 97%, 98%, 99%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100% sequence identity with SEQ ID NO: 2.

[0048] Advantageously, the bacterial consortium comprises or consists of:

[0049] a) a bacterial strain of the genus Kosakonia, having a 16S rRNA sequence that exhibits at least 95%, 96%, 97%, 98%, 99%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100% sequence identity with SEQ ID NO: 1, isolated from soils of French Guiana

[0050] b) a bacterial strain of the genus Pantoea, having a 16S rRNA sequence which exhibits at least 95%, 96%, 97%, 98%, 99%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100% sequence identity with SEQ ID NO: 2, isolated from the soils of French Guiana.

[0051] Even more advantageously, the bacterial consortium comprises or consists of a mixture comprising

[0052] a) a bacterial strain of the genus Kosakonia, having a 16S rRNA sequence of sequence SEQ ID NO: 1,

[0053] b) a bacterial strain of the genus Pantoea, having a 16S rRNA sequence of sequence SEQ ID NO: 2,

[0054] said mixture is filed with the CNCM on July 4, 2024 under CNCM accession filing number 1-6102.

[0055] Even more advantageously, the bacterial consortium consists of a mixture of 2 bacterial strains of the genus Kosakonia and of the genus Pantoea, filed with the CNCM on July 4, 2024 under the number CNCM 1-6102. Bacterial consortium preparation

[0056] Each active bacterial strain of the genera Kosakonia and Pantoea can be obtained by incubating said strain in a culture medium, for example a culture medium containing an autolytic yeast extract at 30 °C for at least 16 hours, particularly between 16 hours and 24 hours and preferably by centrifuging a culture medium to obtain a pellet and dissolving the pellet in another culture medium, for example peptone water containing 0.1% peptone.

[0057] The active culture can be prepared from a frozen stock of the strain or from a lyophilized powder. A lyophilized powder of a strain according to the present invention can be prepared using conventional methods known to those skilled in the art. Lyophilization of a bacterial strain is preferably carried out in the presence of a cryoprotectant such as lactose or polyvinylpyrrolidone or a mixture thereof.

[0058] More specifically, active bacterial strains of the genera Kosakonia and Pantoea can be produced in flasks (erlenmeyer, bottle).

[0059] More specifically, active bacterial strains of the genera Kosakonia and Pantoea can be produced in a bioreactor.

[0060] Advantageously, a stock suspension from flask production contains from 1 x 103 to 1 x 1010 CFU / mL, preferably at least 109 CFU / mL.

[0061] Advantageously, a stock suspension from bioreactor production contains from 1 x 103 to 1 x 1015 CFU / mL, preferably at least 1010 CFU / mL.

[0062] Advantageously, the bacterial consortium according to the invention is prepared by mixing a suspension containing 1 x 103 to 1 x 1015 CFU / mL of a bacterial strain of the genus Kosakonia with a suspension containing 1 x 103 to 1 x 1015 CFU / mL of a bacterial strain of the genus Pantoea, the ratio of the CFU load of the two bacterial strains of the consortium is from 1:10 to 10:1, preferably from 1:2 to 2:1, even more preferably 1:1.

[0063] Bacterial suspensions from flask or bioreactor production can be concentrated or diluted by decantation, filtration or centrifugation, to an appropriate concentration.

[0064] According to a second aspect, the invention relates to a biostimulant composition comprising said bacterial consortium and an agriculturally acceptable support.

[0065] Advantageously, the biostimulant composition comprises said bacterial consortium in which the ratio of the CFU load of a bacterial strain of the genus Kosakonia and a bacterial strain of the genus Pantoea is from 1:10 to 10:1, preferably from 1:2 to 2:1, even more preferably 1:1.

[0066] Advantageously, the biostimulant composition comprises said bacterial consortium containing 1 x 103 to 1 x 1015 CFU / mL of a bacterial strain of the genus Kosakonia and 1 x 103 to 1 x 1015 CFU / mL of a bacterial strain of the genus Pantoea.

[0067] Preferably, the biostimulant composition comprises a mixture of a suspension containing 1 x 10³ to 1 x 10¹⁵ CFU / mL of a bacterial strain of the genus Kosakonia and a suspension containing 1 x 103 to 1 x 1015 CFU / mL of a bacterial strain of the genus Pantoea, preferably at least 108 CFU / mL of each bacterial strain.

[0068] Advantageously, said support is liquid, semi-solid (gel) or solid.

[0069] Advantageously, said support is an aqueous solution (nutrient culture medium, buffer solution). The biostimulant composition thus constitutes an aqueous suspension.

[0070] Advantageously, said support is semi-solid and constitutes a culture medium (agar), a polymer gel, wet peat.

[0071] Advantageously, said support is solid and is in the form of powder, pellets, granules (peat, plaster, lignite ...), particles (cellulose).

[0072] Advantageously, the bacterial strains of the consortium are encapsulated in a solid support in particular in inert polymeric matrices such as alginate beads / granules or acrylic polymers, or polysaccharides, or natural or biosynthetic gums (algae, plants, seeds, flour)

[0073] According to one embodiment of the present invention, the bacterial consortium is available in the form of granules, or soil soaking which are applied to the plant growth medium.

[0074] According to a particular embodiment, said support may refer to a plant growth medium or an agricultural composition.

[0075] In one embodiment, the plant growth medium is a natural medium such as soil, sand, mud, clay, humus, regolith, rock, or water. In another embodiment, the growth medium is artificial. Such an artificial growth medium may be constructed to mimic the conditions of a natural environment; however, this is not necessary. Artificial growth media may be made from one or more materials from any number and combination, including sand, minerals, rock, metals, salts, nutrients, and water. In one embodiment, the growth medium is sterile. In another embodiment, the growth medium is not sterile.

[0076] The medium can be modified or enriched with additional compounds or components, for example, a component that can aid in the interaction and / or selection of specific groups of microorganisms with the plant and among themselves. For example, nutrients (e.g., organic and inorganic minerals (such as phosphorus, nitrogen salts, ammonia, potassium) and micronutrients such as cobalt and magnesium).

[0077] In some embodiments, the bacteria of the consortium are combined in agricultural compositions. In some embodiments, the compositions agricultural agents used in the present invention include, but are not limited to: wetting agents, compatibilizing agents (also called "compatibility agents"), antifoaming agents, cleaning agents, sequestering agents, drift-reducing agents, neutralizing and buffering agents, corrosion inhibitors, colorants, odorizing agents, spreading agents (also called "spreaders"), penetration aids (also called "penetrants"), sticking agents (also called "stickers" or "binders"), dispersing agents, thickening agents (also called "thickeners"), stabilizers, emulsifiers, cryoprotectants.

[0078] In some embodiments, the agricultural compositions used in the present invention are solid. In certain embodiments, the present invention teaches the use of supports comprising, but not limited to: mineral earths such as silicas, silica gels, silicates, talc, kaolin, attaclay, limestone, chalk, loess, clay, dolomite, diatomaceous earth, calcium sulfate, magnesium sulfate, magnesium oxide, ground synthetic materials, fertilizers such as ammonium sulfate, ammonium phosphate, ammonium nitrate, thiourea and urea, plant-based products such as cereal flours, tree bark flour, wood flour and nutshell flour, cellulose powders, attapulgites, montmorillonites, mica, vermiculites, synthetic silicas and synthetic calcium silicates.

[0079] In some embodiments, the agricultural compositions of the present invention are liquid. Thus, in some embodiments, the present invention teaches that the agricultural compositions described herein may comprise compounds or salts such as monoethanolamine salt, sodium sulfate, potassium sulfate, sodium chloride, potassium chloride, sodium acetate, ammonium hydrogen sulfate, ammonium chloride, ammonium acetate, ammonium formate, ammonium oxalate, ammonium carbonate, ammonium hydrogen carbonate, ammonium thiosulfate, ammonium hydrogen diphosphate, ammonium dihydrogen monophosphate, ammonium sodium hydrogen phosphate, ammonium thiocyanate, ammonium sulfamate, or ammonium carbamate.

[0080] In certain embodiments, the present invention teaches that agricultural compositions may comprise binders such as: polyvinylpyrrolidone, polyvinyl alcohol, partially hydrolyzed polyvinyl acetate, carboxymethylcellulose, starch, vinylpyrrolidone / vinyl acetate copolymers and polyvinyl acetate, or compositions thereof; lubricants such as magnesium stearate, sodium stearate, talc, or polyethylene glycol, or compositions thereof; antifoams such as silicone emulsions, long-chain alcohols, phosphoric esters, acetylenediols, fatty acids or organofluorine compounds, and complexing agents such as: ethylenediaminetetraacetic acid (EDTA) salts, trinitrilotriacetic acid salts or polyphosphoric acid salts, or mixtures thereof.

[0081] In some embodiments, agricultural compositions include surfactants. In some embodiments, surfactants are added to liquid agricultural compositions. In other embodiments, surfactants are added to solid formulations, particularly those designed to be diluted with a carrier before application. Thus, in some embodiments, agricultural compositions include surfactants. Surfactants are sometimes used, alone or with other additives, such as mineral or vegetable oils, as adjuvants in spray tank mixtures to improve the biological performance of bacteria on the target. The types of surfactants used for bioimprovement generally depend on the nature and mode of action of the bacteria. Surfactants may be anionic,cationic or nonionic, and can be used as emulsifying agents, wetting agents, suspending agents, or for other purposes. In some embodiments, the surfactants are nonionic, such as alkyl ethoxylates, linear aliphatic alcohol ethoxylates, and aliphatic amine ethoxylates. In certain embodiments, the present invention teaches the use of surfactants comprising alkali, alkaline earth, or ammonium metal salts of aromatic sulfonic acids, for example ligno-, phenol-, naphthalene-, and dibutylnaphthalenesulfonic acids, and fatty acids of arylsulfonates, alkyl ethers, lauryl ethers, fatty alcohol sulfates, and fatty alcohol glycol ether sulfates, condensates of sulfonated naphthalene and its derivatives with formaldehyde, condensates of naphthalene or naphthalenesulfonic acids with phenol and formaldehyde, condensates of phenol or phenolsulfonic acid with formaldehyde,Phenol condensates with formaldehyde and sodium sulfite, polyoxyethylene octylphenyl ether, isooctyl-, octyl- or nonylphenol ethoxylate, tributylphenyl polyglycol ether, alkylaryl polyether alcohols, isotridecyl alcohol, ethoxylated castor oil, ethoxylated triarylphenols, phosphated triarylphenol ethoxylates, lauryl alcohol polyglycol ether acetate, sorbitol esters, used lignin-sulfite liquors or methylcellulose, or compositions thereof.

[0082] In certain embodiments, the present invention teaches other suitable surfactants, including alkyl sulfate salts, such as diethanolammonium lauryl sulfate; alkylarylsulfonate salts, such as calcium dodecylbenzenesulfonate; alkylphenol-alkylene oxide admixtures, such as nonylphenol-C18 ethoxylate; alcohol-alkylene oxide admixtures, such as tridecyl alcohol-C16 ethoxylate; soaps, such as sodium stearate; alkylnaphthalene sulfonate salts, such as sodium dibutylnaphthalenesulfonate; dialkyl esters of sulfosuccinate salts, such as sodium di(2-ethylhexyl)sulfosuccinate; sorbitol esters, such as sorbitol oleate; quaternary amines, such as lauryltrimethylammonium chloride; polyethylene glycol esters of fatty acids, such as polyethylene glycol stearate; sequenced copolymers of ethylene oxide and propylene oxide; mono- and dialkyl phosphate ester salts; vegetable oils such as soybean oil, rapeseed / canola oil, olive oil, castor oil, sunflower oil, coconut oil, corn oil, cottonseed oil, linseed oil, palm oil, peanut oil, safflower oil, sesame oil, tung oil and the like; and esters of the above vegetable oils, in particular methyl esters.

[0083] In some embodiments, agricultural compositions include wetting agents. A wetting agent is a substance that, when added to a liquid, increases the spreading or penetrating power of the liquid by reducing the interfacial tension between the liquid and the surface over which it spreads. Wetting agents are used for two main functions in agrochemical formulations: during processing and manufacturing to increase the wetting rate of powders in water to produce soluble liquid concentrates or suspension concentrates; and during the mixing of a product with water in a spray tank or other container to reduce the wetting time of wettable powders and to improve water penetration into water-dispersible granules.In some embodiments, examples of wetting agents used in the agricultural compositions of the present invention, including wettable powders, concentrated suspensions and water-dispersible granule formulations, are: sodium lauryl sulfate; sodium dioctyl sulfosuccinate; alkylphenol ethoxylates; and aliphatic alcohol ethoxylates.

[0084] In some embodiments, the agricultural compositions used in the present invention include dispersing agents. A dispersing agent is a substance that adsorbs onto the surface of particles and helps to maintain the dispersion state of the particles and prevents their reaggregation. In some embodiments, dispersing agents are added to the agricultural compositions of the present invention to facilitate dispersion and suspension during manufacturing, and to ensure the redispersion of the particles in water in a spray tank. In some embodiments, dispersing agents are used in wettable powders, concentrated suspensions, and water-dispersible granules. The surfactants used as dispersing agents have the ability to to adsorb strongly onto the surface of a particle and provide a charged or steric barrier to particle reaggregation. In some embodiments, the most commonly used surfactants are anionic, nonionic, or mixtures of both types.

[0085] In some embodiments, the agricultural compositions include dispersing agents such as sodium lignosulfonates. In some embodiments, the suspended concentrates offer very good adsorption and stabilization using polyelectrolytes, such as sodium naphthalene sulfonate formaldehyde condensates. In some embodiments, tristyrylphenol ethoxylate phosphate esters are also used. In some embodiments, alkylarylethylene oxide condensates and EO-PO sequence copolymers are sometimes combined with anionic agents as dispersing agents for the suspended concentrates.

[0086] In some embodiments, the agricultural compositions used in the present invention comprise polymeric surfactants. In some embodiments, the polymeric surfactants have very long hydrophobic "skeletons" and a large number of ethylene oxide chains forming the "teeth" of a "comb-like" surfactant. In some embodiments, these high molecular weight polymers can impart very good long-term stability to the suspended concentrates, because the hydrophobic skeletons have numerous anchoring points on the particle surfaces.In some embodiments, examples of dispersing agents used in the agricultural compositions of the present invention are: sodium lignosulfonates; sodium naphthalene sulfonate and formaldehyde condensates; tristyrylphenol ethoxylate phosphate esters; aliphatic alcohol ethoxylates; alkyl ethoxylates; EO-PO sequenced copolymers; and grafted copolymers.

[0087] In some embodiments, the agricultural compositions used in the present invention include emulsifying agents. An emulsifying agent is a substance that stabilizes a suspension of droplets of one liquid phase in another liquid phase. Without the emulsifying agent, the two liquids would separate into two immiscible liquid phases. In some embodiments, the most commonly used emulsifying mixtures include an alkylphenol or an aliphatic alcohol with 12 or more ethylene oxide units and the oil-soluble calcium salt of dodecylbenzene sulfonic acid. A range of hydrophilic-lipophilic equilibrium (“HLB”) values ​​from 8 to 18 will normally provide good, stable emulsions. In some embodiments, the stability of the emulsion can sometimes be improved by adding a small amount of a block copolymer surfactant EO-PO.

[0088] In some embodiments, the agricultural compositions used in the present invention comprise solubilizing agents. A solubilizing agent is a surfactant that will form micelles in water at concentrations above the critical micelle concentration. The micelles are then capable of dissolving or solubilizing water-insoluble materials within the hydrophobic portion of the micelle. The types of surfactants commonly used for solubilization are nonionic: sorbitan monooleates; sorbitan monooleate ethoxylates; and methyl oleate esters.

[0089] In some embodiments, agricultural compositions include gelling agents. Thickeners or gelling agents are mainly used in the formulation of concentrated suspensions and emulsions to modify the rheology or flow properties of the liquid and to prevent the separation and sedimentation of dispersed particles or droplets. Thickening, gelling, and anti-seedling agents generally fall into two categories: water-insoluble particles and water-soluble polymers. It is possible to produce concentrated suspension formulations from clays and silicas. In some embodiments, agricultural compositions include one or more thickeners, including, but not limited to: montmorillonite, for example, bentonite; aluminum and magnesium silicate; and attapulgite.In some embodiments, the present invention teaches the use of polysaccharides as thickening agents. The most commonly used types of polysaccharides are natural extracts from seeds and algae or synthetic cellulose derivatives. Some embodiments use xanthan gum, and others use cellulose. In some embodiments, the present invention teaches the use of thickening agents including, but not limited to: guar gum; locust bean gum; carrageenan; alginates; methylcellulose; sodium carboxymethylcellulose (SCMC); and hydroxyethylcellulose (HEC). In some embodiments, the present invention teaches the use of other types of anti-seedling agents such as modified starches, polyacrylates, polyvinyl alcohol, and polyethylene oxide. Another good anti-seedling agent is xanthan gum.

[0090] In some embodiments, the presence of surfactants, which lower interfacial tension, can cause foaming of water-based formulations during mixing operations in production and during application through a spray tank. Therefore, in some embodiments, in order to reduce the tendency to foam, antifoaming agents are often added either during the production step or before filling the bottles / spray tanks. Generally, there are two types of antifoaming agents, namely silicones and non-silicones. Silicones are generally aqueous emulsions of dimethylpolysiloxane, while non-silicone antifoaming agents are water-insoluble oils, such as octanol and nonanol, or silica. In both cases, the function of the antifoaming agent is to displace the surfactant from the air-water interface.

[0091] In some embodiments, the agricultural compositions include a preservative.

[0092] Furthermore, microbial consortia can be combined with known agricultural active ingredients, such as pesticides, herbicides, bactericides, fungicides, insecticides, virucides, acaricides, nematicides, plant growth regulators, rodenticides, anti-algal agents, biocontrol agents, or beneficial agents. In addition, microbial consortia can be combined with known organic fertilizers and soil amendments. However, these known active ingredients must be applied at least one week after the application of the microbial consortia to limit the antagonistic effect of the plant protection products.

[0093] According to a third aspect, the invention relates to a use of said biostimulant composition to promote the growth of a plant, in particular the increase of the biomass of a plant.

[0094] Bacterial strains of the genera Kosakonia and Pantoea are known to:

[0095] - Fix atmospheric nitrogen

[0096] - Solubilize the phosphorus present in the soils

[0097] - Produce siderophores

[0098] - To produce auxin (growth hormone)

[0099] - To produce 1'-aminocyclopropane-l-carboxylate (ACC) deaminase allowing limit the effects of water stress

[0100] The bacterial strains of the consortium according to the invention:

[0101] a) a bacterial strain of the genus Kosakonia, having a 16S rRNA sequence of sequence SEQ ID NO: 1,

[0102] b) a bacterial strain of the genus Pantoea, having a 16S rRNA sequence of sequence SEQ ID NO: 2,

[0103] constituting the mixture filed with the CNCM on July 4, 2024 under accession filing number CNCM 1-6102, have been characterized in the laboratory and also show the biochemical functions mentioned above.

[0104] According to embodiments, the invention relates to an efficient and widely applicable agricultural platform using said biostimulant composition which promotes one or more properties beneficial to a plant species, for example: increased growth, increased yield, increased nitrogen use efficiency, increased drought tolerance.

[0105] In certain respects, the bacterial strains comprising the consortium act synergistically. In certain respects, the effect that the microbial consortium exhibits on a certain plant characteristic is greater than the effect that would be observed if one of the individual microbial members of the consortium had been used alone. In other words, in certain respects, the consortium has a more than additive effect on a desired plant characteristic, compared to the effect that would be observed if one of the individual members of the consortium had been used alone.

[0106] According to certain embodiments of the invention, the use of said biostimulant composition makes it possible to increase the yield of agricultural crops. These yield increases can be achieved without the need to add more fertilizer.

[0107] Advantageously, said biostimulant composition can be used optionally in the presence of fertilizer or organic amendment according to the farmer's usual cultivation practice, his usual technical route.

[0108] Preferably, the chosen organic fertilizer or amendment provides a source of nitrogen (N), phosphorus (P), potassium (K) and magnesium oxide (MgO).

[0109] A soil amendment helps to structure and fertilize the soil. It improves its physical, chemical, and biological condition by providing organic and / or mineral elements to compensate for any deficiencies. It differs from fertilizer, which delivers nutrients directly to the plant and therefore has a more limited effect over time. The amendment can be of organic origin (plant or animal), mineral origin, or may come from the composting of organic waste (food waste, green waste). The nutrients are released over time.

[0110] Advantageously, the biomass of plants treated with said biostimulant composition may be about 1 to 10% higher, 10 to 20% higher, 20 to 30% higher, 30 to 40% higher, 40 to 50% higher, 50 to 60% higher, 60 to 70% higher, 70 to 80% higher, 80 to 90% higher or more compared to a control culture in the absence of biostimulant composition or compared to a culture treated with a single bacterial strain, either of the genus Kosakonia or of the genus Pantoea.

[0111] In certain aspects, the consortia described herein provide a wide range of agricultural applications, including: improvements in grain, fruit, and flower yields; improvements in the growth of plant parts; improved survival capacity in extreme climates; and improvements in other desired plant phenotypic characteristics. It is important to note that these benefits for plants can be achieved without any harmful side effects on the environment. Plant and seed treatment

[0112] In certain embodiments, the present invention relates to the treatment of seeds before they are sown or planted with said biostimulant composition of the present invention to promote the growth of a plant, in particular the increase of the biomass of a plant.

[0113] Advantageously, the present invention relates to the treatment of a seed, a seedling, a cutting, a seedling, any plant tissue or a plant with said biostimulant composition of the present invention to promote the growth of a plant, in particular the increase of the biomass of a plant.

[0114] Seed treatment can be a coating applied directly to an untreated seed. However, seed treatment can also be a seed coating applied to a seed that has already been coated with one or more seed coatings or treatments. Seed treatments can comprise one or more active compounds, chemical or biological, and one or more inert ingredients.

[0115] Seed treatment generally refers to the application of a material to a seed before or during its planting in the soil. Treating seeds with the bacterial consortium of the invention, optionally in combination with an agricultural composition of the present invention, has the advantage of delivering the treatments at the planting site before seed germination and seedling emergence. Application methods

[0116] In embodiments, said biostimulant composition of the present invention is applied by inoculation, spraying or pulverizing.

[0117] As used here, the term "sprinkling" refers to watering by an automated irrigation system which will operate by projecting liquid (e.g. water comprising a culture medium and the bacterial consortium in suspension) in the form of fine drops in the air.

[0118] As used here, the term “spraying” refers to manual watering by projecting liquid in the form of fine drops.

[0119] As used herein, the term "inoculation" refers to the entire process of inoculating the root of a plant, seedling, or seedling with a biostimulant composition according to the invention. Any liquid, semi-solid, or solid composition can be used to "treat" plant roots. Liquid compositions can be applied to the surface. Granulated compositions can be placed on the surface for plants with shallow roots in loose soils. For deep roots, it is preferable to create channels leading to the root zone.

[0120] Advantageously, 1 to 2 weeks after sowing, at the 2-leaf stage of the seedling, the biostimulant composition is inoculated at the base of the seedling stem. Advantageously, the "Bacterial Consortium" corresponds to 1 mL concentrated at least 108 CFU / mL of each bacterial strain in the mixture per cell (cell volume of seed trays ranging from 50 to 150 mL on seed trays) on moist soil.

[0121] Advantageously, 1 to 2 weeks after sowing, at the 2-leaf stage of the seedling, the biostimulant composition is inoculated at the base of the stem of the potted seedling. Advantageously, the "Bacterial Consortium" corresponds to 10 mL concentrated at a minimum of 10⁸ CFU / mL of each bacterial strain in the mixture per pot (pot volumes ranging from 750 to 1250 mL) on moist soil.

[0122] Advantageously, 1 to 2 weeks after sowing, at the 2-leaf stage of the plant, the biostimulant composition is sprayed onto the cultivated plant in the open field. Advantageously, the spraying corresponds to a volume of 50 L to 400 L per hectare (depending on the crop) of at least 10⁸ CFU of each bacterial strain in the mixture / mL.

[0123] The biostimulant composition can be applied to a plant, a seedling, a cutting, a seedling or any plant tissue, by spraying.

[0124] In another embodiment, the biostimulant composition can be applied directly to a plant seed before sowing.

[0125] In another embodiment, the biostimulant composition can be applied directly to a plant seed, as a seed coating.

[0126] In another embodiment, the biostimulant composition can be formulated as granules and applied alongside the seeds during planting. The granules can also be applied after planting. The granules can also be applied before planting.

[0127] In some embodiments, the biostimulant composition is administered to a plant or a growth medium by soaking to improve plant growth, yield and crop quality.

[0128] According to embodiments, the biostimulant composition can be formulated as: solutions; wettable powders; sprinkleable powders; soluble powders; concentrated emulsions or suspensions; seed dressings or coatings; water-dispersible granules; water-soluble granules (slow- or fast-release); microencapsulated granules or suspensions; and as irrigation components, among other things. In some aspects, the compositions can be diluted in an aqueous medium before conventional spraying. The compositions of the present invention can be applied to the soil, the plant, the seed, the rhizosphere, or any other area to which it would be advantageous to apply the microbial compositions.

[0129] According to one embodiment, the bacterial strains of the consortium infiltrate parts of the plant such as roots, stems, leaves and / or reproductive plant parts (and become endophytes), and / or develop on the surface of roots, stems, leaves and / or reproductive plant parts, plant parts and / or grow in the plant rhizosphere. In one embodiment, the bacterial strains of the consortium form a symbiotic relationship with the plant.

[0130] Advantageously, the plant is treated by inoculation or spraying with the biostimulant composition. Alternatively, the biostimulant composition can be coated with the seed before planting.

[0131] According to embodiments, the plants are chosen from vegetables / fruits, field crops, pastures and cover crops, tropical crops and other forest trees, preferably cucumber, lettuce, cabbage, melon, sugar cane, banana, papaya.

[0132] According to some embodiments, the plants are chosen from:

[0133] a) Vegetables / fruits: garlic, dill, artichoke, asparagus, eggplant, beetroot vegetable, broccoli, cardoon, carrot, celeriac and stalk, tuberous chervil, chicory, the different types of cabbage, the different salads, garden cress, land cress, crosne, cucumber, gherkins, courgette, melon, watermelon, potimarron, pumpkin, shallot, spinach, fennel, broad bean, flageolet bean, strawberry, beans, lettuce, lentils, lamb's lettuce, corn, turnip, black-eyed pea, onion, parsnip, parsley, chili pepper, leek, peas, bell pepper, potato, radishes, horseradish, rhubarb, rocket, rutabaga, salsify, curly endive, scorzonera, tomato and Jerusalem artichoke;

[0134] b) field crops: corn (Zea mays L), rice (Oryza sativa, Oryza glaberrina), the different species of wheat (Triticum aestivum; Triticumspelta; Triticum durum; Triticum dicoccum; Triticum turgidum L. subsp.turanicum; Triticum monococcum), barley (Hordeum vulgareL. subsp.vulgare; hordeum hexastichum); sorghum (Sorghum bicolor); oats (Avena sativa), millet (Pennisetum glaucum; Panicum milliaceum; Setaria italica; Panicum sumatrense), rye (Secale cereale), triticale (Triticosecale), soybeans (Glycine max);

[0135] c) pastures and cover plants: the different pastures (genus Andropogon, Brachiaria, Cenchrus, Chloris, Cynodon, Dactylis, Digitaria, Echinochloa, Hyparrhenia, Lolium, Melinis, Panicum, Pennisetum, Setaria, Tripsacum...) and the different cover plants (genus Arachis, Brachiaria, Canavalia, Centrosema, Chrysopogo, Crotalaria, Cymbopogon, Desmodium, Dolichos, Galactia, Lotus, Medicago, Mucuna, Neonotonia, Pueraria, Stylosanthes, Trifolium);

[0136] d) Tropical crops: pineapple, avocado, banana, grapefruit, various lemons (yellow, green), mandarin, orange, pitaya, cassava, pumpkin, the watermelon, acerola cherry, cocoa, coffee, cashew, breadfruit, starfruit, coconut, guava, jackfruit, lychee, rambutan, tamarind, sapodilla, pistachio, mangosteen, West Indian apricot, kaffir lime, kumquat, soursop, cocoa, star apple, camu-camu, durian, mombin, ambarella, quenette, cupuacu, parepou, wassai, sugar cane, passion fruit, taro, cassava, sweet potato, taro, yam, mango and papaya;

[0137] e)les arbres forestiers : du genre Abarema, Adenanthera, Albizia, Anacardium, Andira, Aniba, Apeiba, Aspidosperma, Bagassa, Bellucia, Bixa, Caesalpinia, Carapa, Cas sia, Ceiba, Clitoria, Clusia, Couratari, Couroupita, Delonix, Dicorynia, Dipteryx, Eperua, Eriotheca, Euterpe, Genipa, Gossypium, Goupia, Heretiera, Hevea, Himatanthus, Humiria, Hura, Hymanea, Hymenolobium, Inga, Lecythis, Leucaena, Majidea, Mauritia, Milleta, Mouriri, Oenocarpus, Ormosia, Parinari, Parkia, Pithecellobium, Platonia, Protium, Pterocarpus, Senna, Sesbania, Spathodea, Spondias, Tabebuia, Tachigali, Talipariti, Tamarindus, Tapirira, Terminalia, Theobroma, Varronia, Virola.

[0138] The invention presently claimed is what is defined in the claims. Experimental Partie

[0139] Les exemples qui suivent illustrent l'invention.

[0140] All the following examples serve to illustrate the invention described above.

[0141] Example 1: Sequence analysis and phylogenetic assignment

[0142] To characterize the isolated bacterial strains, they underwent marker gene sequencing, and the sequences were analyzed to provide taxonomic classifications. The isolated bacterial strains underwent PCR amplification of the 16S rRNA gene using a 27f / 1492r primer set (according to Chou-Fei et al. (2013)), and Sanger sequencing of the paired ends was performed using two primer sets (24f / 1492r and 533R / 787F). The raw chromatograms were converted to sequences, and the corresponding quality scores were assigned using TraceTuner v3.0.6beta. These sequences were filtered for quality using PRINSEQ v0.20.3 with left and right cut quality score thresholds of 30 and a quality window of 20 bp. Taxonomic classifications were assigned to the sequences using the NCBI and Silva databases.

[0143] The 16S rRNA gene sequence of sequence SEQ ID NO: 1 (below) is identified as belonging to a bacterial strain of the genus Kosakonia.

[0144] The 16S rRNA gene sequence of sequence SEQ ID NO: 2 (below) is identified as belonging to a bacterial strain of the genus Pantoea.

[0145] [Tables 1] SEQ ID NO : CTTCACCCCAGTCATGAATCACAAAGTGGTAAGCGCCCTCCCGAA 1 GGTTAAGCTACCTACTTCTTTTGCAACCCACTCCCATGGTGTGAC GGGCGGTGTGTACAAGGCCCGGGAACGTATTCACCGTGACATTCT GATTCACGATTACTAGCGATTCCGACTTCATGGAGTCGAGTTGCA GACTCCAATCCGGACTACGACGCACTTTATGAGGTCCGCTTGCTC TCGCGAGGTCGCTTCTCTTTGTATGCGCCATTGTAGCACGTGTGTA GCCCTGGTCGTAAGGGCCATGATGACTTGACGTCATCCCCACCTT CCTCCAGTTTATCACTGGCAGTCTCCTTTGAGTTCCCGGCCGGACC GCTGGCAACAAAGGATAAGGGTTGCGCTCGTTGCGGGACTTAAC CCAACATTTCACAACACGAGCTGACGACAGCCATGCAGCACCTGT CTCACAGTTCCCGAAGGCACCCCGGCATCTCTGCCAGGTTCTGTG GATGTCAAGACCAGGTAAGGTTCTTCGCGTTGCATCGAATTAAAC CACATGCTCCACCGCTTGTGCGGGCCCCCGTCAATTCATTTGAGT TTTAACCTTGCGGCCGTACTCCCCAGGCGGTCGATTTAACGCGTT AGCTCCGGAAGCCACGCCTCAAGGGCACAACCTCCAAATCGACA TCGTTTACGGCGTGGACTACCAGGGTATCTAATCCTGTTTGCTCCC CACGCTTTCGCACCTGAGCGTCAGTCTTCGTCCAGGAGGCCGCCT TCGCCACCGGTATTCCTCCAGATCTCTACGCATTTCACCGCTACAC CTGGAATTCTACCTCCCTCTACGAGACTCCAGCCTGCCAGTTTCG AATGCAGTTCCCAGGTTGAGCCCGGGGATTTCACATCCGACTTGA CAGACCGCCTGCGTGCGCTTTACGCCCAGTAATTCCGATTAACGCTTGCACCCTCCGTATTACCGCGGCTGCTGGCACGGAGTTAGCCGG TGCTTCTTCTGCGGGTAACGTCAATCAGCACGGTTATTAACCGTA CCGCCTTCCTCCCCGCTGAAAGTGCTTTACAACCCGAAGGCCTTC TTCACACACGCGGCATGGCTGCATCAGGCTTGCGCCCATTGTGCA ATATTCCCCACTGCTGCCTCCCGTAGGAGTCTGGACCGTGTCTCA GTTCCAGTGTGGCTGGTCATCCTCTCAGACCAGCTAGGGATCGTC GCCTAGGTGGGCCRTTACCCCGCCTACNAGCTAATCCCATCTGGG CACATCTGATGGCAAGAGGCCYGAAGGTCCCCCTCTTTGGTCTTG CGACGTTATGCGGTATTAGCTACCGTTTCCAGTAGTTATCCCCCTC CATCAGGCAGTTTCCCAGACATTACTCACCCGTCCGCCACTCGTC ACCCGAGAGCAAGCTCTCTGTGCTACCGTTCGACTTGCATGTGTT AGGCCTGCCGCCAGCGTTCAATCTGA SEQ ID NO : TTCACCCCAGTCATGAATCACAAAGTGGTAAGCGCCCTCCCGAAG 2 GTTAAGCTACCTACTTCTTTTGCAACCCACTCCCATGGTGTGACG GGCGGTGTGTACAAGGCCCGGGAACGTATTCACCGTGGCGTTCTG ATCCACGATTACTAGCGATTCCGACTTCACGGAGTCGAGTTGCAG ACTCCGATCCGGACTACGACGCACTTTATGAGGTCCGCTTGCTCT CGCGAGGTCGCTTCTCTTTGTATGCGCCATTGTAGCACGTGTGTA GCCCTGGCCGTAAGGGCCATGATGACTTGACGTCATCCCCACCTT CCTCCGGTTTATCACCGGCAGTCTCCTTTGAGTTCCCGACCGAATC GCTGGCAACAAAGGATAAGGGTTGCGCTCGTTGCGGGACTTAAC CCAACATTTCACAACACGAGCTGACGACAGCCATGCAGCACCTGT CTCACGGTTCCCGAAGGCACCAAGGCATCTCTGCCAAGTTCYGTG GATGTCAAGGCCAGGTAAGGTTCTTCGCGTTGCATCGAATTAAAC CACATGCTCCACCGCTTGTGCGGGCCCCCGTCAATTCATTTGAGT TTTAACCTTGCGGCCGTACTCCCCAGGCGGTCGACTTAACGCGTT AGCTCCGGAAGCCACTCCTCAAGGGAACAGCCTCCAAGTCGACA TCGTTTACGGCGTGGACTACCAGGGTATCTAATCCTGTTTGCTCCC CACGCTTTCGCACCTGAGCGTCAGTCTTTGTCCAGGGGGCCGCCT TCGCCACCGGTATTCCTCCAGATCTCTACGCATTTCACCGCTACAC CTGGAATTCTACCCCCCTCTACAAGACTCTAGCCTGCCAGTTTCG AATGCAGTTCCCAGGTTAAGCCCGGGGATTTCACATCCGACTTGA CAGACCGCCTGCGTGCGCTTTACGCCCAGTAATTCCGATTAACGC TTGCACCCTCCGTATTACCGCGGCTGCTGGCACGGAGTTAGCCGG TGCTTCTTCTGCGGGTAACGTCAATGACGAAGCGTATTAAGCTTC ATCCCTTCCTCCCCGCTGAAAGTACTTTACAACCCGAAGGCCTTC TTCATACACGCGGCATGGCTGCATCAGGCTTGCGCCCATTGTGCAATATTCCCCACTGCTGCCTCCCGTAGGAGTCTGGACCGTGTCTCA GTTCCAGTGTGGCTGGTCATCCTCTCAGACCAGCTAGGGATCGTC GCCTAGGTGAGCCGTTACCCCACCTACTAGCTAATCCCATCTGGG TTCATCCGATAGTGAGAGGCCCGAAGGTCCCCCTCTTTGGTCTTG CGACGTTATGCGGTATTAGCCACCGTTTCCAGTGGTTATCCCCCTC TACCGGGCAGATCCCCAGACATTACTCACCCGTCCGCCACTCGCC ACCCGA

[0146] The 16S rRNA sequence with sequence SEQ ID NO: 1 exhibits 99.78% homology with strain Ola51n (accession number CP014007), which is a bacterial strain of the species Kosakonia oryzae.

[0147] The 16S rRNA sequence with sequence SEQ ID NO: 2 shows 100% homology with strain LMG 2657 (accession number JQ711145), which is a bacterial strain of the species Pantoea cypripedii isolated from a cypripedium orchid in California, USA (Brady et al., 2010). Example 2#: Production of bacterial strains a) Production in flask

[0148] The following protocol is applied:

[0149] Inoculate Pantoea and Kosakonia separately into 2 glass flasks containing sterile LB-Lennox medium (Bactopeptone: 10 g / L; Sodium chloride: 5 g / L; Yeast extract: 5 g / L; flask filled to a maximum of 60% of the total volume). Incubate the flasks with gentle shaking at a temperature of 30 °C for 24 hours. Mix the 2 resulting suspensions. b) Production in a Bioreactor

[0150] The following protocol is applied:

[0151] Prepare the bioreactors with LB-Lennox medium (Bactopeptone: 10 g / L; Sodium chloride: 5 g / L; Yeast extract: 5 g / L). Inoculate one bioreactor with the Pantoea strain and one bioreactor with the Kosakonia strain to obtain an initial optical density (at 600 nm) of 0.1 before growth. Configure both bioreactors with the following culture conditions: 30°C, 700 rpm, pH 7, aeration at 100 L / h (mass flow rate at 1.66 SLPM). Incubate for 15 h. Then mix the two resulting suspensions.

[0152] Example 3: Increase in lettuce biomass

[0153] The main objective of the experiment implemented is to verify the increase in biomass of an agricultural plant in the presence of the biostimulant composition of the invention.

[0154] The experimental procedures are as follows:

[0155] Witness (T): farmer's usual practice

[0156] Strain 1 (SI): usual farmer practice + inoculation with bacterial strain of the genus Kosakonia, having a 16S rRNA sequence of sequence SEQ ID NO: 1 forming part of the mixture filed with the CNCM on July 4, 2024 under CNCM accession filing number 1-6102.

[0157] Strain 2 (S2): usual farmer practice + inoculation with bacterial strain of the genus Pantoea, having a 16S rRNA sequence of sequence SEQ ID NO: 2 forming part of the mixture filed with the CNCM on July 4, 2024 under CNCM accession filing number 1-6102.

[0158] Consortium of the 2 strains (I): usual practice of the farmer + inoculation with the bacterial consortium which consists of

[0159] a) a bacterial strain of the genus Kosakonia, having a 16S rRNA sequence of sequence SEQ ID NO: 1,

[0160] b) a bacterial strain of the genus Pantoea, having a 16S rRNA sequence of sequence SEQ ID NO: 2,

[0161] as filed with the CNCM on July 4, 2024 under CNCM accession filing number 1-6102.

[0162] [Tables2] Groups Number of applications Application Dose applied per plant (10⁸ CFU / m²) Water dose per plant in nursery Strain S1 1 In seed tray 1 mL / Strain S2 1 In seed tray 1 mL / Consortium (I) 1 In seed tray 1 mL / Control / / / 1 mL Experimental conditions

[0163] The experiment is carried out in Montsinery.

[0164] The trial takes place in a greenhouse, under homogeneous growing conditions of sucrine lettuce.

[0165] All plants come from the same cohort (same sowing date). Nursery production

[0166] Sowing date: 25 / 08 / 2023

[0167] Seedling well size: 60 mL

[0168] Substrate type: fine structure potting soil, suitable for the production of plants in plugs of 3 to 10cm, made up of black peat which promotes re-moistening and limits the shrinkage of the plugs (K Proline Potgrond)

[0169] Fertilization program: 5 days after sowing, add every 4 days a universal foliar fertilizer containing nutrients (Nitrogen, Phosphorus, Potassium) and trace elements essential for plant nutrition (Algoflash).

[0170] Irrigation method: with a watering can (once a day) After planting

[0171] Fertilisation programme: 25 kg of physiolite for the greenhouse, 30 gr of chicken manure per plant at planting and Algoflash universal foliar fertilizer 1 week before planting, then 2 times a week after planting.

[0172] Spraying is carried out on the aerial part of the plants to moisten the surface of the leaves without runoff, i.e. about 1 to 3 sprays of 2 mL each per plant depending on the age and therefore the size of the plant.

[0173] Plant protection treatment program: 1 treatment of Décis and Ortiva at planting

[0174] Irrigation method: sprinkler once a day, approximately 100 liters per day for the 248 m² greenhouse Experimental setup

[0175] The experiment consists of 40 individuals per treatment, divided into 5 replicates of 8 individuals. The average biomasses were therefore calculated from 40 values ​​for each condition (control SI, S2 and consortium). Results

[0176] The average biomasses of the plants are as follows:

[0177] [Tables3] Control 38.73 g Strain 1 43.63 g Strain 2 45.53 g Bacterial Consortium (I) 57.95 g

[0178] Calculation of the percentage (%) increase in biomass compared to the control:

[0179] [Tables4] Strain 1 +12.66% Strain 2 +17.56% Bacterial consortium +49.63% Statistical analysis

[0180] First, a Shapiro-Wilk test is used to check whether the data distribution follows a normal distribution. This test having a "p-value" less than 0.05 (i.e., p-value = 0.00188): the data distribution does not follow a normal distribution.

[0181] A Kruskal-Wallis test is then applied to indicate whether at least one data group exhibits values ​​significantly different from at least one of the other data groups, among the different experimental modalities (Control (T), Strain 1 (SI), Strain 2 (S2) and Consortium (I)). The p-value of this test being less than 0.05 (i.e. p-value=0.0002289), this test shows that at least one data group is significantly different from at least one other data group.

[0182] Finally, a Dunnett test was used to analyze the presence or absence of a significant difference between all the different data groups. This test is therefore used to compare all the different categories with each other. It provides different results depending on whether the difference is significant or not: - "ns": non-significant result - “*”: significant result (p-value < 0.05) - “**”: highly significant result (p-value < 0.005) _ « *** » • extremely significant result (p-value < 0.0005)

[0183] This test showed significant results between certain modalities.

[0184] Dunnett's test provides the following results:

[0185] [Tables5] Group 1 Group 2 Number Number p-value Significant power Bacterial Consortium (I) Strain 1 40 40 0.00288 ** Bacterial Consortium (I) Strain 2 40 40 0.0191 * Bacterial Consortium (I) Control 40 40 0.000352 *** Strain 1 Strain 2 40 40 1 ns Strain 1 Control 40 40 1 ns Strain 2 Control 40 40 1 ns Conclusion

[0186] There are no significant differences between the "Control" group, "strain 1" group and the "strain 2" group, although an increase in biomass compared to the control can be observed of 12.66% for strain 1 and 17.56% for strain 2. These increases are not statistically significant.

[0187] A significant difference (p-value < 0.05) was observed between the "Bacterial Consortium" group and the "Strain 2" group. This therefore shows that the "Bacterial Consortium" exhibits a clear difference compared to strain 2 used alone.

[0188] A strong significant difference (p-value < 0.005) was also observed between the "Bacterial Consortium" group and the "Strain 1" group. This therefore shows that the Bacterial Consortium exhibits a very clear difference compared to strain 1 used alone.

[0189] Finally, an extremely strong significant difference (p-value < 0.0005) is present between the "Bacterial Consortium" group and the "Control" group. This therefore shows that the Bacterial Consortium shows an extreme difference compared to the control without bacteria (inoculated biomass improved by 49.63% compared to the control).

[0190] This test demonstrates a synergy between the two bacterial strains of the consortium on the biomass of sucrine lettuce. Indeed, the sucrine lettuces inoculated with the bacterial consortium of the invention showed a significantly higher average biomass compared to the control (p-value < 0.0005) and to strains 1 (p-value < 0.005) and 2 (p-value < 0.05) used alone.

Claims

Demands

1. A bacterial consortium comprising at least two isolated and purified rhizospheric and / or endophytic bacterial strains, comprising or consisting of: a) a bacterial strain of the genus Kosakonia selected from the list consisting of the following species: Kosakonia arachidis, Kosakonia cowanii, Kosakonia oryzae, Kosakonia oryziphila, Kosakonia oryzendophytica, Kosakonia pseudosacchari, Kosakonia radicincitans, Kosakonia sacchari and Kosakonia quasisacchari, and b) a bacterial strain of the genus Pantoea selected from the list consisting of the following species: Pantoea agglomerans, Pantoea allii, Pantoea ananatis, Pantoea anthophila, Pantoea brenneri, Pantoea coffeiphila, Pantoea conspicua, Pantoea cypripedii, Pantoea deleyi, Pantoea dispersa, Pantoea eucalypti, Pantoea eucrina, Pantoea leporis, Pantoea piersonii, Pantoea rodasii, Pantoea rwandensis, Pantoea septica, Pantoea stewartii, Pantoea vagan, Pantoea wallisii.

2. Bacterial consortium according to claim 1, comprising or consisting of: a) a bacterial strain of the species Kosakonia oryzae, b) a bacterial strain of the species Pantoea cypripedii.

3. Bacterial consortium according to claim 1, comprising or consisting of: a) a bacterial strain of the genus Kosakonia, having a 16s rRNA sequence that exhibits at least 95%, 96%, 97%, 98%, 99%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100% sequence identity with SEQ ID NO: 1, b) a bacterial strain of the genus Pantoea, having a 16s rRNA sequence that exhibits at least 95%, 96%, 97%, 98%, 99%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100% sequence identity with SEQ ID NO:

2.

4. Bacterial consortium according to claim 1, comprising or consisting of a mixture of 2 bacterial strains, of the genus Kosakonia and of the genus Pantoea, filed with the CNCM on July 4, 2024 under number CNCM 1-6102.

5. Biostimulant composition comprising the bacterial consortium according to any one of claims 1 to 4 and an agriculturally acceptable carrier.

6. Composition according to claim 5, wherein the ratio of the CFU load of a bacterial strain of the genus Kosakonia and a bacterial strain of the genus Pantoea is from 1:10 to 10:1, preferably from 1:2 to 2:1, more preferably 1:1

7. Composition according to claim 6, comprising a mixture of a suspension containing 1 x 103 to 1 x 1015 CFU / mL of a bacterial strain of the genus Kosakonia and a suspension containing 1 x 103 to 1 x 1015 CFU / mL of a bacterial strain of the genus Pantoea, preferably at least 108 CFU / mL of each bacterial strain.

8. Use of the biostimulant composition according to any one of claims 5 to 7 to promote the growth of a plant, in particular the increase of the biomass of a plant.

9. Use of the biostimulant composition according to claim 8, wherein the plant is treated by inoculation, sprinkling or spraying.

10. Use of the biostimulant composition according to claim 8 or 9, wherein the plant is selected from vegetables / fruits, field crops, pastures and cover crops, tropical crops and other forest trees, preferably cucumber, lettuce, cabbage, melon, sugar cane, banana, papaya.