Use of guar gum for microbial growth

Abstract

The present application relates to the use of guar gum for microbial growth. In particular, the present application relates to the in vitro use of guar gum for maintaining or increasing the growth rate of a microorganism.

Description

[0001] This application is a divisional application of the following application: Application date: November 29, 2019; Application number: 2019800788326; Invention name: "Use of guar gum for microbial growth".

[0002] This application claims priority to USPA No. 62 / 772,780, filed November 29, 2018, the entire contents of which are incorporated herein by reference for all purposes. 1. Technical Field

[0003] The present invention relates to the use of guar (guar) gum for the growth of microorganisms, particularly bacteria. 2. Background Technology

[0004] Microorganisms may have beneficial effects on the medium they interact with. Therefore, it is useful to seed this medium with these microorganisms. Once the microorganisms are deposited on the target medium, they need to grow and therefore survive in a specific environment where a bacterial community is already present. Therefore, it is crucial that the microorganisms are still able to grow and reproduce in the target medium despite the presence of this bacterial community.

[0005] Therefore, skilled artisans seek ingredients that can be used in formulations, such as phytosanitary formulations, which will create an environment that improves the growth of microorganisms.

[0006] As the world's population grows, the demand for food increases. As a result, biostimulants are increasingly used in agricultural production worldwide.

[0007] The speed at which plant roots reach nutrients is a key parameter for the initial successful development and growth of the plant, typically in the first few weeks. Biostimulants help improve plant growth by providing nutrients from natural products or by helping the plant access nutrients.

[0008] Biostimulants promote plant growth and development throughout the crop lifecycle, from seed germination to plant maturity. They improve plant metabolic efficiency, thereby enhancing breeding and improving quality. They increase plant tolerance and resilience to abiotic stresses. They promote the absorption, transfer, and utilization of nutrients. They improve the quality of agricultural products, including the sugar content, color, and size of fruits. Furthermore, they regulate and improve plant water content. Finally, they enhance certain physical and chemical properties of the soil and promote the development of aboveground microorganisms.

[0009] The use of microorganisms or mixtures of microorganisms for plant biostimulation is well known. These methods are based on the application of compositions containing purified microorganisms or mixtures of microorganisms. Such compositions contain, in particular, Bacillus strains.

[0010] To date, the major drawback regarding the use of microorganisms as plant biostimulants has been the difficulty in maintaining this activity.

[0011] There is therefore a need to find ways to maintain or even improve the activity and efficiency of biostimulants such as microorganisms, in particular bacteria.

[0012] There is also a need to find ways to specifically maintain or improve the growth of target microorganisms in a given culture medium. 3. Summary of the Invention

[0013] The present invention therefore relates to the in vitro use of guar (guar) gum for maintaining or increasing the growth rate of microorganisms.

[0014] According to the present invention, the growth rate of microorganisms, in particular bacteria, can be measured by the following method:

[0015] The microorganisms were cultured in a medium containing guar gum. Samples were taken at different times to determine the number of colony forming units (CFU) using the plating method. Using this method, the number of bacterial cells (expressed as CFU) was obtained over time. The growth of microorganisms follows an exponential law: N t =N0e (μt) , where μ is the growth rate of the microorganism. The value of the microbial growth rate μ is obtained by fitting the experimental data on a logarithmic scale, which corresponds to ln(N t ) slope over time (linear graph: ln(N t )=ln(N0)+μt).

[0016] According to an embodiment, the present invention relates to the in vitro use of guar (guar) gum for maintaining or increasing the growth rate of microorganisms.

[0017] The present invention is therefore based on the use of guar gum which is able to maintain and keep constant the biostimulant effect of microorganisms, in particular bacteria, over time and in other words to maintain the growth rate of microorganisms and in particular bacteria.

[0018] Advantageously, the use of guar gum can increase the biostimulant effect of microorganisms, in particular bacteria, in other words, can increase the growth rate of microorganisms and in particular bacteria.

[0019] Preferably, according to the present invention, when guar gum as defined above is used, the growth rate of the microorganism is increased by at least 5%, preferably at least 10%, compared to the growth rate of the microorganism when no guar gum is used.

[0020] According to an embodiment, the present invention relates to the in vitro use of guar (guar) gum for increasing the growth rate of microorganisms.

[0021] The present invention also relates to the use of guar (guar) gum for maintaining or increasing the growth rate of microorganisms on plants, on seeds or in soil.

[0022] The present invention also relates to the use of guar (guar) gum for maintaining or increasing the growth rate of bacteria on plants, on seeds or in soil.

[0023] Thus, according to an embodiment, the present invention relates to agrochemicals and more particularly to the field of plant quarantine.According to an embodiment, guar (guar) gum as mentioned above is applied to plants or seeds. 4. Specific Implementation Methods

[0024] Throughout this specification, including the claims, the term "comprising one" or "comprising a" should be understood as being synonymous with the term "comprising at least one", and unless otherwise indicated, "between..." and "from..." should be understood to include the limits.

[0025] As used herein, "weight percent," "wt%," "percent by weight," "% by weight," and variations thereof refer to the concentration of a substance when the weight of that substance is divided by the total weight of the composition and multiplied by 100.

[0026] Should the disclosure of any patents, patent applications, and publications incorporated herein by reference conflict with the description of the present application to the extent that a term is unclear, the present description shall take precedence.

[0027] guar gum

[0028] In this application, guar refers to the plant Guar bean. Guar (guar) gum as defined above may be used in the composition.

[0029] In this application, "guar seed" refers to a seed derived from the guar bean. Guar seeds consist of a husk (which is more or less fibrous), a germ, and two "guar sheets" or "endosperm halves" that make up the guar's endosperm. The "sheets (or endosperms)" are rich in galactomannan. Guar seeds typically consist of 35% to 40% endosperm by weight, 42% to 47% germ by weight, and 14% to 17% husk by weight.

[0030] In this application, "guar gum flour" or "guar gum powder" refers to a powder derived from the endosperm of guar beans.

[0031] In this application, "native guar gum" refers to macromolecular chains of the galactomannan type derived from the endosperm of guar beans, which have not been chemically modified by the grafting of chemical groups. Natural guar gum comprises macromolecules containing a backbone of D-mannopyranose units linked in the β(1-4) positions, which are replaced by D-galactopyranose units in the β(1-6) positions. The mannose / galactose ratio of natural guar gum is approximately 2.

[0032] In the present application, "guar (guar) guar gum" (also referred to as "guar gum") refers to a product consisting essentially of natural guar gum (in the form of guar gum flakes, or guar gum flour or powder).

[0033] As used herein, the "average molecular weight" of guar gum refers to the weight average molecular weight of the guar gum.

[0034] According to any of the embodiments of the present invention, the guar gum of the present invention can have an average molecular weight (Mw) between 2,000 Daltons and 5,000,000 Daltons. In one embodiment, the guar gum of the present invention can have an average molecular weight (Mw) between 100,000 Daltons and 4,500,000 Daltons, such as between 500,000 Daltons and 4,000,000 Daltons, such as between 1,000,000 Daltons and 3,500,000 Daltons, such as between 2,000,000 and 3,500,000 Daltons.

[0035] In another embodiment, the guar gum of the present invention can have an average molecular weight (Mw) between about 2,000 and 90,000 Daltons, such as between about 5,000 and 60,000 Daltons, such as between about 5,000 and 40,000 Daltons, such as between about 8,000 and 30,000 Daltons.

[0036] The average molecular weight of guar gum can be measured by GPC (gel permeation chromatography), for example, using a Shodex OH Pak column and an Agilent refractive index detector.

[0037] The composition containing guar gum can be a solid or liquid composition. In the case where the composition is solid, the composition can be in the form of a powder, granules, agglomerates, flakes, pellets, pellets, tablets, bricks, pastes, blocks (such as molded blocks), unit doses, or another solid form known to those skilled in the art. Preferably, the solid composition is in the form of a powder or pellets.

[0038] In some aspects, the composition containing the guar gum is in the form of granules. The granules containing guar gum can be prepared in a three-step process: wet granulation, then drying and screening. The wet granulation step is notably directed to introducing and mixing guar gum powder and carrier and optionally other ingredients in a granulation device (such as a mixing granulator). Carry out this mixing, wherein water is sprayed onto this mixture. The wet granulation step will produce a wet granule containing guar gum. The weight ratio between the carrier to be mixed and the guar gum can be between 20: 1 and 1: 1, preferably between 20: 1 and 10: 1. Based on the gross weight of the wet granule, the water content introduced can be included between 10wt% and 50wt%. The carrier can be silicon-dioxide, amorphous silicon-dioxide, precipitated silicon-dioxide, hydrated amorphous silicon-dioxide, precipitated silicon-dioxide, hydrated amorphous synthetic calcium silicate, hydrophobized precipitated silica (hydrofobizedprecipitated silica), silica gel, sodium aluminum silicate, clay, zeolite, bentonite, layered silicate, kaolin, sodium carbonate, sodium bicarbonate, sodium sulfate, sodium tripolyphosphate, sodium chloride, sodium silicate (water glass), magnesium chloride, calcium chloride, ammonium chloride, magnesium sulfate, calcium carbonate, calcium oxide and / or calcium sulfate or its mixture. Notably, the carrier is selected from calcium chloride and calcium carbonate. The drying step is notably related to these wet granules by using a hot air stream to dry. The step can be carried out in a fluidized bed equipped with an air inlet and an air outlet generally. The screening step can be carried out by using a vibrating plate.

[0039] The pellets may have a diameter of 0.1 to 6 mm. Generally, normal pellets have a diameter of 2-6 mm, and microgranules have a diameter of 0.1-2 mm. Preferably, microgranules with a diameter of 0.5-1.6 mm are used.

[0040] Alternatively, pellets containing guar gum can be prepared by using extrusion methods well known to those skilled in the art. These extrusion methods are described in U.S. Patent No. 6,146,570. For example, guar gum and a carrier and optionally other ingredients can be blended by heating. The weight ratio between the carrier and the guar gum can be between 20:1 and 1:1. The adhesive can then be melted and introduced into the mixture of guar gum and the carrier. The extrusion step can then be carried out with an extruder temperature maintained between 55°C and 65°C. Soft, warm pellets can be formed and can subsequently be cooled to a freezing point (e.g., at room temperature) below the melting adhesive to obtain solid pellets.

[0041] In the case where the seed treatment composition is liquid, this liquid composition can be a solution in a suspension, a dispersion, a slurry, a liquid carrier (selected from water, an organic solvent oil or its mixture).Can be prepared by using a conventional method by mixing guar bean (guar) gum as described above with a liquid carrier, optionally with other components.Preferably, this liquid composition is in the form of an aqueous solution.In one embodiment, method of the present invention comprises the step of wherein coating seed with a composition as above.Then the seed of this coating can be applied on the soil or in the soil, notably so that the seed of this coating is contacted with the soil.

[0042] Suitable coating techniques can be utilized to coat seeds or aggregates of seeds with compositions according to the present invention. Equipment that can be used for coating may include, but is not limited to, drum coaters, rotary coaters, tumble drums, fluidized beds, and spouted beds. It should be understood that any suitable equipment or technology known to those skilled in the art can be used. Seeds can be coated by batch or continuous coating processes. Seeds can be coated with compositions according to the present invention that are in solid form or liquid form. Preferably, aqueous dispersions or solutions are used.

[0043] The seeds can be separated before the coating step. In one embodiment, mechanical means such as sieves can be used to separate the seeds. The separated seeds can then be introduced into a coating machine with a seed reservoir. In one embodiment, the seeds are combined with the composition described herein, optionally with a binder and / or adhesive, in a mixing tank.

[0044] In some aspects, one or more coatings comprising a composition according to the present invention may be added to the seeds or agglomerates thereof.The outer layers may be introduced sequentially by coating the seeds or agglomerates thereof in a rotating drum.

[0045] Agglomerants or agglomerant devices can also be used. Coating can be carried out in a rotary coating machine by placing the seeds in a rotating chamber that pushes the seeds against the inner wall of the chamber. Centrifugal force and a mixing rod placed in the coating machine rotate the seeds and mix them with a coating layer that contains a composition according to the present invention. An adhesive or other coating material can be pumped into the approximate center of the coating machine onto an atomizer disk that rotates with the coating chamber. Upon impact with the atomizer disk, the liquid adhesive is then directed outwardly onto the seeds in small droplets.

[0046] Seed coating technology also comprises, for example, seed is placed in rotating disk or drum.Then with water or other liquid spray these seeds and then fine inert powder (for example, diatomaceous earth) is added gradually on this coating disk.Each atomized seed becomes the center of the mass body of the coating that powder, layer or size increase gradually.Then by the tumbling action in this disk, this mass body is rounded and smoothed, similar to the cobblestone on the beach.The compaction action of the weight of material in this disk is these coating layers compacted.When approaching this coating process end, often in conjunction with adhesive, the outer layer of this mass body is hardened.Adhesive can also reduce the amount of dust produced by processing, transporting and sowing finished product.Frequently utilize screening technology (as, frequent manual screening) to eliminate blank or double body thing, and guarantee uniform size.For example, the tolerance of seed coating composition described here can be + / -1 / 64 inch (0.4mm), which is the U.S. seed size industry standard, is based on and introduces coating long ago. For example, coated lettuce seeds are most frequently sown with a belt planter through 8 / 64 inch (3.2 mm) diameter round holes in the belt. This hole size requires that the lettuce seeds coated with the composition according to the present invention can be sized to pass through a 7.5 / 64 inch (3.0 mm) screen and through an 8.5 / 64 inch (3.4 mm) screen.

[0047] In one embodiment of the present invention, the seed can be contacted with the composition using an "in situ coating" process, notably by implanting the seed of the plant in a hole or ditch in the soil, and then applying a composition according to the present invention to surround or partially surround the seed or adjacent to the seed so that the seed is in contact with the composition, notably with guar gum. According to the present invention, the hole can be a hole, cavity or hollow area. The seed can be a seed that has not been processed by any reagent, or a seed that has been processed but not processed with a composition of the present invention using agricultural chemicals (such as fungicides and insecticides). Preferably, the composition is deposited on the carrier before application to provide granules or microgranules. Granules or microgranules containing guar gum can be prepared using the above method.

[0048] In yet another embodiment, guar gum according to the present invention (or a composition containing the same) is applied to soil in which a plant is grown. Seeds of the plant can then be applied to the soil so that the seed comes into contact with the composition, and notably, with the guar gum. Notably, the composition can be used in liquid form (e.g., as an aqueous solution / dispersion) or in solid form (e.g., as a powder or pellets).

[0049] Preferably, the application of the seeds and the application of the composition according to the invention are carried out mechanically. It will be understood that either or both of the applications mentioned may also be carried out manually.

[0050] According to a preferred embodiment, the guar (guar) gum as defined above is used in liquid form.

[0051] In one embodiment of the present invention, guar (guar) gum is used in an amount ranging from 50 to 500 g per quintal of seeds.

[0052] microorganism

[0053] "Microorganism" as used herein means a microscopic organism that can exist in its single-cell form or as a colony of cells. In specific embodiments, the microorganism is single-celled.

[0054] More specifically, the present invention relates to soil microorganisms, also known as soil microbes.

[0055] According to an embodiment, the microorganisms are fungi, in particular unicellular fungi, or bacteria.

[0056] In specific embodiments, the microorganisms are bacteria.

[0057] According to an embodiment, the bacteria according to the present invention are selected from Gram-positive bacteria.

[0058] As used herein, the term "Gram-positive bacteria" refers to bacterial cells that stain purple (positive) in a Gram staining assay. The Gram stain binds to the peptidoglycan that is abundant in the cell walls of Gram-positive bacteria. In contrast, the cell walls of "Gram-negative bacteria" have a thin layer of peptidoglycan, so Gram-negative bacteria do not retain the stain and allow for absorption of the counterstain in the Gram staining assay.

[0059] Gram-positive bacteria are well known to the skilled person and include bacteria from the genera Actinomycetes, Actinomyces, Arthrobacter, Bifidobacterium, Frankia, Gardnerella, Lysinibacillus, Microbacterium, Micrococcus, Micromonospora, Mycobacterium, Nocardia, Rhodococcus, Streptomyces, Bacillus, Clostridium, Listeria, Enterococcus, Lactobacillus, Leuconostoc, Mycoplasma, Ureaplasma, Lactococcus, Paenibacillus, Pediococcus, Acetobacter, Eubacterium, Heliobacterium, Heliospirillum and Murina.

[0060] In a specific embodiment, the Gram-positive bacteria are selected from the group consisting of: Actinomycetes, Actinomyces, Arthrobacter, Bifidobacterium, Frankia, Lysinibacillus, Microbacterium, Micrococcus, Micromonospora, Nocardia, Rhodococcus, Streptomyces, Bacillus, Listeria, Lactobacillus, Leuconostoc, Lactococcus, Paenibacillus, Pediococcus, Acetobacter, Eubacterium, Heliobacter, Spirillum and Murina.

[0061] In a specific embodiment, the Gram-positive bacterium is a bacterium from the genus Bacillus, in particular a bacterium selected from the group consisting of: Bacillus itcheniformis, Bacillus megaterium (e.g., Bacillus megaterium strain CCT0536), Bacillus pumilus (e.g., Bacillus pumilus strain GB34 (YieldShield; Bayer), Bacillus pumilus strain QST2808 (Sonata; Bayer), and Bacillus pumilus strain BU F-33), Bacillus licheniformis (e.g., Bacillus licheniformis strain SB3086 (EcoGuard; Novozymes) and Bacillus licheniformis strain DSM17236), Bacillus vegetable, Bacillus mojavensis, Bacillus subtilis (e.g., Bacillus subtilis strain GB03 (Kodiak; Bayer), MBI 600 (Subtilex; Becker Underwood), and QST 713 (Serenade; Bayer AG), Bacillus subtilis strain GB122 plus, Bacillus subtilis strain EB120, Bacillus subtilis strain J-P13, Bacillus subtilis FB17, Bacillus subtilis strains QST30002 and QST3004 (NRRL B-50421 and NRRLB-50455), sandpaper mutants of Bacillus subtilis strains QST30002 and QST3004 (NRRL B-50421 and NRRLB-50455), and Bacillus subtilis strain QST30002 and QST3004 (NRRL B-50421 and NRRLB-50455). 713, Bacillus subtilis strain DSM17231, Bacillus subtilis strain KAS-001, Bacillus subtilis strain KAS-006, Bacillus subtilis strain KAS-009, Bacillus subtilis strain KAS-010, Bacillus subtilis strain KAS-011 and Bacillus subtilis strain CCT0089), Bacillus cyclosporus, Bacillus firmus (such as Bacillus firmus strain 1-1582 (Votivo and Nortica;Bayer AG), Bacillus thuringiensis (e.g., Bacillus thuringiensis subsp. mellonella strain SDS-502, Bacillus thuringiensis subsp. kustak VBTS 2546, Bacillus thuringiensis subsp. kustak VBTS 2477 quadruple enterotoxin-deficient mutant), Bacillus cereus (e.g., Bacillus cereus BP01), simple pure Bacillus (e.g., simple pure Bacillus strains 03WN13, 03WN23, and 03WN25), Bacillus mycoides (e.g., Bacillus mycoides isolate BmJ NRRL B-30890), Bacillus arguta, Bacillus flexus, Bacillus niger (Bacillus niger), Bacillus niger, ... nealsonii), Bacillus sphaericus, Bacillus valerianus (such as Bacillus valerianus strain KAS-003), Bacillus methylotrophic (such as Bacillus methylotrophic strain KAS-002, Bacillus methylotrophic strain KAS-005, Bacillus methylotrophic strain KAS-008, Bacillus methylotrophic strain KAS-012, Bacillus methylotrophic strain KAS-013 and Bacillus methylotrophic strain KAS-014), Bacillus lentis, Bacillus saffron and Bacillus atrophaeus (such as Bacillus atrophaeus strain KAS-004) species; bacteria from the genus Lysinibacillus, in particular bacteria from the species Lysinibacillus sphaericus; bacteria from the genus Microbacterium, in particular bacteria from the species Microbacterium aurantiacus; bacteria from the genus Paenibacillus, in particular bacteria selected from the group consisting of Paenibacillus polymyxa and Paenibacillus dust; or bacteria from the genus Streptomyces, in particular bacteria from the species Streptomyces K61. ;

[0062] In a more specific embodiment, the Gram-positive bacterium is a bacterium from the genus Bacillus, in particular a bacterium selected from the group consisting of: Bacillus itcheniformis, Bacillus megaterium (e.g., Bacillus megaterium strain CCT0536), Bacillus pumilus (e.g., Bacillus pumilus strain GB34 (YieldShield; Bayer), Bacillus pumilus strain QST2808 (Sonata; Bayer), and Bacillus pumilus strain BU F-33), Bacillus licheniformis (e.g., Bacillus licheniformis strain SB3086 (EcoGuard; Novozymes) and Bacillus licheniformis strain DSM17236), Bacillus vegetable, Bacillus deserticola, Bacillus subtilis (e.g., Bacillus subtilis strain GB03 (Kodiak; Bayer), MBI 600 (Subtilex; Becker Underwood), and Bacillus licheniformis strain DSM17236. Underwood) and QST713 (Serenade; Bayer AG), Bacillus subtilis strain GB122 plus, Bacillus subtilis strain EB120, Bacillus subtilis strain J-P13, Bacillus subtilis FB17, Bacillus subtilis strains QST30002 and QST3004 (NRRL B-50421 and NRRLB-50455), sandpaper mutants of Bacillus subtilis strains QST30002 and QST3004 (NRRL B-50421 and NRRLB-50455), Bacillus subtilis strain QST 713, Bacillus subtilis strain DSM 17231, Bacillus subtilis strain KAS-001, Bacillus subtilis strain KAS-006, Bacillus subtilis strain KAS-009, Bacillus subtilis strain KAS-010, Bacillus subtilis strain KAS-011 and Bacillus subtilis strain CCT0089), Bacillus cyclosporus, Bacillus firmus (such as Bacillus firmus strain 1-1582 (Votivo and Nortica;Bayer AG), Bacillus thuringiensis (e.g., Bacillus thuringiensis subsp. mellonella strain SDS-502, Bacillus thuringiensis subsp. kustakii VBTS2546, Bacillus thuringiensis subsp. kustakii strain VBTS2477 quadruple enterotoxin-deficient mutant), Bacillus cereus (e.g., Bacillus cereus BP01), Bacillus simplex (e.g., Bacillus simplex strains 03WN13, 03WN23, and 03WN25), Bacillus mycoides (e.g., Bacillus mycoides isolate BmJ NRRL Bacillus aegypti, Bacillus flexus, Bacillus niger, Bacillus sphaericus, Bacillus valerianus (e.g., Bacillus valerianus strain KAS-003), Bacillus methylotrophic (e.g., Bacillus methylotrophic strain KAS-002, Bacillus methylotrophic strain KAS-005, Bacillus methylotrophic strain KAS-008, Bacillus methylotrophic strain KAS-012, Bacillus methylotrophic strain KAS-013, and Bacillus methylotrophic strain KAS-014), Bacillus lentis, Bacillus saffron, and Bacillus atrophaeus (e.g., Bacillus atrophaeus strain KAS-004).

[0063] In more specific embodiments, the Gram-positive bacteria are bacteria from the species Bacillus subtilis, Bacillus thuringiensis or Bacillus megaterium. In still further specific embodiments, the Gram-positive bacteria are Bacillus subtilis CCT 0089, Bacillus thuringiensis CCT 2335 or Bacillus megaterium CCT 0536.

[0064] According to an embodiment, the bacteria according to the present invention are selected from Gram-negative bacteria.

[0065] Gram-negative bacteria are well known to the skilled person and include bacteria from the genera Acetobacter, Achromobacter, Actinobacter, Agrobacterium, Rhizobium, Azospirillum, Azotobacter, Bordetella, Bradyrhizobium, Brucella, Burkholderia, Campylobacter, Carbophilus, Chelating Bacterium, Chryseobacterium, Citrobacter, Delftia, Enterobacter, Erwinia, Escherichia, Flavobacterium, Francisella, Flatella, Gluconobacter, Helicobacter, Haemophilus, Kalstia, Klebsiella, Legionella, Mesorhizobium, Moraxella, Neisseria, Pantoea, Pasteurella, Leaf Bacterium, Proteus, Pseudomonas, Rhizobium, Salmonella, Serratia, Shigella, Sinorhizobium, Treponema, Vibrio, Xanthomonas and Yersinia.

[0066] In specific embodiments, the Gram-negative bacteria are selected from the group consisting of Acetobacter, Achromobacter, Agrobacterium, Rhizobium, Azospirillum, Azotobacter, Bradyrhizobium, Carbophila, Chelating Bacterium, Delftia, Erwinia, Flavobacterium, Flatowia, Gluconobacter, Mesorhizobium, Neisseria, Pantoea, Leaf Bacterium, Pseudomonas, Rhizobium, Serratia, Sinorhizobium, and Xanthomonas bacteria.

[0067] In a specific embodiment, the Gram-negative bacteria are bacteria from the genus Acetobacter, in particular bacteria from the species Acetobacter xylinum; bacteria from the genus Agrobacterium, in particular bacteria selected from the group consisting of: Agrobacterium radiobacterium (such as Agrobacterium radiobacterium strain K84 and Agrobacterium radiobacterium strain CCT 4774), Agrobacterium rhizogenes, Agrobacterium rubus and Agrobacterium tumefaciens species; bacteria from the genus Azospirillum, in particular bacteria selected from the group consisting of: Azospirillum brasiliensis, Azospirillum doebereinerae, Azospirillum halopraeferens, Azospirillum canadense, Azospirillum oryzae and Azospirillum lipogenes species; bacteria from the genus Azotobacter, in particular bacteria selected from the group consisting of: Azotobacter rotundifolia, Azotobacter vinelandii and Azotobacter salinestris species; bacteria from the genus Bradyrhizobium, in particular bacteria selected from the group consisting of: Bradyrhizobium peanut arachidis), beet Bradyrhizobium, incense burner plate Bradyrhizobium, golden brooding rhizobium (Bradyrhizobium cytisi), Daqing bradyrhizobium soybean rhizobium, denitrifying Bradyrhizobium (Bradyrhizobium denitrificans), legume symbiotic nitrogen-fixing rhizobia, Elmeri Bradyrhizobium, Bradyrhizobium embrapense, Gemu Bradyrhizobium (Bradyrhizobium erythrophlei), Ironwood Bradyrhizobium (Bradyrhizobium ferriligni), Ganzhou Bradyrhizobium (Bradyrhizobium ganzhouense), Guangdong Bradyrhizobium (Bradyrhizobium guangdongense), Huanghuaihai Bradyrhizobium (Bradyrhizobium huanghuaihaiense), Bradyrhizobium icense, Inca Bradyrhizobium, Bradyrhizobium iriomotense, Bradyrhizobium iriomotense (such as Bradyrhizobium iriomotense strain USDA110, B. japonicum bv. genistearum, B. japonicum bv. glycinearum and Bradyrhizobium iriomotense strain CCT 4065), Bradyrhizobium jicamae, Bradyrhizobium kavangense, Bradyrhizobium lentil (Bradyrhizobiumlablabi), Bradyrhizobium liaoningense, Bradyrhizobium lupine, Bradyrhizobium manausense, Bradyrhizobium neotropicale, Bradyrhizobium oligotrophicum, Bradyrhizobium ottawaense, Bradyrhizobium pachyrhizi, Bradyrhizobiumpaxllaeri, Bradyrhizobium retamae, Bradyrhizobium rifense, Bradyrhizobium stylosanthis, Bradyrhizobium subterraneum, Bradyrhizobium tropiciagri, Bradyrhizobium valentinum, Bradyrhizobium viridifuturi and Bradyrhizobium species; bacteria from the genus Delftia, in particular bacteria from the species Acidovorax delftii; bacteria from the genus Frattoia, in particular bacteria from the species Frateuria aurantiaca; bacteria from the genus Gluconobacter, in particular bacteria from the species Gluconobacter diazotrophicus; bacteria from the genus Mesorhizobium, in particular bacteria from the species Mesorhizobium cicero; bacteria from the genus Pseudomonas, in particular bacteria selected from the group consisting of: Pseudomonas putida, Pseudomonas fluorescens, Pseudomonas protegens, Pseudomonas chlororaphis, Pseudomonas aurantiaca, Pseudomonas mendocina and Pseudomonas rathonis species; bacteria from the genus Rhizobium, in particular bacteria selected from the group consisting of: Rhizobium leguminosarum, Rhizobium neinergoniae, Rhizobium bangladeshense, Rhizobium binae, Rhizobium gallicae, Rhizobium hainanensis, Rhizobium cyanobacteria, Rhizobium lentis, Rhizobium loessii, Rhizobium portugalensis, Rhizobium phaseolus and Rhizobium lupine species; bacteria from the genus Sinorhizobium, in particular bacteria from the species Sinorhizobium meliloti.

[0068] In a more specific embodiment, the Gram-negative bacterium is a bacterium from the genus Agrobacterium, in particular a bacterium selected from the group consisting of: Agrobacterium radiobacterium (such as Agrobacterium radiobacterium strain K84 and Agrobacterium radiobacterium strain CCT 4774), Agrobacterium rhizogenes, Agrobacterium rubus and Agrobacterium tumefaciens species; or a bacterium from the genus Bradyrhizobium, in particular a bacterium selected from the group consisting of: Bradyrhizobium arachidis, Bradyrhizobium canariense, Bradyrhizobium cytisi, Bradyrhizobium daqingensis, Bradyrhizobium denitrificans, Bradyrhizobium diazoefficiens, Bradyrhizobium elsdenii, Bradyrhizobium embrapense, Bradyrhizobium ge erythrophlei), Bradyrhizobium ferriligni, Bradyrhizobium ganzhouense, Bradyrhizobium guangdongense, Bradyrhizobium huanghuaihaiense, Bradyrhizobium icense, Bradyrhizobium inca, Bradyrhizobium iriomotense, bradyrhizobia of soybean (such as bradyrhizobium of soybean strain USDA110, B. japonicum bv. genistearum, B. japonicum bv.glycinearum and Bradyrhizobium strain CCT 4065), Bradyrhizobium jicamae, Bradyrhizobium kavangense, Bradyrhizobium lablabi, Bradyrhizobium liaoningense, Bradyrhizobium lupine, Bradyrhizobium manausense, Bradyrhizobium neotropicale, Bradyrhizobium oligotrophicum, Bradyrhizobium ottawaense, Bradyrhizobium pachyrhizi, Bradyrhizobium umpaxllaeri, Bradyrhizobium retamae, Bradyrhizobium rifense, Bradyrhizobiumstylosanthis, Bradyrhizobium subterraneum, Bradyrhizobium tropiciagri, Bradyrhizobium valentinum, Bradyrhizobium viridifuturi, and Bradyrhizobium species.

[0069] In more specific embodiments, the Gram-negative bacterium is a bacterium from the species Agrobacterium radiobacterium, Bradyrhizobium japonicum, or Pseudomonas putida. In still more specific embodiments, the Gram-negative bacterium is Agrobacterium radiobacterium strain CCT 4774, Bradyrhizobium japonicum strain CCT 4065, or Pseudomonas putida CCT 5357.

[0070] According to any of the embodiments of the present invention, the microorganism can be, for example, a bacterium selected from the species Bacillus subtilis, Bacillus megaterium, Bacillus thuringiensis, Agrobacterium radiobacterium, Bradyrhizobium japonicum, or Pseudomonas putida.

[0071] According to another embodiment, the microorganism is a fungus, in particular a unicellular fungus.

[0072] Fungi are well known to those skilled in the art and include ascomycetes, glomerates and basidiomycetes. In a specific embodiment, the fungi are selected from the phylum Ascomycetes, in particular from the group consisting of: Trichoderma, Metarhizium, Beauveria, Lecanopus, Pseudomonas, Gliocladium, Coccidioides, Fusarium, Arthrospora, Penicillium, Aspergillus, Ampelomyces, Conchoderma, Atractyloderma and Candida; from the phylum Glomeromycetes, in particular from the group consisting of Glomeromycetes and Pseudomonas; and / or from the phylum Basidiomycetes, in particular from the group consisting of Phlebiopsis and Rhizoctonia.

[0073] In a specific embodiment, the fungus is a fungus from the genus Trichoderma, in particular a fungus selected from the group consisting of: Trichoderma viride, Trichoderma amurensis, Trichoderma viride, Trichoderma harzianum, Trichoderma hooked, Trichoderma spinulosa, Trichoderma koningii, Trichoderma longibotium, Trichoderma oospore, Trichoderma paucisporum, Trichoderma songyi, Trichoderma theobroma and Trichoderma gaimsii species; a fungus from the genus Metarhizium, in particular a fungus selected from the group consisting of: Metarhizium anisopliae, Metarhizium macrosporum, Metarhizium brown and Metarhizium yellow green species; a fungus from the genus Beauveria, in particular a fungus from the species Beauveria bassiana; a fungus from the genus Lecanopus, in particular a fungus selected from the group consisting of Verticillium lecanii and Lecanopus lecanopus species; a fungus from the genus Purpureocillium, in particular a fungus from the species Purpureocillium lilacinum; a fungus from the genus Glechoma, in particular The present invention also provides a kind of fungus from the genus Fusarium, in particular a fungus from the species of Gliocladium fumosum; a fungus from the genus Fusarium, in particular a fungus from the species of Fusarium; a fungus from the genus Arthrospora, in particular a fungus from the species of Arthrospora digitatum; a fungus from the genus Penicillium, in particular a fungus selected from the group consisting of Penicillium bilairea and Penicillium digitatum; a fungus from the genus Aspergillus, in particular a fungus selected from the group consisting of Aspergillus awamori and Aspergillus niger; a fungus from the genus Ampelomyces, in particular a fungus from the species of Ampelomyces; a fungus from the genus Coniothyrium, in particular a fungus from the group consisting of Coniothyrium microphylla. minitans); a fungus from the genus Aureobasidium, in particular a fungus from the species Aureobasidium; a fungus from the genus Candida, in particular a fungus from the species Candida oleophila; a fungus from the genus Glomus, in particular a fungus selected from the group consisting of Glomus iranicum and Glomus mosseae species; a fungus from the genus Rhizophagus, in particular a fungus from the species Rhizophagus irregularis; a fungus from the genus Phlebiopsis, in particular a fungus from the species Macrocortisone; or a fungus from the genus Rhizoctonia, in particular a fungus from the species Rhizoctonia solani.

[0074] In a more specific embodiment, the fungus is a fungus from the species Aspergillus niger, Trichoderma harzianum or Beauveria bassiana. In still more specific embodiments, the fungus is Aspergillus niger ATCC 16404, Trichoderma harzianum CCT 4790 or Beauveria bassiana ATCC 7159 / DSM 1344.

[0075] According to any of the embodiments of the present invention, the microorganism can be, for example, a bacterium selected from the species Bacillus subtilis, Bacillus megaterium, Bacillus thuringiensis, Agrobacterium radiobacterium, Bradyrhizobium japonicum, or Pseudomonas putida, or a fungus selected from the species Aspergillus niger, Trichoderma harzianum, or Beauveria bassiana, such as those described previously.

[0076] The amount of microorganism to be used may vary depending on the microorganism and may also depend on the seed to be treated. In one embodiment of the present invention, the microorganism is used in an amount ranging from 1.10 4 to 1.10 15 The amount of CFU / quintal seeds was used.

[0077] The present invention also relates to a method for maintaining or increasing the growth rate of microorganisms, in particular bacteria, comprising the step of contacting at least one seed with guar (guar) gum as defined above.

[0078] According to a preferred embodiment, the method is carried out in a liquid medium. Thus, preferably, the method comprises the step of contacting at least one seed with guar gum as defined above in liquid form or with a liquid composition comprising guar gum as defined above.

[0079] The present invention also relates to the use of microorganisms, in particular bacteria, and guar gum as defined above as plant biostimulants. Thus, the present invention relates to the combined use of said microorganisms, in particular bacteria, and guar gum. It has been shown that the combination of said microorganisms, in particular bacteria, and guar gum imparts plant biostimulant activity.

[0080] The present invention also relates to a biostimulant composition comprising at least one microorganism, in particular a bacterium, and at least guar (guar) gum as defined above.

[0081] According to any of the embodiments of the present invention, the microorganism is combined with guar gum in the following ratio: microorganism: guar gum ranges from 1.10 4 to 1.10 15 , for example, ranging from 1.10 4 to 1.10 12 , for example, ranging from 1.10 4 to 1.10 11 CFU / g, for example, ranges from 1.10 4 to 5.10 10 CFU / g, for example, ranges from 1.10 5 to 1.10 10CFU / g. For example, microorganisms and guar gum can be combined in the following ratios: microorganism: guar gum ranges from 1.10 8 to 1.10 12 .

[0082] Preferably, the biostimulant composition is in liquid form.

[0083] The present invention also relates to a kit comprising at least one microorganism, in particular a bacterium, and at least guar (guar) gum as defined above, said kit preferably being used as a plant biostimulant.

[0084] Therefore, the present invention also relates to the use of the above-mentioned kit as a plant biostimulant.

[0085] The present invention also relates to a seed coated with the biostimulant composition as defined above.

[0086] In one embodiment, the seed is a crop or plant species including, but not limited to, corn (Zea mays), Brassica species (e.g., B. napus, B. rapa, B. juncea), alfalfa (Medicagosativa), rice (Oryza sativa), rye (Secale cereale), milo (Sorghum bicolor, Sorghum vulgare), millet (e.g., pearl millet (Pennisetum glaucum), broomcorn millet (Panicum miliaceum), millet (Setaria italica), finger millet (Eleusine coracana)), sunflower (Helianthus annuus), safflower (Carthamus tinctorius), wheat (Triticum aestivum), soybean (Glycine max), tobacco (Nicotiana tabacum), potato (Solanum tuberosum), peanut (Arachis hypogaea), cotton (Gossypium barbadense, Gossypium hirsutum), sweet potato (Ipomoea batatus), cassava (Manihotesculenta), coffee (Cofea spp.), coconut (Cocos nucifera), pineapple (Ananas comosus), citrus (Citrus spp.), cocoa (Theobroma cacao), tea (Camellia sinensis), banana (Musas spp.), avocado (Persea americana), fig (Ficus casica), pomegranate (Psidium guajava), mango (Mangifera indica), olive (Olea europaea), papaya (Carica papaya), cashew (Anacardium occidentale), macadamia (Macadamia integrifolia), almond (Prunus amygdalus), sugar beet (Beta vulgaris), sugarcane (Saccharum officinale). spp.), oats, barley, vegetables, ornamentals, woody plants such as coniferous and deciduous trees, Cucurbita, pumpkin, summer squash, apples, pears, quince, melons, plums, cherries, peaches, nectarines, apricots, strawberries, grapes, raspberries, blackberries, soybeans, milo, sugarcane, rapeseed, clover, carrots, and Arabidopsis thaliana.

[0087] In one embodiment, the seed is of any vegetable species including, but not limited to, tomatoes (Lycopersicon esculentum), lettuce (e.g., Lactuca sativa), green beans (Phaseolus vulgaris), lima beans (Phaseolus limensis), peas (Lathyrus spp.), cauliflower, broccoli, turnips, radishes, spinach, asparagus, onions, garlic, peppers, celery, and members of the genus Cucumber (e.g., cucumber (C. sativus), cantaloupe (C. cantalupensis), and cantaloupe (C. melo).

[0088] In one embodiment, the seed is of any ornamental plant species including, but not limited to, hydrangea (Macrophylla hydrangea), hibiscus (Hibiscus rosasanensis), morning glory (Petunia hybrida), rose (Rosa spp.), azalea (Rhododendron spp.), tulip (Tulipa spp.), daffodil (Narcissus spp.), carnation (Dianthus caryophyllus), poinsettia (Euphorbia pulcherrima), and chrysanthemum.

[0089] In one embodiment, the seed is any conifer species, including but not limited to conifers such as loblolly pine (Pinus taeda), slash pine (Pinus elliotii), jack pine (Pinus ponderosa), lodgepole pine (Pinus contorta), and Monterey pine (Pinus radiata), Douglas fir (Pseudotsugamenziesii); western hemlock (Tsuga canadensis); Sitka spruce (Picea glauca); redwood (Sequoia sempervirens); firs such as silver fir (Abies amabilis) and balsam fir (Abies balsamea); and cedars such as western redwood (Thuja plicata) and Alaskan yellow fir (Chamaecyparis nootkatensis).

[0090] In one embodiment, the seed is any legume species, and these legume species include but are not limited to beans and peas.Beans include guar, locust bean, fenugreek, soybean, vegetable bean, cowpea, mung bean, lima bean, broad bean, haricot bean, chickpea, pea, Aconitum spp., broad bean, kidney bean, lentil, dry kidney bean etc.Leguminous plant includes but is not limited to, Arachis (for example, peanut), Vicia (for example, crown flower, hairy vetch, red bean, mung bean and chickpea), Lupin (for example, lupin), Clover, Phaseolus (for example, common kidney bean and lima bean), Pisum (for example, broad bean), Melilotus (for example, clover), Medicago (for example, alfalfa), Lotus (for example, clover), Lens (lens) (for example, Lens) and Amorpha fruticosa. Typical forage and turf grasses for use in the methods described herein include, but are not limited to, alfalfa, sedge, tall fescue, ryegrass, creeping bentgrass, alfalfa, lotus root, clover, pennywort species, lotononis bainessii, sainfoin and chaff. Other grass species include barley, wheat, oats, rye, sedge, chinensis, sorghum or turf grass plants.

[0091] In another embodiment, the seed is selected from the group consisting of crops or vegetables: corn, wheat, sorghum, soybean, tomato, cauliflower, radish, cabbage, rapeseed, lettuce, ryegrass, grass, rice, cotton, sunflower, and the like. In another embodiment, the seed is selected from the group consisting of corn, wheat, barley, rice, peas, oats, soybean, sunflower, alfalfa, sorghum, rapeseed, sugar beet, cotton, tobacco, forage crops, linseed, grass, vegetables, fruit, and sunflower seeds.

[0092] It should be understood that the term "seed" or "rice seedling" is not limited to species or seeds of a specific or concrete type. The term "seed" or "rice seedling" can refer to seeds from a single plant species, from a seed mixture of multiple plant species, or from a seed blend of different strains in a plant species. In one embodiment, crop seeds include but are not limited to rice, corn, wheat, barley, oats, soybeans, cotton, sunflower, alfalfa, sorghum, rapeseed, sugar beet, tomato, beans, carrots, tobacco, or flower seeds.

[0093] The following examples are included to illustrate embodiments of the invention, but are not limited to the examples described.

[0094] Examples

[0095] Example 1:

[0096] The following materials were used in the experiments:

[0097] Guar gum: Guar (Sydney guar) gum available from Solvay (supplied as a powder)

[0098] Bacterial strains were obtained from the Tropical Culture Collection of the André Tosello Foundation, Brazil.

[0099] Bacillus subtilis CCT 0089

[0100] Bacillus megaterium CCT 0536

[0101] ●Agrobacterium radioactiveis CCT 4774

[0102] ● Bradyrhizobium sojae CCT 4065

[0103] All strains were stored at −80 °C in appropriate culture medium containing 15% glycerol.

[0104] Two different culture media were used in the experiments:

[0105] NA medium containing the following per liter: 3 g meat extract, 5 g peptone, and 15 g agar (for solid media only)

[0106] ●NA medium containing the following per liter: 0.5 g potassium dihydrogen phosphate, 0.2 g magnesium sulfate; 0.1 g sodium chloride; 0.5 g yeast extract; 10 g mannitol (for inoculum and solid media only); 5 mL of 5% bromothymol blue solution and 15 g agar (solid media only).

[0107] For the strains Bacillus subtilis, Bacillus megaterium, and Agrobacterium radiobacterium, NA medium was used. For the strain Bradyrhizobium japonicum, YMA medium was used. These media were selected according to the strain supplier.

[0108] A 250 mL shake flask containing 100 mL of NA or YMA medium was inoculated with 1 mL of the stock culture and cultured at 30°C and 150 rpm for 72 hours.

[0109] For each strain, 10 mL of the reactivated culture medium was then transferred to a 250 mL shake flask containing 100 mL of the same culture medium, guar gum powder was added (0.7 wt% of the culture medium), and cultured at 30° C., 150 rpm for 96 hours. An experiment without the addition of guar gum powder was also performed for each strain as a control.

[0110] After 0 h, 24 h, 48 h, 72 h and 96 h of incubation, 100 μL samples were taken for each experiment. These samples were diluted (the dilution varied depending on the growth of the strain, ranging from 1 x 10 -5 to 1x 10 -15) and plate the dilutions onto solid NA or YMA medium. The plates were incubated at 30°C until colonies appeared. After incubation, the number of colonies present in each dilution was counted and used to assess bacterial growth.

[0111] To determine the bacterial growth rate, construct a log 10 A graph of (number of colonies) versus incubation time. The straight line in this graph represents the exponential phase of bacterial growth, and the angular coefficient represents the bacterial growth rate (μ).

[0112] The μ value was used to compare all experiments and to evaluate the effect of guar gum addition on bacterial growth.

[0113] Example 1a

[0114] In the first set of experiments, the ratio of microorganisms to guar gum was equal to 1.00 x 10 6 CFU / g. Table 1a summarizes the bacterial growth rates (μ) obtained from different experiments:

[0115] composition <![CDATA[Bacterial growth rate (h -1 )]]> Bacillus subtilis CCT 0089 0.0647 Bacillus subtilis CCT 0089 + guar gum 0.0657 Bacillus megaterium CCT 0536 0.0605 Bacillus megaterium CCT 0536 + guar gum 0.0878 Agrobacterium radiobacterium CCT 4774 + guar gum 0.0509 Agrobacterium radioactiveis CCT 4774 0.0681 Bradyrhizobium sojae CCT 4065 0.0891 Bradyrhizobium sojae CCT 4065 + guar gum 0.0939

[0116] Table 1a

[0117] For these four strains, higher bacterial growth rate values were obtained in the presence of guar gum. The addition of guar gum allowed an increase in the growth rate of these different bacterial strains. The relative increase in bacterial growth rate with the addition of guar gum compared to the control for each strain is reported in Table 2a. For two Gram-positive bacteria (Bacillus subtilis and Bacillus megaterium), increases in bacterial growth rate of between 2% and 45% were observed, while for two Gram-negative bacteria (Bradyrhizobium japonicum and Agrobacterium radiobacterium), relative increases of between 5% and 34% were observed.

[0118] strain Relative increase in bacterial growth rate with guar gum addition Bacillus subtilis CCT 0089 2％ Bacillus megaterium CCT 0536 45％ Agrobacterium radioactiveis CCT 4774 34％ Bradyrhizobium sojae CCT 4065 5％

[0119] Table 2a

[0120] Example 1b

[0121] Another set of experiments was conducted in which the ratio of microorganisms to guar gum was equal to 1.0 x 10 10 CFU / g.

[0122] Table 1b summarizes the bacterial growth rates (μ) obtained from different experiments:

[0123] composition <![CDATA[Bacterial growth rate (h -1 )]]> Bacillus subtilis CCT 0089 0.0862 Bacillus subtilis CCT 0089 + guar gum 0.1172 Bacillus megaterium CCT 0536 0.0835 Bacillus megaterium CCT 0536 + guar gum 0.0912 Agrobacterium radioactiveis CCT 4774 0.0882 Agrobacterium radiobacterium CCT 4774 + guar gum 0.1102 Bradyrhizobium sojae CCT 4065 0.0915 Bradyrhizobium sojae CCT 4065 + guar gum 0.0897

[0124] Table 1b

[0125] For these four strains, higher or comparable bacterial growth rate values were obtained in the presence of guar gum. For three of the bacterial strains, the addition of guar gum allowed an increase in growth rate. The relative increase in bacterial growth rate with the addition of guar gum compared to the control for each strain is reported in Table 2b. For two Gram-positive bacteria (Bacillus subtilis and Bacillus megaterium), increases in bacterial growth rate of between 9% and 36% were observed, while for Agrobacterium radiobacterium (Gram-negative bacteria), this relative increase was equal to 25%. For Bradyrhizobium japonicum, the addition of guar gum resulted in comparable growth rates compared to the control, thus maintaining the growth rate of the microorganism.

[0126]

[0127]

[0128] Table 2b

[0129] Example 2

[0130] The following materials were used in the experiments:

[0131] Guar gum: Guar (Sydney guar) gum available from Solvay (supplied as a powder)

[0132] All microbial strains were obtained from the Tropical Culture Collection of the André Tosello Foundation, Brazil, some of which have references in the American Type Culture Collection (ATCC).

[0133] Trichoderma harzianum CCT 4790

[0134] Aspergillus niger ATCC 16404

[0135] Beauveria bassiana ATCC 7159 / DSM 1344

[0136] All strains were stored at −80 °C in appropriate culture media containing 20% glycerol.

[0137] The following culture media were used in the experiments:

[0138] Nutrient broth (NA) containing the following per liter: 3 g meat extract, 5 g peptone, and 15 g agar (for solid media only)

[0139] Oatmeal agar (OA) containing the following per liter: 25g oatmeal or oat flour and 15g agar

[0140] Each liter of 2% malt extract agar (MA2) contains the following: 20g malt extract and 15g agar

[0141] Sabouraud dextrose agar (SDA) containing the following per liter: 40 g glucose, 10 g peptone, and 20 g agar

[0142] According to the supplier's recommendations, media SDA, OA, and MA2 were used for the reactivation of strains Aspergillus niger, Trichoderma harzianum, and Beauveria bassiana, respectively.

[0143] For experiments with guar gum, only NA medium was used.

[0144] Reactivation of microorganisms:

[0145] Petri dishes containing 20 mL of SDA, OA, or MA2 medium were used for reactivation of Aspergillus niger, Trichoderma harzianum, and Beauveria bassiana, respectively.

[0146] The stock culture was used to inoculate solid culture medium of each strain, and the petri dishes were incubated at 25°C until fully grown.

[0147] Cultured with guar gum:

[0148] Fungal spores were recovered from the reactivation medium on the Petri dish and a spore solution was prepared.

[0149] 500 μL of spore solution (approximately 1 x 10 10 CFU / mL) were transferred into Erlenmeyer flasks containing 50 mL of culture medium (control and NA medium with guar gum) and cultured at 25° C. Samples were taken at 48 h, 120 h, and 168 h, filtered on filter paper, and cultured at 60° C., and then weighed.

[0150] *Control medium = NA without guar gum

[0151] Growth Assessment:

[0152] The dry biomass recovery after each sample was plotted as dry biomass versus time and a growth curve was obtained.

[0153] Growth rates (μ) were calculated considering only the exponential phase of growth and compared with controls.

[0154] The μ value was used to compare all experiments and evaluate the effect of guar gum addition on fungal growth. Table 3 summarizes the microbial growth rates (μ) obtained in different experiments:

[0155]

[0156]

[0157] Table 3

[0158] For these three strains, higher growth rates were obtained in the presence of guar gum. The addition of guar gum allowed to increase the growth rate of these different fungal strains. The relative increase in fungal growth rate with the addition of guar gum compared to the control for each strain is reported in Table 4. For these three fungal strains, increases in fungal growth rate of between 29% and 550% were observed.

[0159]

[0160] Table 4

[0161] Example 3

[0162] The following materials were used in the experiments:

[0163] Guar gum: Guar (Sydney guar) gum available from Solvay (supplied as a powder)

[0164] Bacterial strains were obtained from the Tropical Culture Collection of the André Tosello Foundation, Brazil.

[0165] Bacillus thuringiensis CCT 2335

[0166] Pseudomonas putida CCT 5357

[0167] All strains were stored at −80 °C in appropriate culture medium containing 15% glycerol.

[0168] Use only one culture medium for both strains

[0169] NA medium containing the following per liter: 3 g meat extract, 5 g peptone, and 15 g agar (for solid media only)

[0170] A 250 mL shake flask containing 100 mL of NA medium (reactivation medium) was inoculated with 1 mL of the stock culture and cultured at 30° C. and 150 rpm for 72 hours.

[0171] Then, 10 mL of this reactivated culture medium was transferred to a 250 mL shake flask containing 100 ml of culture medium, guar gum powder was added and cultured at 30°C, 150 rpm for 96 hours.

[0172] An experiment without the addition of guar gum powder was also performed for each strain as a control.

[0173] After 0 h, 24 h, 48 h, 72 h, and 96 h of incubation, 100 μL samples were taken for each experiment.

[0174] These samples were diluted (dilution varied depending on the growth of the strain, ranging from 1 x 10 -5 to 1x 10 -15) and the dilutions were plated on solid NA medium. The plates were incubated at 30°C until colonies appeared. After incubation, the number of colonies present in each dilution was counted and used to assess bacterial growth.

[0175] To determine the bacterial growth rate, construct a log 10 A graph of (number of colonies) versus incubation time. The straight line in this graph represents the exponential phase of bacterial growth, and the angular coefficient represents the bacterial growth rate (μ).

[0176] The μ value was used to compare all experiments and evaluate the effect of guar gum addition on bacterial growth. For this set of experiments, the ratio of microorganisms to guar gum was equal to 1.0 x 10 5 CFU / g. Table 5 summarizes the bacterial growth rates (μ) obtained from different experiments:

[0177] composition <![CDATA[Bacterial growth rate (h -1 )]]> Bacillus thuringiensis CCT 2335 0.0898 Bacillus thuringiensis CCT 2335 + guar gum 0.1047 Pseudomonas putida CCT 5357 0.1133 Pseudomonas putida CCT 5357 + guar gum 0.1330

[0178] Table 5

[0179] For both strains, higher bacterial growth rate values were obtained in the presence of guar gum. Thus, the addition of guar gum allowed an increase in bacterial growth rate. Table 6 reports the relative increase in bacterial growth rate with the addition of guar gum compared to the control for each strain. For both bacterial strains, an increase in bacterial growth rate of 17% was observed.

[0180]

[0181]

[0182] Table 6.

Claims

1. In vitro use of guar gum for maintaining or increasing the growth rate of microorganisms.

2. Use of guar gum for maintaining or increasing the growth rate of microorganisms on plants, seeds or in soil.

3. The use according to claim 1 or 2, wherein The microorganism is a fungus or a bacterium.

4. The use according to any one of claims 1 to 3, for increasing the growth rate of microorganisms.

5. The use according to any one of claims 1 to 4, wherein These microorganisms are selected from the group consisting of Gram-positive bacteria.

6. The use according to any one of claims 1 to 4, wherein These microorganisms are selected from the group consisting of Gram-negative bacteria.

7. The use according to any one of the preceding claims, wherein The microorganism is combined with the guar gum in the following ratio: microorganism: guar gum ranges from 1.10 4 to 1.10 15 , for example, ranging from 1.10 4 to 1.10 12 , for example, ranging from 1.10 4 to 1.10 11 CFU / g, for example, ranges from 1.10 4 to 5.10 10 CFU / g, for example, ranges from 1.10 5 to 1.10 10 CFU / g.

8. A method for maintaining or increasing the growth rate of microorganisms, in particular bacteria, comprising the step of contacting at least one seed with guar (guar) gum.

9. Use of microorganisms, in particular bacteria, and guar gum as plant biostimulants.

10. The use according to claim 9, wherein The microorganism is combined with the guar gum in the following ratio: microorganism: guar gum ranges from 1.10 4 to 1.10 15 , for example, ranging from 1.10 4 to 1.10 12 , for example, ranging from 1.10 4 to 1.10 11 CFU / g, for example, ranges from 1.10 4 to 5.10 10 CFU / g, for example, ranges from 1.10 5 to 1.10 10 CFU / g.

11. A biostimulant composition comprising at least one microorganism, in particular a bacterium, and at least guar (guar) gum.

12. The biostimulant composition according to claim 11, wherein The microorganism is combined with the guar gum in the following ratio: microorganism: guar gum ranges from 1.10 4 to 1.10 15 , for example, ranging from 1.10 4 to 1.10 12 , for example, ranging from 1.10 4 to 1.10 11 CFU / g, for example, ranges from 1.10 4 to 5.10 10 CFU / g, for example, ranges from 1.10 5 to 1.10 10 CFU / g.

13. A kit comprising at least one microorganism, in particular a bacterium, and at least guar (guar) gum.

14. Use of the kit according to claim 13 as a plant biostimulant.

15. A seed coated with the biostimulant composition according to claim 11 or 12.

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