Novel plant growth promoting bradyrhizobium compositions

Abstract

The present invention relates to the field of sustainable agriculture. In particular, the present invention relates to isolated Bradyrhizobium bacteria having enhanced characteristics, including but not limited to enhanced adaptation to the low and medium root zone temperature for example in North-West Europe.

Description

[0001]SoGo / BRADY / 812 NOVEL PLANT GROWTH PROMOTING BRADYRHIZOBIUM COMPOSITIONS FIELD OF THE INVENTION The present invention relates to the field of sustainable agriculture. Specifically, the invention provides microbial compositions and methods for improving the yield of nitrogen fixing plants. In particular, the present invention relates to isolated Bradyrhizobium bacteria having enhanced characteristics, including but not limited to enhanced adaptation to low and / or medium soil temperatures, for example in North- West Europe. BACKGROUND Soybean (Glycine max) is one of the most important legume crops worldwide producing protein-rich beans (about 40% of the seed) with all essential amino acids for human food and animal feed (Hammond et al 2003 Beans, Oxford Academic Press). The cultivation of soybean in North-West Europe is challenging because the plant is not adapted to the cold and wet environment. In the last decade, extensive breeding programs and field trials with hundreds of early-maturing soybean cultivars have been performed to find genotypes suitable for growth in more temperate regions such as Belgium (Aper et al 2015 Plant Genetic Resources 1; Pannecoucque et al 2018 J Agri Sc 156:3) and Germany (Zimmer et al 2016 Eur J Agron 72). As a result, dozens of soybean cultivars (such as Primus, Bettina and Shouna cv.) have been bred to be adapted to local environmental conditions in terms of tolerance to common fungal pathogens in combination with high seed yields and protein content. However, when grown in reference soils, none of these cultivars meet the bean protein threshold of >42% that has been set by the industry to be eligible for processing for human consumption (Pannecoucque et al 201J Agri Sci 156:3). To guarantee high protein contents in beans, soybean plants need to engage in a symbiotic interaction with bacteria from nitrogen-fixing genera, the so-called rhizobia. This symbiosis results in the formation of root nodules in which the bacterial strains fix atmospheric nitrogen that is subsequently used for plant protein production. Soybean plants can interact with diverse bacterial genera such as Rhizobium, Bradyrhizobium, Ensifer (Sinorhizobium), Azorhizobium, but also (Para)Bulkholderia (Gyaneshwar et al 2011 MPMI 24; Ramirez et al 2019 Microbes Environ 34; Sharaf et al 2019 Microbiome 7). Currently, soybean cultivation in North-West Europe uses commercially available Bradyrhizobium inoculants leading to variable, unsatisfactory results (Pannecoucque et al 2018 J Agri Sc 156:4; Zimmer et al 2016 Eur J Agron 72). These non-endemic bacterial strains are possibly not adapted to the Northern environmental conditions resulting in insufficient nodulation and subsequently inadequate bean protein contents for the processing industry (Alexandre and Oliveira 2013 Crit Rev Microbiol 39; Pannecoucque et al 2018 J Agri Sc 156:3). Especially the low root zone temperature is a major constraint in the establishment of the legume-rhizobia symbiosis (Schmidt et al 2015 Plant Soil 397; Zhang et al 1995 Environ Exp Bot 35). Optimal temperatures for soybean growth and nodule formation are between 25 SoGo / BRADY / 812 and 30°C which is significantly higher than the North-West Europe soil temperatures that ranges from 8 and 15°C at the sowing time (Miransari et al 2013 J Plant Growth Regul 32). Hence, there is a need to identify new plant symbiotic bacteria that are adapted to low root zone temperatures and that promote yield of leguminous crops both quantitatively and / or qualitatively. SUMMARY A trapping experiment was set up in diverse Belgian soils to capture native soybean nodulators. Two of these nitrogen fixing bacteria are disclosed herein and significantly outperform the most closely related Bradyrhizobium strain in terms of nodule induction, chlorophyl production and soybean growth. Therefore, the invention provides in a first aspect, an isolated Bradyrhizobium R-85101 strain having the deposit accession number LMG P-33069 and an isolated Bradyrhizobium R-85108 strain having the deposit accession number LMG P-33070. Also enriched cultures and biologically pure cultures of said Bradyrhizobium strains are provided. In another aspect, a composition comprising said Bradyrhizobium strains or one of said cultures is provided. In one embodiment, the Bradyrhizobium strains are lyophilized, freeze-dried, dried in a form of a powder or present as an aqueous slurry. In another embodiment, said compositions further comprises growth medium appropriate for Bradyrhizobium species and / or a cryoprotectant. The composition may also further comprise an agriculturally compatible carrier. In another aspect a plant seed coated with one of the Bradyrhizobium strains of the invention or a plant seed coated with one of the two Bradyrhizobium strains are provided. In one embodiment, the plant seed is a leguminous plant seed, more particularly a soybean. Given that the Bradyrhizobium strains disclosed in current application are especially useful in the field of agriculture, methods are provided for enhancing growth, yield and / or nitrogen fixation of plants, more particularly of leguminous plants by administration of said Bradyrhizobium strains to said plants. This is equivalent as saying that the use of the Bradyrhizobium strains of the invention, the cultures or compositions comprising it is provided to enhance growth, yield and / or nitrogen fixation of a plant, more particularly a leguminous plant. In one embodiment, said yield refers to the protein content of the seeds, more particularly of soybeans. It is envisaged that the Bradyrhizobium strains of the invention can be administered by several ways, for example but not limited to by coating plant seeds, inoculating the soil or other plant growth supporting media, spraying or irrigating plants. Hence, in one embodiment, the methods comprise the steps of inoculating a plant growth medium with the Bradyrhizobium strains according to the invention or with one of the cultures or compositions comprising it, and growing the leguminous plant in said plant growth medium. In a particular embodiment, the Bradyrhizobium strains, cultures or compositions are applied to the plant growth medium as a powder, as a pellet, as a granule or as a liquid. In other embodiments, the methods comprise the steps of growing plants in an environment that supports plant growth and administering a sprayable formulation to said environment SoGo / BRADY / 812 or to said plant, said formulation comprising the Bradyrhizobium strains of the invention or the cultures or compositions comprising it. DEPOSIT OF BIOLOGICAL MATERIAL Purified cultures of the microbial strains described in present application were deposited by VIB vzw (Rijvisschestraat 120, 9052 Gent, Belgium) at the BCCM (Belgian Coordinated Collections of Micro- Organisms) consortium (BCCM represented by Laboratorium voor Microbiologie – Bacterienverzameling (LMG), Universiteit Gent, K.L. Ledeganckstraat 35, 9000 Gent, Belgium), recognized as an International Depositary Authority by the World Intellectual Property organization since March 1, 1992 and in accordance with the Budapest Treaty as specified in Rule 31(1) EPC for the purpose of patent procedure and the regulations thereunder. The Bradyrhizobium sp. R-85101 strain of current application has been deposited with deposit number LMG P-33069 for which the original deposit has been done on 30 March 2023. The Bradyrhizobium sp. R-85108 strain of current application has been deposited with deposit number LMG P-33070 for which the original deposit has been done on 30 March 2023. FIGURE LEGENDS Figure 1 shows the nodules of which R-85101 and R-85108 were isolated. (a) R-85101 originated from garden 1200, plant B8, nodule N1 and is 3.9 mm in diameter; (b) R-85101 cut in halve showing the red nodule interior; (c) R-85108 originated from garden 590, plant E5, nodule N4 and is 2.4 mm in diameter (left nodule); (d) R-85108 cut in halve showing the red nodule interior. Figure 2 shows the nodule dry weight per plant in pot trials for R-85101 and R-85108 inoculated plants. Non-inoculated mock plants and plants inoculated with the commercial Bradyrhizobium inoculant G49 were used as negative and positive controls, respectively. Five different soybean varieties were used in these experiments, i.e. Glycine max cv. Hermes (Protealis), Acardia (Saaten-Union), Lenka (Prograin), Aurelina (Saatbau Linz) and Gallec (Agroscope / DSP). The right panel of the figure shows the overall effect of R-85101, R85108 and G49 on the five different soybean varieties tested. Figure 3 shows the relative chlorophyll content in the pot trials for R-85101 and R-85108 inoculated plants. Non-inoculated mock plants and plants inoculated with the commercial Bradyrhizobium inoculant G49 were used as negative and positive controls, respectively. Five different soybean varieties were used in these experiments, i.e. Glycine max cv. Hermes (Protealis), Acardia (Saaten-Union), Lenka (Prograin), Aurelina (Saatbau Linz) and Gallec (Agroscope / DSP). SoGo / BRADY / 812 Figure 4 shows the above ground biomass in the pot trials for R-85101 and R-85108 inoculated plants. Non-inoculated mock plants and plants inoculated with the commercial Bradyrhizobium inoculant G49 were used as negative and positive controls, respectively. Five different soybean varieties were used in these experiments, i.e. Glycine max cv. Hermes (Protealis), Acardia (Saaten-Union), Lenka (Prograin), Aurelina (Saatbau Linz) and Gallec (Agroscope / DSP). Figure 5: left panel shows the number of nodules per plant in the field trial performed in Merelbeke in 2022 for R-85101 and R-85108 inoculated plants, right panel shows the dry weight of the nodules / plant.Non-inoculated mock plants and plants inoculated with the commercial Bradyrhizobium inoculant G49 were used as negative and positive controls, respectively. Two soybean varieties were tested, Glycine max cv. Lenka (Prograin) and RGT Shouna (RAGT). Figure 6 shows the chlorophyll content in the field trial performed in Merelbeke in 2022 for R-85101 and R-85108 inoculated plants. Non-inoculated mock plants and plants inoculated with the commercial Bradyrhizobium inoculant G49 were used as negative and positive controls, respectively. Two soybean varieties were tested, Glycine max cv. Lenka (Prograin) and RGT Shouna (RAGT). Figure 7 shows the average yield (kg / ha) at 15% moisture content in the field trial performed in Merelbeke in 2022 for R-85101 and R-85108 inoculated plants. Non-inoculated mock plants and plants inoculated with the commercial Bradyrhizobium inoculant G49 were used as negative and positive controls, respectively. Two soybean varieties were tested, Glycine max cv. Lenka (Prograin) and RGT Shouna (RAGT). Figure 8 shows the protein content (%) in the field trial performed in Merelbeke in 2022 for R-85101 and R-85108 inoculated plants. Non-inoculated mock plants and plants inoculated with the commercial Bradyrhizobium inoculant G49 were used as negative and positive controls, respectively. Two soybean varieties were tested, Glycine max cv. Lenka (Prograin) and RGT Shouna (RAGT). DETAILED DESCRIPTION The massive soybean import by Europe for food and feed production causes a negative socio-economic and environmental impact. Hence, there is an increasing interest in the local production of soy. Various breeding efforts already resulted in varieties that are able to grow in European colder climates. However, to ensure high protein rich beans, it is essential that soy establishes a symbiosis with nitrogen (N2)-fixing SoGo / BRADY / 812 bacteria in their root nodules. Currently, the use of commercial inoculants in Nord-West European soy agriculture has shown to be variable and insufficient for high quality harvests. In order to get efficient nodulation as soon as possible after sowing and thus early in the growing season, it is imperative to find bacterial strains that are adapted to the medium and cold soil temperatures in North-West Europe and that initiate nodulation of soybean roots at the start of the growing season when the temperature of the soils is still low. To solve this problem, the inventors of current application initiated a nodulation trap experiment during which three early-maturing soybean cultivars were grown in natural conditions in over 100 different garden soils. In the majority of these soils, root nodules were found. Genetic analysis revealed a large bacterial richness and diversity amongst Rhizobia and Bradyrhizobia strains present in these different nodules. In current application novel nitrogen fixing bacterial strains are disclosed, more particularly a Bradyrhizobium R-85101 strain and a Bradyrhizobium R-85108 strain. The strains have a high genetic homology to Bradyrhizobium diazoefficiens USDA 110 strain but compared to the publicly available strains, R-85101 and R-85108 have improved growth characteristics when interacting with soybean plants. The strain of the application is able to undergo a nitrogen fixing interaction with a leguminous plant, more particularly with soy. “Nitrogen-fixing interaction” as used herein refers to a plant-bacterial interaction in which atmospheric nitrogen is made available to the plant as a nutrient through the bacterium. Typically, this interaction results in the formation of root nodules containing the bacterium. STRAIN In one aspect of current application, a Bradyrhizobium sp. R-85101 strain is provided comprising a 16S rRNA sequence as depicted in SEQ ID No.1 and a Bradyrhizobium sp. R-85108 is provided comprising a 16S rRNA sequence as depicted in SEQ ID NO: 2. In one embodiment, said Bradyrhizobium strains are nitrogen fixing bacterial strains. In another embodiment, said Bradyrhizobium strains are Bradyrhizobium diazoefficiencs strains, more particularly the Bradyrhizobium diazoefficiens R-85101 strain and the Bradyrhizobium diazoefficiens R-85108 strain. In another embodiment, said strains are isolated strains. The term “isolated” means that the bacterial strains have been removed from their natural environment. “Isolated” thus implies a purification step. However, “isolated” does not necessarily reflect the extent to which the microorganism, more particularly the bacterium has been purified. A bacterial strain of current application is purified at least 2x, at least 5x, at least 10x, at least 50x or at least 100x from the raw material from which it is isolated. As a non-limiting example, if a microorganism is isolated from soil as raw material, the microorganism can be isolated to an extent that its concentration in a given quantity SoGo / BRADY / 812 of purified or partially purified material (e.g. soil) is at least 2x, at least 5x, at least 10x, at least 50x or at least 100x that in the original raw material. In yet another embodiment, said Bradyrhizobium strains improves the nitrogen status and / or nitrogen fixation of a soybean plant that was inoculated with said strain compared to other publicly available Bradyrhizobium strains, more particularly to the commercial Bradyrhizobium strain G49. With “nitrogen status” as used herein it is meant the nitrogen level or nitrogen concentration or nitrogen usage in the inoculated plant. In another aspect of current application bacterial strains are provided with deposit accession numbers LMG P-33069 and LMG P-33070. In one embodiment, said bacterial strains are nitrogen fixing bacterial strains. In another embodiment, said bacterial strains are the Bradyrhizobium sp. R-85101 and Bradyrhizobium sp. R-85108 strains. In another embodiment, said strains are isolated strains. From here on, any of the above bacterial strains will be referred to as the bacterial strains of current application. In another aspect of the application a culture of the bacterial strains of current application is provided. The term “culture” as used herein refers to a population of microorganisms that are propagated on or in media of various kinds. In one embodiment, said culture is an enriched culture of a bacterial strain of current application. This is equivalent as saying that a culture of microorganisms, more particularly a bacterial culture, is provided, wherein said culture is enriched with a bacterial strain of current application (i.e. Bradyrhizobium sp. R-85101 or sp. R-85108 strains) and wherein “enriched” means that the total microbial (or more particularly the total bacterial) population of said culture contains more than 50%, more than 60%, more than 70%, more than 80%, more than 90%, or more than 95% of the isolated bacterial strain of current application. In another embodiment, a biologically pure culture of a bacterial strain of current application is provided. As used herein, “biologically pure” refers to a culture which contains substantially no other microorganisms than the desired strain and thus a culture wherein virtually all of the cells present are of the selected strain. In practice, a culture is defined biologically pure if the culture contains at least more than 96%, at least more than 97%, at least more than 98% or at least more than 99% of a bacterial strain of current application, more particularly of Bradyrhizobium sp. R-85101 with deposit number LMG P- 33069 and Bradyrhizobium sp. R-85108 with deposit number LMG P-33070. When a biologically pure culture contains 100% of the desired microorganism a monoculture is reached. A monoculture thus only contains cells of the selected strain and is the most extreme form of a biologically pure culture. In yet another embodiment, the culture of one of the Bradyrhizobium strains of the application comprises at least 1%, at least 5%, at least 10%, at least 25%, at least 50% or at least 75% living Bradyrhizobium R-85101 or R-85108 bacteria. SoGo / BRADY / 812 In a particular embodiment, the bacterial strains of current application may be lyophilized, freeze-dried or in a form of a dry powder. In another particular embodiment, an aqueous slurry of the bacterial strains of the current application or of any culture herein described comprising the strain is provided, the slurry being optionally dried to a powder at a temperature which does not adversely affect viability of the bacterial strain. COMPOSITIONS In another aspect, a composition is provided comprising a bacterial strain of current application. This is equivalent as saying that the composition comprises an inoculum of a bacterial strain of the application. As used herein, the term “inoculum” is intended to mean any form of bacterial cells, or spores, which is capable of propagating on or in the soil when the conditions of temperature, moisture, etc., are favourable for bacterial growth. A “spore” generally refers to a microorganism in its dormant, protected state. In a particular embodiment, the composition may be in the form of a liquid, a slurry, a wettable powder or a dry powder. In a particular embodiment, a bacterial strain of current application may be lyophilized, freeze-dried or in the form of a dry powder before it is used in the processing of the composition. In another particular embodiment, an aqueous slurry of a bacterial strain of the current application is provided, which is optionally dried to a powder at a temperature which does not adversely affect viability of the bacterial strain. The powder may then be mixed with an agriculturally compatible carrier. In other embodiments, a liquid suspension or slurry of a bacterial strain of the current application may be applied to an absorbent material, e.g. a granular mass, or may be used to coat plant seeds or other plant tissues. Also a powder comprising a bacterial strain of the application is suitable for coating seeds. When used to coat plant seeds, the composition may be applied to the seeds and allowed to dry. In embodiments wherein the composition is a powder (e.g. a wettable powder), a liquid, such as water, may need to be added to the powder before application to a seed. In another embodiment, a composition is provided comprising a bacterial strain of current application further comprising a cryoprotectant and / or growth medium appropriate for Bradyrhizobium species. A “cryoprotectant” as used herein protects the bacteria by preventing the damaging effects of water crystals when cells are frozen, more particularly at -60°C, or -70°C or -80°C or in liquid nitrogen. Non- limiting examples of a cryoprotectant is glycerol and trehalose. In another embodiment, a composition is provided comprising the bacterial strain herein disclosed wherein the bacterial strain is lyophilized, freeze dried or in the form of a dry powder. In one embodiment, the composition can further comprise a preservative. SoGo / BRADY / 812 In another particular embodiment, any of the compositions described herein further comprises an agriculturally compatible carrier. Said carrier can be inert (e.g. a detectable agent or label or liquid carrier) or active (e.g. a fertilizer), but should allow the bacterial strain of the application to remain efficacious and viable. An “agriculturally compatible carrier” may be a natural or synthetic, organic or inorganic material with which the active compounds (e.g. a bacterial strain of the current application) are combined to facilitate their application on the plant, a plant part, plant seed or to the plant growth medium. Said “agriculturally compatible carrier” which can be regarded as a vehicle, is generally inert and it must be acceptable in agriculture. Thus, the phrase “agriculturally compatible” denotes a substance that can be used routinely under field conditions without interfering with growers’ planting equipment, and without adversely influencing crop development or the desired ecological balance in a cultivated area. The agriculturally compatible carrier can be solid. Solid carriers can include but are not limited to clays, natural or synthetic silicates, silica, resins, waxes, solid fertilizers, a polymer, a granular mass, perlite, a perlite granule, peat, a peat pellet, soil, vermiculite, charcoal, sugar factory carbonation press mud, rice husk, carboxymethyl cellulose, fine sand, calcium carbonate, flour, alum, a starch, talc, polyvinyl pyrrolidone, or a combination thereof. The agriculturally compatible carrier can be a liquid. In one embodiment, the liquid carrier is water, sugar water, diluted or non-dilute growth medium to culture the bacterial strain of the application. Non-limiting examples of suitable growth media for said bacterial strain include yeast extract mannitol (YEM), yeast mannitol agar (YMA), yeast mannitol broth (YMB). Other non-limited example of liquid carriers can include but are not limited to water, sugar wateralcohols, ketones, petroleum fractions, oils, aromatic or paraffinic hydrocarbons, chlorinated hydrocarbons, liquefied gases or a combination thereof. More particularly, the agriculturally compatible carrier can include a dispersant, a surfactant, an additive, a thickener, an anti-caking agent, residue breakdown, a composting formulation, a granular application, diatomaceous earth, a colouring agent, a stabilizer, a preservative, a polymer, a coating or a combination thereof. The carrier can also be a slurry, optionally comprising a sticking agent capable of sticking the inoculum to the substrate of interest, for example to a plant seed. Non-limiting examples of sticking agents include alginate, mineral oil, syrup, gum arabic, honey, methyl cellulose, milk, wallpaper paste, and combinations thereof. One of the ordinary skills in the art can readily determine the appropriate carrier to be used taking into consideration factors such as a particular bacterial strain, plant to which the inoculum is to be applied, type of soil, climate conditions, whether the inoculum is in liquid, solid or powder form, and the like. The additive can comprise an oil, a gum, a resin, a clay, a polyoxyethylene glycol, a terpene, a viscid organic, a fatty acid ester, a sulfated alcohol, an alkyl sulfonate, a petroleum sulfonate, an alcohol sulfate, a sodium alkyl butane diamate, a polyester of sodium thiobutant dioate, a benzene acetonitrile SoGo / BRADY / 812 derivative, a proteinaceous material, or a combination thereof. The proteinaceous material can include a milk product, wheat flour, soybean meal, blood, albumin, gelatine, or a combination thereof. The thickener can comprise a long chain alkylsulfonate of polyethylene glycol, polyoxyethylene oleate or a combination thereof. The surfactant can contain a heavy petroleum oil, a heavy petroleum distillate, a polyol fatty acid ester, a polyethoxylated fatty acid ester, an aryl alkyl polyoxyethylene glycol, an alkyl amine acetate, an alkyl aryl sulfonate, a polyhydric alcohol, an alkyl phosphate, or a combination thereof. The anti-caking agent can include a sodium salt such as a sodium sulfite, a sodium sulfate, a sodium salt of monomethyl naphthalene sulfonate, or a combination thereof, or a calcium salt such as calcium carbonate, diatomaceous earth, or a combination thereof. The agriculturally compatible carrier can also include a fertilizer, a micronutrient fertilizer material, an insecticide, a herbicide, a plant growth amendment, a fungicide, a molluscicide, an algicide, a bacterial inoculant, a fungal inoculant, or a combination thereof. Non-limiting examples are provided below. As way of example the bacterial strain of the current application may be mixed with an agriculturally compatible carrier. Non-limiting examples of the above provided composition in practice are soluble powders, wettable granules, dry flowables, aqueous flowables, wettable dispersible granules, emulsifiable concentrates, aqueous suspensions, a fertilizer granule, a sprayable formulation, an agrochemical formulation. Thus, in another embodiment, an agricultural composition comprising the bacterial strain of current application is provided. “Agricultural composition” as used herein refers to a composition for agricultural purposes. Given that the composition is of use to promote plant growth and development, more particularly to promote the quantitative and / or qualitative yield of a leguminous plant, even more particularly to promote nitrogen fixation of a leguminous plant, most particularly to increase the protein content of soybeans, also a plant growth promoting composition is provided. Plant growth promoting refers to a promoting effect on the growth and development of the cultured plant or crop. Said cultured plant or crop is the plant or crop of interest and does not include unwanted plants. As described above, the composition or “plant growth promoting composition” herein provided can include a herbicide, if said herbicide is used to remove unwanted plants or prevent germination of seeds of unwanted plants. The composition, agricultural composition or plant growth promoting composition can also comprise a fertilizer, a micronutrient fertilizer material, an insecticide, a plant growth amendment, a fungicide, a molluscicide, an algicide, a bacterial inoculant, a fungal inoculant, or a combination thereof. In some cases, the fertilizer is a liquid fertilizer. Liquid fertilizer can include without limitation, ammonium sulfate, ammonium nitrate, ammonium sulfate nitrate, ammonium chloride, ammonium bisulfate, ammonium polysulfide, ammonium thiosulfate, aqueous ammonia, anhydrous ammonia, ammonium polyphosphate, aluminum sulfate, calcium nitrate, calcium ammonium nitrate, calcium sulfate, calcined magnesite, calcitic limestone, calcium oxide, hampene (chelated iron), dolomitic limestone, hydrate SoGo / BRADY / 812 lime, calcium carbonate, diammonium phosphate, monoammonium phosphate, potassium nitrate, potassium bicarbonate, monopotassium phosphate, magnesium nitrate, magnesium sulfate, potassium sulfate, potassium chloride, sodium nitrates, magnesian limestone, magnesia, disodium dihydromolybdate, cobalt chlorid hexahydrate, nickel chloride hexahydrate, indole butyric acid, L- tryptophan, urea, urea-formaldehydes, urea ammonium nitrate, sulfur-coated urea, polymer-coated urea, isobutylidene diurea, K2SO4-2MgSO4, kainite, sylvinite, kieserite, Epsom salts, elemental sulfur, marl, ground oyster shells, fish meal, oil cakes, fish manure, blood meal, rock phosphate, super phosphates, slag, bone meal, wood ash, manure, bat guano, peat moss, compost, green sand, cottonseed meal, feather meal, crab meal, fish emulsion or a combination thereof. The micronutrient fertilizer material can comprise boric acid, a borate, a boron frit, copper sulfate, a copper frit, a copper chelate, a sodium tetraborate decahydrate, an iron sulfate, an iron oxide, iron ammonium sulfate, an iron frit, an iron chelate, a manganese sulfate, a manganese oxide, a manganese chelate, a manganese chloride, a manganese frit, a sodium molybdate, molybdic acid, a zinc sulfate, a zinc oxide, a zinc carbonate, a zinc frit, zinc phosphate, a zinc chelate or a combination thereof. In a particular embodiment, said fertilizer or fertilizer material does not comprise insoluble selenium, selenium mineral, soluble selenium or salts thereof. The insecticide can include an organophosphate, a carbamate, a pyrethroid, an acaricide, an alkyl phthalate, boric acid, a borate, a fluoride, sulfur, a haloaromatic substituted urea, a hydrocarbon ester, a biologically-based insecticide, or a combination thereof. The herbicide can comprise a chlorophenoxy compound, a nitrophenolic compound, a nitrocresolic compound, a dipyridyl compound, an acetamide, an aliphatic acide, an anilide, a benzamide, a benzoic acid, a benzoic acid derivative, anisic acid, an anisic acid derivative, a benzonitrile, benzothiadiazinone dioxide, a thiocarbamate, a carmabate, carbanilate, chloropyridinyl, a cyclohexenone derivative, a dinitroaminobenzene derivative, a fluorodinitrotoluidine compound, isoxazolidinone, nicotinic acide, isopropylamine, an isopropulamine derivative, oxadiazolinone, a phosphate, a phthalate, a picolinic acid compound, a triazine, a triazole, a uracil, a urea derivative, endothall, sodium chlorate, or a combination thereof. The fungicide can comprise a substituted benzene, a thiocarbamate, an ethylene bis dithiocarbamate, a thiophthalidamide, a copper compound, an organomercury compound, an organotin compound, a cadmium compound, anilazine, benomyl, cyclohexamide, dodine, etridiazole, iprodione, metlaxyl, thiamimefon, triforine, or a combination thereof. The fungal inoculant can comprise a fungal inoculant of the family Glomeraceae, a fungal inoculant of the family Claroidoglomeraceae, a fungal inoculant of the family Acaulosporaceae, a fungal inoculant of the family Sacculospraceae, a fungal inoculant of the family Entrophosporaceae, a fungal inoculant of the family Pacidsproraceae, a fungal inoculant of the family Diversisporaceae, a fungal inoculant of the family Paraglomeraceae, a fungal inoculant of the family Archaeosporaceae, a fungal inoculant of the family Geosiphonaceae, a fungal SoGo / BRADY / 812 inoculant of the family Ambisporacea, a fungal inoculant of the family Scutellosproaceae, a fungal inoculant of the family Dentiscultataceae, a fungal inoculant of the family Racocetraceae, a fungal inoculant of the phylum Basidiomycota, a fungal inoculant of the phylum Ascomycota, a fungal inoculant of the phylum Zygomycota, a fungal inoculant of the genus Glomus or a combination thereof. The bacterial inoculant can include a bacterial inoculant of the genus Rhizobium, another bacterial inoculant of the genus Bradyrhizobium, bacterial inoculant of the genus Mesorhizobium, bacterial inoculant of the genus Azorhizobium, bacterial inoculant of the genus Allorhizobium, bacterial inoculant of the genus Burkholderia, bacterial inoculant of the genus Sinorhizobium, bacterial inoculant of the genus Kluyvera, bacterial inoculant of the genus Azotobacter, bacterial inoculant of the genus Pseudomonas, bacterial inoculant of the genus Azosprillium, bacterial inoculant of the genus Bacillus, bacterial inoculant of the genus Streptomyces, bacterial inoculant of the genus Paenibacillus, bacterial inoculant of the genus Paracoccus, bacterial inoculant of the genus Enterobacter, bacterial inoculant of the genus Alcaligenes, bacterial inoculant of the genus Mycobacterium, bacterial inoculant of the genus Trichoderma, bacterial inoculant of the genus Gliocladium, bacterial inoculant of the genus Klebsiella, or a combination thereof. Also, the application provides a combination comprising a bacterial strain of current application and at least one microorganism selected from the list consisting of Bacillus subtilis strain 713, Bacillus amyloliquefaciens MBI 600, Bacillus pumillus QST2808, Pseudomonas fluorescens, Trichoderma vireus, Pseudomonas putida, Trichoderma harzianum Rifai strain T22, Penicillium bilaii, Mesorhizobium, Azospirillum, Azotobacter vinelandii and Clostridium pasteurianum. In another embodiment, an agricultural or plant growth promoting composition comprising a bacterial strain of current application and an agriculturally compatible carrier is provided. COATED SEEDS In a next aspect, a plant seed or plant propagule coated with a microbial population comprising a bacterial strain of current application is provided. This is equivalent as saying that a plant seed or plant propagule is provided, wherein said plant seed or propagule having applied to the surface of said seed or of said propagule, a culture, an enriched culture or a biological pure culture of a bacterial strain of current application. A “plant propagule” is any plant material for the purpose of plant propagation. Because of the totipotency of plants, any part of the plant may be used (e.g. a stem cutting, a leaf section, a portion of a root), though it is usually a highly meristematic part such as root and stem ends, buds, tubers, bulbs, rhizome, stolon or any plant part for vegetative reproduction. In sexual reproduction, a propagule is a seed or spore. SoGo / BRADY / 812 A “plant seed coated” or alternatively a “coated seed” as used in this application refers to a plant seed covered with a certain composition. This composition (i.e. the coating composition) can be a water composition or an oil composition or a polymer or any of the above described compositions comprising the bacterial strain of the application. “Coating” includes the simplest covering methods of dipping seeds or plant propagules in a microbial suspension or spraying seeds or propagules with a microbial suspension. In the latter case, the coating compositions are found to be film-forming, i.e. upon contacting with seeds or propagules they form a thin liquid film that adheres to the surface. “Coating” also includes rolling seeds / propagules in or dusting seeds / propagules with or brushing seeds / propagules with a powder comprising microorganisms, to more complex procedures as injecting plant seeds / propagules with a composition comprising microorganism or the use of complex coating layers including one or more adhesive, binder solvent and / or filler components. A person skilled in the art is familiar with a variety of conventional and more advanced methods to coat plants seeds (e.g. US5113619, EP0080999, WO1997036471, EP0010630, WO2006131213, WO2001045489, US4465017, EP2676536 which are here all incorporated as reference). The coating composition can include a number of ingredients, including but not limited to gelatin, a desiccant, water, tallow (e.g. to increase the release rate of any active ingredient in the composition), bulking agents (e.g. clay, vermiculite, perlite and / or bentonite to give more body to the liquid coating composition). Coating compositions which include bulking agents produce more rounded coated seeds. Such coated seeds are generally easier to plant when using mechanical planters. The concentration of the bulking agent can be up to about 50 % of the solids by volume. As way of example of a liquid coating procedure, seeds or propagules are fed into one or more tanks containing the liquid coating composition. The seeds or propagules are transported from the tanks into a drying zone where forced air dries and solidifies the coating applied to the seeds. The seeds or propagules are dipped at least once and preferably at least twice in the liquid coating composition of the present invention. The dried coated seeds or propagules can be sowed or planted using standard sowing or planting machinery or by hand. In the alternative, the coated seeds or propagules can be stored for later application. If the temperature and humidity are relatively high or if prolonged storage is contemplated, it is desirable to place on the surface of the coating an inert material, preferably a powder material, such as, chalk or talcum powder. Such inert material reduces the tendency for the seed to stick together or agglomerate. The coating should cover more than 50%, more than 60%, more than 70%, more than 80%, more than 90, more than 95% of the surface area of the seeds or propagules. In some embodiments, after the coating procedure, the seeds should comprise at least one living cell of an isolated bacterial strain of current application. The coating layer can also consist of one or more components. These components can be additional plant growth promoting microorganisms but can also be fertilizers, biocontrol agents, or pesticides including fungicides, insecticides and herbicides. SoGo / BRADY / 812 Non-limiting examples of these components are provided above. The coating composition can also include protective colloids, adhesives, thickening agents, thixotropic agents, penetrating agents, stabilizing agents, sequestering agents, fertilizers, anti-freeze agents, repellents, color additives, corrosion inhibitors, water-repelling agents, siccatives, UV-stabilizers, pigments, dyes or polymers. In another embodiment, when used as a seed treatment, the bacterial strain of current application is applied at a rate of about 1x10² to about 1x1011cfu / seed or at a rate of about 1x10³ to about 1x1010cfu / seed or at a rate of at least 1x10², at least 1x10³, at least 1x104, at least 1x105, at least 1x106, at least 1x107, at least 1x108, at least 1x109, at least 1x1010or at least 1x1011cfu / seed. In yet another embodiment, for coating purposes seeds are treated with a bacterial solution of at least 1x105cfu of the bacterial strain of current application per ml, at least 1x106cfu of the bacterial strain of current application per ml, at least 1x107cfu of the bacterial strain of current application per ml, at least 1x108cfu of the bacterial strain of current application per ml, at least 1x109cfu of the bacterial strain of current application per ml, at least 1x1010cfu of the bacterial strain of current application per ml or at least 1x1011cfu of the bacterial strain of current application per ml. After the coating procedure, the bacterial strain of current application is present on the seeds in a concentration of between 1x104and 1x107CFU, between 1x105and 5x106CFU per seed or at least 1x105CFU, at least 1x106CFU or at least 1x107CFU per seed. In a particular embodiment, a plant seed refers to a seed of a leguminous plant. A leguminous plant or alternatively phrased a legume is referred in current application as a plant from the family Fabaceae (or Leguminosae). When used as a dry grain, the seed is also called a pulse. Leguminous plants are grown agriculturally, primarily for human consumption, for livestock forage and silage, and as soil-enhancing green manure. Well-known leguminous plants include beans (Phaseolus), soybeans (Glycine max), broad beans (Vicia faba), peas (Pisum sativum), chickpeas (Cicer arietinum), bitter vetch (Vicia ervilia), peanuts (Arachis hypogaea), lentils (Lens culinaris), lupins (Lupinus), mesquite (Prosopis), carob (Ceratonia siliqua), tamarind (Tamarindus indica), alfalfa (Medicago sativa), liquorice (Glycyrrhiza glabra) and clover (Trifolium sp.). In another aspect, a method is provided of treating plant seeds, the method comprises the step of applying to said seeds an inoculum of a bacterial strain of the application. In one embodiment, said treating is coating. In another embodiment, said plant seeds are seeds from a leguminous plant, more particularly soybean. SoGo / BRADY / 812 APPLICATIONS In a next aspect, the use of the Bradyrhizobium R-85101 or R-85108 strains of the application or of a microbial population comprising it or of any of the previously described cultures is provided to increase or improve plant yield, more particularly agricultural yield. “Yield” as used herein, generally refers to a measurable product from a plant, and more particularly to the amount or quality of harvestable plant material or plant-derived product. “Yield” is normally defined as the measurable produce of economic value of a crop. For crop plants, “yield” also means the amount and / or quality of harvested material per hectare or unit of production. Yield may be defined in terms of quantity or quality. The harvested material may vary from crop to crop, for example, it may be seeds, above ground biomass, roots, fruits, fibres, any other part of the plant, or any plant-derived product which is of economic value. The term “yield” also encompasses yield potential, which is the maximum obtainable yield. Yield may be dependent on a number of yield components, which may be monitored by certain parameters. These parameters are well known to persons skilled in the art and vary from crop to crop. The yield can be determined using any convenient method, for example, kilograms of plant product produced per hectare of planting or bushels or pound of plant product produced per acre of planting. The term “yield” also encompasses harvest index, which is the ratio between the harvested biomass over the total amount of biomass. The harvest index is relatively stable under many environmental conditions, and so a robust correlation between plant size and yield is possible. Yield and yield increase (in comparison to a control plant) can be measured in a number of ways, and it is understood that a skilled person will be able to apply the correct meaning in view of the particular embodiments, the particular crop concerned and the specific purpose or application concerned. The terms “enhanced yield” or “improved yield” or “increased yield” can be used interchangeable. As used herein, the term “enhanced yield” means any statistically significant improvement of one or more yield parameters selected from the group consisting of biomass yield, dry biomass yield, aerial dry biomass yield, underground dry biomass yield, fresh-weight biomass yield, aerial fresh-weight biomass yield, underground fresh-weight biomass yield, enhanced yield of harvestable parts, either dry or fresh-weight or both, either aerial or underground or both, enhanced yield of seeds, either dry or fresh-weight or both, either aerial or underground or both, improved nutrient use efficiency, improved seed set and harvest, improved protein content per seed, increased stress tolerance., increased efficiency of nodulation and / or nitrogen fixation, increased efficiency of carbon assimilation, improvement of seedling vigour / early vigour and / or enhanced efficiency of germination (under stressed or non-stressed conditions). For example, yield refers to biomass yield, e.g. to dry weight biomass yield and / or fresh-weight biomass yield. Biomass yield refers to the aerial or underground parts of a plant, depending on the specific SoGo / BRADY / 812 circumstances (test conditions, specific crop of interest, application of interest, and the like). In one embodiment, biomass yield refers to the aerial and underground parts. Biomass yield may be calculated as fresh-weight, dry weight or a moisture adjusted basis. Biomass yield may be calculated on a per plant basis or in relation to a specific area (e.g. biomass yield per acre / square meter / or the like). “Yield” can also refer to seed yield which can be measured by one or more of the following parameters: number of seeds or number of filled seeds (per plant or per area (acre, square meter or the like); seed filling rate (ratio between number of filled seeds and total number of seeds); number of flowers per plant; seed biomass or total seeds weight (per plant or per area (acre, square meter or the like); thousand kernel weight (TKW; extrapolated from the number of filled seeds counted and their total weight; an increase in TKW may be caused by an increased seed size, an increased seed weight, an increased embryo size, and / or an increased endosperm) and protein content of the harvested seeds. Other parameters allowing to measure seed yield are also known in the art. Seed yield may be determined on a dry weight or on a fresh weight basis, or typically on a moisture adjusted basis, e.g. at 15.5 % moisture. For example, the term “increased yield” means that a plant, exhibits an increased growth rate, e.g. in the absence or presence of abiotic environmental stress, compared to the corresponding wild-type plant. An increased growth rate may be reflected inter alia by or confers an increased biomass production of the whole plant, or an increased biomass production of the aerial parts of a plant, or by an increased biomass production of the underground parts of a plant, or by an increased biomass production of parts of a plant, like stems, leaves, blossoms, fruits, and / or seeds. A prolonged growth comprises survival and / or continued growth of the plant, at the moment when the untreated control plant shows visual symptoms of deficiency and / or death. In accordance with the invention, changes in different phenotypic traits may improve yield. For example, and without limitation, parameters such as floral organ development, seed number, seed weight, protein content of the seed, root initiation, root biomass, harvest index, leaf formation, phototropism, apical dominance, and fruit development, are suitable measurements of improved yield. Increased yield includes higher seed yields, higher protein content of the seed, higher fresh matter production, and / or higher dry matter production. Any increase in yield is an improved yield in accordance with the invention. For example, the improvement in yield can comprise a 0.1%, 0.2%, 0.5%, 0.8%, 1%, 3%, 5%, 10%, 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or greater increase in any measured parameter compared to a mock situation. For example, an increase in the seed / acre yield of soy treated with the bacterial strain of the invention, as compared with the seed / acre yield from untreated soy cultivated under the same conditions, is an improved yield in accordance with the invention. Also an increased protein content / seed of soy treated with the bacterial strain of the invention, as compared with the protein SoGo / BRADY / 812 content / seed from untreated soy cultivated under the same conditions, is an improved yield in accordance with the invention. The yield of a plant can depend on the specific plant or crop of interest as well as its intended application (such as food production, feed production, processed food production, biofuel, biogas or alcohol production, or the like) of interest in each particular case. In one embodiment, yield can be calculated as harvest index (see definition above), harvestable parts weight per area (acre, square meter, or the like); and the like. Measurements of plant size in early development, under standardized conditions in a growth chamber or greenhouse, are standard practices to measure potential yield advantages conferred by the presence of plant growth promoting or nitrogen fixing bacteria. When the plant treated with a bacterial strain of the application is a leguminous plant, increased yield means, in one embodiment, increased seed yield. Increased seed yield refers to a statistically significant increase or an at least 0.1%, 0.2%, 0.5%, 0.8%, 1%, 2%, 3%, 4%, 5%, 10%, 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or more increase compared to an untreated but identical leguminous plant. In particular, increased yield for soy plants means increased seed yield, in particular for soy varieties used for feed or food. Non-limiting examples of soy varieties are Primus, Shouna, Bettina, Amarok, Lenka, Artemis and Hermes. Increased seed yield of soy refers in one embodiment to an increased seed size or weight, an increased number of seeds per pod, an increased number of pods per plant, improvement of seed composition or an increased protein content of the seeds. In a particular embodiment, increased protein content means obtaining a protein content of between 35 and 48%, of between 39 and 45%, between 40 and 44%, between 41 and 43% or of least 42% or of least 43% or of least 44%. The protein content of seeds, more particularly of soybeans can be measured by several methods known by the skilled person. The classical method for whole seed protein determination is the complete extraction of whole seed protein followed by nitrogen determination using either the Kjeldahl method (ISO 5683-2) or the Bradford assay based on a protein / nitrogen ratio of 6.25 (e.g. Yu et al 2016 Food Chem 196; James and Aijun et al 2016 Food Chem 194). Hence, the protein content can be calculated according to the formula: protein content = nitrogen content x 6.25. Another non-limiting example of protein measurement is the combination of near infrared (NIR) spectroscopy and the Kjeldahl method. In a nutshell, dry seed material from a collection of samples is first analysed by NIR spectroscopy. Next, in order to calibrate the NIR spectroscopy data, protein content of a selection (e.g. 10%) of the samples covering the spectral variation of the complete set of samples is determined using the Kjeldahl method. Finally, based on the calibrated NIR spectroscopy data the protein content of all samples can be determined (Pannecoucque et al 2018 Eur J Agron 132; Pannecoucque et al 2018 J Agr Sci 156). In a particular embodiment of the SoGo / BRADY / 812 invention, the protein content percentages herein disclosed are determined based on the Kjeldahl method (ISO 5683-2). In another embodiment, increased seed yield of soy refers to an increased harvest of seeds per area, such as acre or hectare (ha). In a particular embodiment, increased seed yield means obtaining a seed yield of between 3.5 and 6 ton / ha, between 4 and 5.5 ton / ha or between 4.5 and 5 ton / ha or of at least 4 ton / ha, at least 4.5 ton / ha, at least 5 ton / h or of at least 5.5 ton / ha. The above described increased or improved yield can be achieved in the absence or presence of stress conditions. The bacterial strain of the application is also provided to be of use to improve the adaptation of plants, more particular leguminous plants to cool growing conditions. More particularly to be of use to increase nitrogen fixation of the treated plant, more particularly leguminous plant in cool growing temperatures. How to measure nitrogen fixation in a plant is known by the person skilled in the art, e.g. as explained in Pannecoucque et al 2018 (Eur J Agron 132). In short, nitrogen (N) derived from the air is measured based on the different ratios of the stable nitrogen isotopes15N:14N in air and soil respectively. In yet another embodiment, the use of a bacterial strain of the application is provided to increase cold tolerance of a plant. This solution is of great agricultural importance as low temperatures often significantly affect plant growth and crop productivity with crop losses as result (Xin and Browse 2001 Plant Cell Environ 23:893-902). Cold tolerance in plants is a very complex trait, involving many different metabolic pathways and cell compartments. Plants respond with changes in their pattern of gene expression and protein products when exposed to low temperatures. Plants differ in their tolerance to cold or chilling (0-17°C) and freezing (< 0°C) temperatures. Plants of tropical and subtropical origins (e.g. soy) are highly sensitive to cold or chilling stress and are injured or killed by non-freezing low temperatures or have a reduced nitrogen fixing capacity. They exhibit various symptoms of chilling injury such as chlorosis, necrosis, or growth retardation. In contrast, plants from temperate climatic regions can be cold or chilling tolerant with variable degree and can be able to grow at such non-freezing cold temperatures. “Cold tolerance” or equivalently “chilling tolerance” or “low temperature tolerance” as used in current application is defined as the ability of a plant to tolerate low temperatures without or with limited injury, damage or yield drop, wherein said low temperatures are non-freezing temperatures. In one embodiment said low temperatures are temperatures between 5 and 20°C or between 8 and 18°C or between 10 and 15°C. In one embodiment, these temperatures are the temperatures of the soil or plant growth medium. Plants or plant roots are exposes to said low temperatures for at least 2h, at least 4h, SoGo / BRADY / 812 at least 6h or at least 8h per day or said low temperatures are reached during at least a part of the day, for example during the night. In particular embodiments, cold tolerance observed in plants that were treated with or were grown from seeds coated with the bacterial strain of current application leads to injury, damage or a drop in yield or nitrogen fixation due to low temperatures which is at least 10%, least 20%, least 30%, least 40%, least 50%, least 60%, least 70%, least 80%, least 90% or 100% less than the injury, damage or a drop in yield or nitrogen fixation observed in plants that were not treated with or were grown from seeds not coated with the bacterial strain of current application. In particular embodiments, the use of a bacterial strain of the application is provided to increase tolerance to non-freezing low temperatures in plants, more particularly leguminous plants, wherein said low temperatures are between 5 and 20°C or between 8 and 18°C or between 10 and 15°C. More particularly, increased tolerance to said non-freezing low temperatures in leguminous plants means increased tolerance of nitrogen fixation to said non-freezing low temperatures in leguminous plants, more particularly in soybean. In a next aspect, a method is provided for enhancing growth, yield and / or cold tolerance of a plant comprising inoculating a plant growth medium with a microbial population, wherein said population comprises the bacterial strain of current application; and growing a plant in said plant growth medium; to enhance growth, yield and / or cold tolerance of said plant. In one embodiment, said yield is seed yield. In another embodiment, said enhancing yield is enhancing the protein content of seeds, more particularly of seeds of a leguminous plant. In one particular embodiment, said cold tolerance is cold tolerance of nitrogen fixation. Also provided is a method for enhancing nodulation or enhancing nitrogen fixation of a leguminous plant comprising inoculating a plant growth medium with a microbial population, wherein said population comprises the bacterial strain of current application and growing a leguminous plant in said plant growth medium to enhance nitrogen fixation of said plant. In one embodiment, said bacterial strains of current application are Bradyrhizobium sp. R-85101 with deposit number LMG P-33069 and Bradyrhizobium sp. R-85108 with deposit number LMG P-33070.. In another embodiment, said leguminous plant is soybean. The term “enhancing nodulation” is defined herein as a statistically significant increase and / or an at least 5%, 10%, 20%, 30%, 40%, 60%, 70%, 80%, 90%, 100% or more increase in the number of nodules per root system, more particular per cm root system or per gram fresh or dry weight of the root system. The term “inoculating” as used herein refers to introducing at least one bacterium into a plant growth medium. By way of example and without the intention to be limiting, said introduction can be performed using a liquid, a powder, a granule, a pellet. “Plant growth medium” is defined as any environment SoGo / BRADY / 812 wherein plants can grow. Non-limiting examples of a plant growth medium are soil, sand, gravel, a polysaccharide, mulch, compost, peat moss, straw, logs, clay, or a combination thereof. A plant growth medium can also include a hydroculture system or an in vitro culture system. Hydroculture is the growing of plants in a soilless medium or an aquatic based environment, while an in vitro culture system refers to the growing of plants or explants on or in a recipient with synthetic medium, in sterile conditions, in a controlled environment and in reduced space. Explants refer to parts of a plant, from all the aerial part to isolated cells, as parts of leaves, of roots, seeds, bulbs, tubers, buds. The inoculation of said plant growth medium with a microbial population can be done before, during and / or after sowing or before, during and / or after the start of the plant growth cycle in case of hydroculture or in vitro culture. The inoculation can be performed once or multiple times during the plant growth cycle. In one embodiment, the microbial population is applied to the plant growth medium as a powder, as a pellet, as a granule or as a liquid. The term “plant” as used herein encompasses whole plants and plant parts, including seeds, shoots, stems, leaves, roots (including tubers), bulbs, buds, flowers, and tissues and organs. The term “plant” also encompasses plant cells, suspension cultures, callus tissue, embryos, meristematic regions, gametophytes, sporophytes, pollen and microspores. Thus, in one embodiment, a method is provided for stimulating plant growth or yield comprising applying the microbial culture comprising the bacterial strain of current application to a plant, plant part, plant seed or to the plant growth medium. Unless otherwise specified, in the latter and further embodiments and aspects, “stimulating”, “enhancing”, “increasing” or “improving” refers to a statistically significant increase and / or an at least 5% increase or at least 6% increase or at least 7% increase or at least 8% increase or at least 9% increase or at least 10% increase or at least 12% increase or at least 15% increase or at least 20% increase or at least 25% increase or at least 30% increase or at least 50% increase or at least 75% increase or at least a 100% increase in the property being measured (e.g. plant growth, plant yield, nitrogen fixation) and compared to a mock or control situation. Plants that are particularly useful in the methods of current application include in particular nitrogen fixing plants or leguminous plants. Non-limiting examples of leguminous plants are acacia (genus Acacia), alfalfa (Medicago sativa), almendro (Dipteryx oleifera), bean (genus Phaseolus), common bean (P. vulgaris), green bean (P. vulgaris), lima bean (P. lunatus), scarlet runner bean (P. coccineus), bird’s-foot trefoil (Lotus corniculatus), bush clover (genus Lespedeza), broom (genus Cytisus), carob (Ceratonia siliqua), chickpea (Cicer arietinum), clover (genus Trifolium), cowpea (Vigna unguiculata), crown vetch (Securigera varia), fenugreek (Trigonella foenum-graecum), honey locust (Gleditsia species), hyacinth bean (Lablab purpureus), indigo (genus Indigofera), jícama (Pachyrhizus erosus), kakabeak (genus SoGo / BRADY / 812 Clianthus), Kentucky coffee tree (Gymnocladus dioica), kidney vetch (Anthyllis vulneraria), kudzu vine (Pueraria montana), laburnum (genus Laburnum), golden chain (L. anagyroides), genus Lathyrus, beach pea (L. japonicus), sweet pea (L. odoratus), lentil (Lens culinaris), licorice (Glycyrrhiza glabra), locoweed (Astragalus and Oxytropis species), locust (genus Robinia), logwood (Haematoxylum campechianum), lupine (genus Lupinus), Texas bluebonnet (L. texensis and L. subcarnosus), mesquite (genus Prosopis), mimosa (genus Mimosa), sensitive plant (M. pudica), narra (Pterocarpus species), pagoda tree (Styphnolobium japonicum), palo verde (genus Parkinsonia), pea (Pisum sativum), peanut (Arachis hypogaea), redbud (genus Cercis), rosary pea (Abrus precatorius), royal poinciana (Delonix regia), senna (genus Senna), silk tree (genus Albizia), smoke tree (Dalea spinosa), soybean (Glycine max), suicide tree (Tachigali versicolor), sunn hemp (Crotalaria juncea), tamarind (Tamarindus indica), vetch (genus Vicia), broad bean (V. faba), wisteria (genus Wisteria). In a particular embodiment, said leguminous plant is selected from the list consisting of alfalfa (Medicago sativa), bean (genus Phaseolus), common bean (P. vulgaris), green bean (P. vulgaris), lima bean (P. lunatus), scarlet runner bean (P. coccineus), chickpea (Cicer arietinum), clover (genus Trifolium), cowpea (Vigna unguiculata), fenugreek (Trigonella foenum- graecum), genus Lathyrus, beach pea (L. japonicus), sweet pea (L. odoratus), lentil (Lens culinaris), licorice (Glycyrrhiza glabra), pea (Pisum sativum), peanut (Arachis hypogaea), soybean (Glycine max), tamarind (Tamarindus indica), vetch (genus Vicia) and broad bean (V. faba). In a most particular embodiment, said leguminous plant is soybean (Glycine max), bean (Phaseolus sp.), lentils (Lens culinaris), chickpea (Cicer arietinum), clover (genus Trifolium), cowpea (Vigna unguiculata) or Lathyrus. In another aspect, a method for enhancing growth, yield and / or cold tolerance of a plant is provided, wherein said method comprises growing coated seeds of a plant, wherein said seeds are coated with a microbial population comprising an isolated bacterial strain of current application, to obtain enhanced growth, yield and / or cold tolerance of said plant. In one embodiment, said yield is seed yield or amount of seeds (e.g. expressed in tons) per acre or hectares. In another embodiment, said enhancing yield is enhancing the protein content of seeds, more particularly of seeds of a leguminous plant. Also provided is a method for enhancing nodulation or enhancing nitrogen fixation of a leguminous plant, wherein said method comprises growing coated seeds of said plant, wherein said seeds are coated with a microbial population comprising an isolated bacterial strain of current application. In some embodiments, after the coating procedure, the seeds should comprise at least 1x104, 1x105or 1x106living cells or spores of a bacterial strain of current application. An “effective amount” refers to an amount sufficient to effect beneficial or desired results. In a non- limiting example, an “effective amount” leads to a statistically significant increase of plant growth and / or SoGo / BRADY / 812 biomass and / or yield and / or cold tolerance and / or protein content of seed and / or nitrogen fixation as compared to the growth, biomass and / or yield and / or cold tolerance and / or protein content of seed and / or nitrogen fixation of the control plant. An effective amount can be administered in one or more administrations. A “control plant” as used in current application provides a reference point for measuring changes in phenotype of the subject plant and may be any suitable plant cell, seed, plant component, plant tissue, plant organ or whole plant. A control plant may comprise for example a plant or cell which is genetically identical to the subject plant or cell but which is not exposed to the same treatment (e.g. administration of the bacterial strain of current application) as the subject plant or cell. In another embodiment, a method is provided for enhancing nutrient uptake and / or nutrient use efficiency of a plant, said method comprising growing coated seeds of a plant, wherein said seeds are coated with a microbial population comprising the bacterial strain of current application, to obtain enhanced nutrient uptake and / or nutrient use efficiency of said plant. In another embodiment, a method is provided for enhancing nodulation or enhancing the nitrogen fixating capacity of a plant, said method comprising growing coated seeds of a plant, wherein said seeds are coated with a microbial population comprising a bacterial strain of current application, to obtain enhanced nodulation or enhanced a nitrogen fixating capacity of said plant. In yet another aspect, a method for enhancing growth, yield and / or cold tolerance of a plant is provided comprising: - growing a plant in an environment that supports plant growth; and - administering a sprayable formulation to said environment or to said plant, said formulation comprising a bacterial strain of current application; to obtain enhanced growth, yield and / or cold tolerance of said plant. In one embodiment, said yield is seed yield. In another embodiment, said enhancing yield is enhancing the protein content of seeds of said plant, more particularly a leguminous plant. Also a method for enhancing nodulation or enhancing nitrogen fixation of a leguminous plant is provided, comprising the steps of growing said plant in an environment that supports plant growth and administering a sprayable formulation to said environment or to said plant, said formulation comprising a bacterial strain of current application. A “sprayable formulation” as used herein is an agrochemical or a biological solution that can be sprinkled on a plant or soil. The formulation is composed in such a way that the active ingredients can be absorbed by the above-ground tissue of a plant or is available for the plant roots when administered to the soil. SoGo / BRADY / 812 The above disclosed methods thus also includes irrigation with a liquid comprising the bacterial strain of current application. “Irrigating” or “irrigation” as used herein refers to the method in which water or other liquids are supplied to plants at regular intervals. Irrigation includes but is not limited to “localized irrigation” (i.e. a system where water is distributed under pressure through a piped network, in a pre- determined pattern, and applied as a small discharge to each plant or adjacent to it. “Drip (or micro) irrigation”, also known as “trickle irrigation” (i.e. a system where water falls drop by drop just at the position of roots or near the root zone of plants) and “sprinkler irrigation” (i.e. a system where water is distributed by overhead sprinklers) belong to this category of irrigation methods. In “sprinkler irrigation”, sprinklers can also be mounted on moving platforms connected to the water source by a hose. Automatically moving wheeled systems known as traveling sprinklers may irrigate areas such as small farms, sports fields, parks and pastures unattended. Most of these utilize a length of polyethylene tubing wound on a steel drum. As the tubing is wound on the drum powered by the irrigation water or a small gas engine, the sprinkler is pulled across the field. When the sprinkler arrives back at the reel the system shuts off. This type of system is known to most people as a "waterreel" traveling irrigation sprinkler. Hence, in various embodiments, a method is provided for enhancing growth, yield and / or cold tolerance of a plant, said method comprising: - growing said plant in an environment that supports plant growth; - irrigating said environment using a liquid solution comprising a bacterial strain of current application; to obtain enhanced growth, yield and / or cold tolerance of said plant. In one embodiment, said yield is seed yield. In another embodiment, enhancing yield is enhancing the protein content of seeds of said plant, more particularly the seeds of a leguminous plant. Also provided is a method to increase nodulation or the nitrogen fixation of a leguminous plant comprising the steps of growing said plant in an environment that supports plant growth and irrigating said environment using a liquid solution comprising a bacterial strain of current application. In particular embodiments, when used as a soil treatment, a bacterial strain of current application can be applied as a soil surface drench, injected and / or applied in-furrow or by mixture with irrigation water. The rate of application for drench soil treatments, which may be applied at planting, during or after seeding, or after transplanting and at any stage of plant growth, is about 1x1011to about 8x1012cfu per acre. In some embodiments, the rate of application is about 1x1012to about 8x1012cfu per acre. The rate of application for in-furrow treatments, applied at planting, is about 2.5x1010to about 5x1011cfu per 1000 row feet. In some embodiments, the rate of application is about 6x1010to about 4x1011cfu per SoGo / BRADY / 812 1000 row feet. Those of skill in the art will understand how to adjust rates for broadcast treatments (where applications are at a lower rate but made more often) and other less common soil treatments. In some embodiments, when a bacterial strain of current application is applied as microbial population or bacterial population or solution or culture or agricultural composition or sprayable formulation, the number of colony forming units (cfu) per milliliter (ml) of said bacterial strain of current application in the microbial populations or bacterial populations or solutions or cultures or agricultural compositions or sprayable formulations will be at least 1x106cfu / ml or at least 1x107cfu / ml or at least 1x108cfu / ml or at least 1x109cfu / ml or at least 2x109cfu / ml or at least 3x109cfu / ml or at least 4x109cfu / ml or at least 5x109cfu / ml or at least 6x109cfu / ml or at least 7x109cfu / ml or at least 8x109cfu / ml or at least 9x109cfu / ml or at least 1x1010cfu / ml or at least 2x1010cfu / ml or at least 3x1010cfu / ml or at least 4x1010cfu / ml or at least 5x1010cfu / ml or at least 6x1010cfu / ml or at least 7x1010cfu / ml or at least 8x1010cfu / ml or at least 9x1010cfu / ml or at least 1x1011cfu / ml or at least 2x1011cfu / ml or at least 3x1011cfu / ml or at least 4x1011cfu / ml or at least 5x1011cfu / ml or at least 6x1011cfu / ml or at least 7x1011cfu / ml or at least 8x1011cfu / ml or at least 9x1011cfu / ml or at least 1x1012cfu / ml or at least 1x1013cfu / ml or at least 1x1014cfu / ml. Additional to the above detailed description of the invention, terminology as used in describing the aspects of the invention is described in the following sections. In all herein described aspects and embodiments – unless specified differently – “enhance” or “increase” or “improvement” refers to a statistically significant increase and / or an at least 1%, 2%, 3%, 4% or 5% increase or at least 6% increase or at least 7% increase or at least 8% increase or at least 9% increase or at least 10% increase or at least 15% increase or at least 20% increase or at least 25% increase or at least 30% increase or at least 50% increase or at least 75% increase or at least a 100% increase in the property being measured and compared to a control situation. Said control situation is a mock situation wherein the plant, plant seed or other plant part was not treated with the microbial population or bacterial strain herein disclosed. The skilled person is aware how a scientifically sound mock situation should be set up. “Treated” as used herein can be direct treatment (e.g. coating seeds or spraying plants) and / or indirect treatment (e.g. providing the substrate wherein the plant is growing with a bacterial population). The term “statistically significant” or “statistically significantly” different is well known by the person skilled in the art. Statistical significance plays a pivotal role in statistical hypothesis testing. It is used to determine whether the null hypothesis should be rejected or retained. It states that the results are obtained because of chance and are not supporting a real change or difference between two data sets. SoGo / BRADY / 812 The null hypothesis is the default assumption that what one is trying to prove did not happen. In contrast the alternative hypotheses states that the obtained results support the theory being investigated. For the null hypothesis to be rejected (and thus the alternative hypothesis to be accepted), an observed result has to be statistically significant, i.e. the observed p-value is less than the pre-specified significance level α. The p stands for probability and measures how likely it is that the null hypothesis is incorrectly rejected and thus that any observed difference between data sets is purely due to chance. In most cases the significance level α is set at 0.05. “Microbial” as used herein refers to microorganisms, wherein said microorganisms can include bacteria, archaebacteria, fungi, yeasts, mycorrhiza, microscopic eukaryotes (e.g. protozoa and algae), viruses, viroids or a combination thereof. A “microbial population” as used herein can thus refer to a synthetic or artificial collection of different microorganisms with distinct geographical origins. In various more particular embodiments of this application, “microbial” refers to “bacterial”. For the purpose of current application, the term “bacterium” or “bacteria” includes any prokaryotic organism that does not have a distinct nucleus. While being both part of the group of microorganisms, bacteria and fungi are clearly distinct. The term “fungi” or “fungus” includes a wide variety of nucleated spore-bearing organisms that are devoid of chlorophyll. In order to reconstruct the evolutionary relationships and sequence identity of one bacterial isolate to another, phylogenetic approaches are used standardly exploiting the 16S rRNA sequence or a portion of the 16S rRNA sequence of the bacteria, although any other sequence or the entire genome of the microorganisms to be analyzed can also be used. In microbiology, “16S rRNA sequence” refers to the sequence derived by characterizing the nucleotides that comprise the 16S ribosomal RNA gene(s). The bacterial 16S rRNA is approximately 1500 nucleotides in length. In this application “sequence similarity”, “sequence identity” and “sequence homology” are interchangeably used. The term “sequence identity” as used herein refers to the extent that sequences are identical on a nucleotide-by-nucleotide basis over a window of comparison. Thus, a “percentage of sequence identity” is calculated by comparing two optimally aligned sequences over the window of comparison, determining the number of positions at which the identical nucleic acid base (e.g., A, T, C, G, I) occurs in both sequences to yield the number of matched positions, dividing the number of matched positions by the total number of positions in the window of comparison (i.e., the window size), and multiplying the result by 100 to yield the percentage of sequence identity. A gap, i.e., a position in an alignment where a residue is present in one sequence but not in the other is regarded as a position with non-identical residues. Determining the percentage of sequence identity can be done manually, or by SoGo / BRADY / 812 making use of computer programs that are available in the art. Examples of useful algorithms are PILEUP (Higgins & Sharp, CABIOS 5:151 (1989), BLAST and BLAST 2.0 (Altschul et al. J. Mol. Biol.215: 403 (1990). Software for performing BLAST analyses is publicly available through the National Center for Biotechnology Information (http: / / www.ncbi.nlm.nih.gov / ). The term “plant growth promoting” as used herein, refers to a promoting effect on a wide range of growth and development properties of cultured plants or crops, including but not limited to increased root development, increased leaf area, increased plant yield, increased fresh or dry weight, increased seed yield, increased seed germination, increased photosynthesis, increase in accumulated biomass of the plant, increased nitrogen fixation or increased efficiency of nutrients such as nitrogen, phosphorus or potassium. “CFU” or “cfu” as used herein refers to colony-forming unit. This unit is well-known by the person skilled in the art of microbiology (as well as the methodology how to determine the number of colony-forming units) and is used to estimate the number of viable bacteria or fungal cells in a sample. “Viable” is defined as the ability to multiply via binary fission under controlled conditions. Counting with colony-forming units requires culturing the microbes and counts only viable cells, in contrast with microscopic examination which counts all cells, living or dead. The present invention is described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. Any reference signs in the claims shall not be construed as limiting the scope. The drawings described are only schematic and are non- limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn on scale for illustrative purposes. Where the term "comprising" is used in the present description and claims, it does not exclude other elements or steps. Where an indefinite or definite article is used when referring to a singular noun e.g. "a" or "an", "the", this includes a plural of that noun unless something else is specifically stated. Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein. The terms or definitions provided herein are solely to aid in the understanding of the invention. Unless specifically defined herein, all terms used herein have the same meaning as they would to one skilled in SoGo / BRADY / 812 the art of the present invention. Practitioners are particularly directed to Michael R. Green and Joseph Sambrook, Molecular Cloning: A Laboratory Manual, 4th ed., Cold Spring Harbor Laboratory Press, Plainsview, New York (2012); and Ausubel et al., Current Protocols in Molecular Biology (Supplement 47), John Wiley & Sons, New York (1999), for definitions and terms of the art. The definitions provided herein should not be construed to have a scope less than understood by a person of ordinary skill in the art. It is to be understood that although particular embodiments, specific configurations as well as materials and / or molecules, have been discussed herein for cells and methods according to the present invention, various changes or modifications in form and detail may be made without departing from the scope and spirit of this invention. The Examples described below are provided to better illustrate particular embodiments, and they should not be considered limiting the application. The application is limited only by the claims. EXAMPLES Example 1. Trapping native soybean nodulators To ensure protein rich beans, soy plants have to establish a symbiosis with nitrogen-fixing bacteria in their root nodules. Currently, the use of commercial inoculants in Belgian and North-West European soybean agriculture in general is insufficient for a reliable qualitative yield. To solve this problem, we initiated a nodulation trap experiment in gardens in Flanders. A total of 1200 candidates were selected out of 5335 applicants. All candidates received a unique ID number and were asked to create an account on the project website. In April 2021, each participant received a participation package containing soybeans (Glycine max cv. Acardia), a 10L plastic flower pot with participant ID sticker, ten plant labels, a flag to mark the north-western corner of the sowing grid and a standardized colour card with a ruler. In each garden one square meter was set up in a 6 x 10 grid to plant 60 soybeans. The project encompassed seven steps over the course of six months. Step 1 and 7 corresponded to extensive surveys. Steps 2 to 6 were dedicated to documenting the development of the plants in the participant gardens, each step corresponding to documenting specific parameters for a specific number of plants. To accommodate plant monitoring in the garden a platform was developed on the project website with each step changing into a clickable link once that specific step was enabled during the growing season. A digitally programmed 6 x 10 garden grid was available for each monitoring step, so participants could easily fill in parameters for each plant. Data could be entered or changed based on the step that was enabled and the data that the participant filled in in the previous step. SoGo / BRADY / 812 From mid-July to mid-August, participants were asked to bring back five of the ten plants they were closely monitoring. On collection day, participants removed the plants from their garden grid as instructed, marked them with a label corresponding with the grid coordinate, transferred them to an ID labelled pot and brought them to a drop-off spot. The next day, scientists picked up the plants for lab analysis, checked plant parameters such as shoot length and leaf chlorophyll content, made pictures of the whole plant and root system and further processed the roots. Nodules were photographed and stored at 4°C on silica until they were further processed for bacterial isolation and 16S rRNA amplicon sequencing. In total 4436 plants were returned to the lab of which 918 plants had root nodules or nodule like structures. We found 34 nodules with a red nodule interior (the colour of leghaemoglobin, demonstrating active nitrogen fixation in the nodules) originating from 27 gardens, 133 nodules with a white nodule interior coming from 80 gardens and 100 nodules with a brown (necrotic) nodule interior coming from 52 gardens. Two nodules of these 34 red nodules were the ones of which we could isolate R-85101 and R-85108 (Figure 1). Example 2. Identification and isolation of endogenous rhizobial bacteria In order to isolate and identify individual rhizobial bacterial strains residing in the soybean nodules, we rehydrated the stored nodules and sterilized these nodules using an in-house developed protocol. Nodules were cut into two equal halves and one halve of the nodule was squashed using a sterile plastic pestle, which was streaked on a R2A agar plate. Also 10 µL of the nodule juice was directly pipetted on an R2A plate, as well as an equal amount on a YMA plate. Nodule juices were spread out each time with a sterile Drigalski spatula. Subsequently, a 10x, 20x and 100 dilution was made of the nodule juice of which 30 µL was spread on R2A plates. Plates were incubated overnight at 28°C. The remaining nodule juice was mixed with 50% glycerol and stored at -20°C. For the streaked R2A and YMA plates, colony growth was checked after 24h, 48h, 5 days, 7 days and 14 days. After 14 days, single colonies were selected to re-plate by using the binocular (phenotype is checked). This re-plating was repeated and the colony phenotype was checked until colonies were pure. Once re-grown, a single colony from the pure isolate was taken and inoculated in a sterile 5 mL R2A broth. This broth was grown at 28°C under constant shaking and after 24h (i.e. at log phage, or until bacteria have grown) 0.9 mL of the culture was combined with 0.9 mL of sterile 50% glycerol and stored at -20°C. A pure colony was also streaked on a fresh R2A plate and incubated at 28°C and checked every day to check how fast the isolate grows. When it is at least in the third generation, it can be used for Matrix Assisted Laser Desorption / Ionization-Time-of-Flight Mass Spectrometry (MALDI-TOF MS). BioNumerics SoGo / BRADY / 812 was used to look at the obtained profiles and to cluster them next to partial 16S rRNA PCR sequencing to obtain their bacterial taxonomy. Currently, from the 1703 isolates we retrieved from the nodules collected, 630 unique strains have been identified, of which 21 are Bradyrhizobium spp. To confirm the nodulation potential of the isolated and selected strains, pot trials were set-up in a growth chamber under controlled environmental conditions. Five soybean varieties, Glycine max cv. Hermes (Protealis), Acardia (Saaten-Union), Lenka (Prograin), Aurelina (Saatbau Linz) and Gallec (Agroscope / DSP) were grown in an 8-week pot trail, using three repeats in a 16-h light / 8-h dark photoperiod at 20°C / 10°C. Pots were filled with 2L substrate, consisting of 50 v% fresh agricultural soil + 50 v% (0 / 2) sand (Leus N.V.) and soil samples were taken to check pH-KCl, %OC, NO3 / NH4, P, K, Ca, Mg, and Na in ammonium- lactate. In each pot trial, substrate from the same agricultural soil batch was used, but between pot experiments, different soil batches were collected. On the day of sowing, each pot received 200 mL water and 3 sowing holes of 1- 2 cm deep were prepared to sow 9 soybean seeds (3x3) of the same variety per pot. Per variety, 35 seeds were cultured in a 15mL exponentially growing bacterial solution OD 0.01. After sowing the seeds, water was given three times a week, with starting weight of 3750 g to avoid overwatering and adding 50 mL on the third and fifth day, which was increased upon plant growth. Two weeks after sowing, seedlings were reduced to 3 plants per pot. From week three onwards, plant height was measured each week and an overview picture was taken. At 8 weeks, plants were harvested. Fresh and dry weight of root and above ground biomass were measured, number of nodules was counted, nodule colour was checked, chlorophyll content was assessed and fresh and dry weight per nodule per plant was determined, next to storing some nodules at 4°C on silica for future reference. Detailed pictures are taken from the pot with the plants, the whole plants separately and the root system. Non-inoculated mock plants and plants inoculated with the commercial Bradyrhizobium inoculant G49, were used as negative and positive controls, respectively. The pot trials confirmed the nodulating ability of strains R-85101 and R-85108, and the laboratory grown control strain G49, in all five soybean varieties (Figure 2). No nodules were found on the mock plants, which were soaked in sterile demineralized water. Moreover, these nodules were either pink or red in all five soybean varieties tested. Example 3. R-85101 and R-85108 are novel strains BLAST analyses based on the 16S rRNA sequence of Bradyrhizobium sp. R85101 (SEQ ID NO: 1) revealed 100% similarity with Bradyrhizobium diazoefficiens USDA110. BLAST analyses based on the 16S rRNA SoGo / BRADY / 812 sequence of Bradyrhizobium sp. R85108 (SEQ ID NO: 2) revealed 100% similarity with Bradyrhizobium diazoefficiens USDA110. Next, the whole genome of the two isolated microbial Bradyrhizobium strains was sequenced, reads were assembled and contigs annotated. Different loci of the B. diazoefficiens R-85101 strain were BLASTed (i.e. atpD (ATP synthase subunit beta), recA (Protein recA), GyraseB, asd (aspartate-semialdehyde dehydrogenase), gnd (6-phosphogluconate dehydrogenase), sucA (2-oxoglutarate dehydrogenase E1) and zwf (glucose-6-phosphate 1- dehydrogenase) (Berkum et al 2006 J Bacteriol 188:5570-5577, doi:10.1128 / JB.00335). atpD shared 100% homology with Bradyrhizobium diazoefficiens strains 110spc4, USDA 110, XF19, XF16, XF14, XF10, XF6, XF5, XF4, XF1,HF08, F07S3 and 113-2. recA shared 100% homology with Bradyrhizobium diazoefficiens strains XF7, XF18, XF17, XF14, XF13, XF12, XF11, XF10, XF9, XF4, XF3, XF2, XF1, HH15, and H12S4, and with Bradyrhizobium sp. LCT2. GyraseB shared 100% homology with Bradyrhizobium diazoefficiens strains 110spc4, USDA 110, XF19, XF16, XF14, XF10, XF6, XF5, XF4, XF1, HF08, F07S3 and 113-2. asd shared 100% homology with Bradyrhizobium diazoefficiens strains XF7, strain 110spc4, USDA 110, XF19, XF18, XF17, XF16, XF15, XF13, XF12, XF11, XF9, XF8, XF6, XF5, XF3, XF2, HH15, HF08, H12S4, F07S3 and 113-2. gnd shared 100% homology with Bradyrhizobium diazoefficiens strains 110spc4, USDA 110, XF19, XF16, XF15, XF8 and 113-2. sucA shared 100% homology with Bradyrhizobium diazoefficiens strains XF7, 110spc4, USDA 110, XF18, XF17, XF16, XF15, XF14, XF13, XF12, XF11, XF10, XF9, XF8, XF6, XF5, XF4, XF3, XF2, XF1, HH15, HF08, H12S4, F07S3 and 113-2 zwf shared 100% homology with Bradyrhizobium diazoefficiens strains 172S4, 110spc4, USDA 122, CB1809, XF19, XF18, XF17, XF16, XF15, XF13, XF12, XF11, XF9, XF8, XF6, XF5, XF3, XF2, HH15, HF08, H12S4, F07S3, 113-2 and USDA 110 and with Bradyrhizobium sp. LCT2 Different loci of the B. diazoefficiens R-85101 strain were BLASTed (i.e. atpD (ATP synthase subunit beta), recA (Protein recA), GyraseB, asd (aspartate-semialdehyde dehydrogenase), gnd (6-phosphogluconate SoGo / BRADY / 812 dehydrogenase), sucA (2-oxoglutarate dehydrogenase E1) and zwf (glucose-6-phosphate 1- dehydrogenase) (Berkum et al 2006 J Bacteriol 188:5570-5577, doi:10.1128 / JB.00335). atpD shared 100% homology with Bradyrhizobium diazoefficiens strains 172S4, USDA 122 and CB1809, and with Bradyrhizobium sp. LCT2. recA shared 100% homology with Bradyrhizobium diazoefficiens strains 172S4, USDA 122 and CB1809. Gyrase B shared 100% homology with Bradyrhizobium diazoefficiens strains 172S4, USDA 122 and CB1809. asd shared 100% homology with Bradyrhizobium diazoefficiens strains 172S4,USDA 122, CB1809, XF14, XF10, XF4 and XF1. gnd shared 100% homology with Bradyrhizobium diazoefficiens strains 172S4, USDA 122, CB1809XF18 XF17, XF13, XF12, XF11,XF9, XF6, XF5, XF3, XF2, HH15, HF08, H12S4 and F07S3. sucA shared 100% homology with Bradyrhizobium diazoefficiens strains 172S4, 5463, USDA 122 and CB1809. zwf shared 100% homology with Bradyrhizobium diazoefficiens strains 172S4, 110spc4,USDA 122, CB1809, XF19, XF18, XF17, XF16, XF15, XF13, XF12, XF11, XF9, XF8, XF6, XF5, XF3, XF2, HH15, HF08, H12S4, F07S3, 113-2 and USDA 110, and with Bradyrhizobium sp. LCT2. Finally, the full genomes of Bradyrhizobium sp. R-85101 and Bradyrhizobium sp. R-85108 were compared with several publicly available Bradyrhizobium strains and the average nucleotide identity (ANI) values were determined (see Table 1). The ANI value is a measure of nucleotide-level genomic similarity between the coding regions of two genomes. It is clear from our analysis that the two isolated strains are novel strains. SEQ ID NO: 1 Bradyrhizobium sp. R-85101 (16S rRNA has 100% similarity with Bradyrhizobium diazoefficiens USDA 110) SEQ ID NO: 2 Bradyrhizobium sp. R-85108: 16S rRNA has 100% similarity with Bradyrhizobium diazoefficiens USDA 110) SoGo / BRADY / 812 Table 1. Whole Genome Sequence comparison with R-85101 and R-85108, ANI values are based on Illumina sequencing analysis R-85108 R-85101 Biodoz (G49) 99.9679 98.6884 Bradyrhizobium_algeriense_RST89.fna 79.4529 79.3136 Bradyrhizobium_amphicarpaeae_39S1MB.fna 88.0195 87.9298 Bradyrhizobium_arachidis_CCBAU_051107.fna 88.2008 88.1778 Bradyrhizobium_betae_PL7HG1.fna 88.5731 88.5203 Bradyrhizobium_cajani_1010.fna 88.4177 88.4805 Bradyrhizobium_cosmicum_58S1.fna 88.2257 88.1758 Bradyrhizobium_cytisi_CTAW11.fna 87.4188 87.4016 Bradyrhizobium_daqingense_CGMCC_1-10947.fna 88.7568 88.96 Bradyrhizobium_diazoefficiens_110spc4.fna 98.6988 99.6584 Bradyrhizobium_diazoefficiens_113-2.fna 98.6615 99.6807 Bradyrhizobium_diazoefficiens_172S4.fna 99.9807 98.6891 Bradyrhizobium_diazoefficiens_F07S3.fna 98.8056 99.675 Bradyrhizobium_diazoefficiens_H12S4.fna 98.7549 99.649 Bradyrhizobium_diazoefficiens_HF8.fna 98.8115 99.6962 Bradyrhizobium_diazoefficiens_HH15.fna 98.7504 99.6541 Bradyrhizobium_diazoefficiens_Is_1.fna 99.9826 98.7029 Bradyrhizobium_diazoefficiens_NK6.fna 98.6108 98.6371 Bradyrhizobium_diazoefficiens_SEMIA_5080.fna 99.9811 98.733 Bradyrhizobium_diazoefficiens_USDA_110.fna 98.7132 99.6766 Bradyrhizobium_diazoefficiens_USDA_122.fna 99.9839 98.7226 Bradyrhizobium_diazoefficiens_USDA_CCBAU_41267.fna 98.6852 99.6801 Bradyrhizobium_diazoefficiens_XF7.fna 98.7057 99.8022 Bradyrhizobium_diazoefficiens_Y21.fna 98.8016 99.6935 Bradyrhizobium_elkanii_BLY3-8.fna 80.7341 80.8953 Bradyrhizobium_elkanii_BLY6-1.fna 80.7552 80.9424 Bradyrhizobium_elkanii_BR29.fna 81.3754 81.6493 Bradyrhizobium_elkanii_CCBAU_05737.fna 81.5182 81.9902 Bradyrhizobium_elkanii_CCBAU_43297.fna 81.1378 81.101 Bradyrhizobium_elkanii_NBRC_14791.fna 81.1832 81.5598 SoGo / BRADY / 812 R-85108 R-85101 Bradyrhizobium_elkanii_SEMIA_5019.fna 81.5074 81.9164 Bradyrhizobium_elkanii_SEMIA_587.fna 81.5434 81.7772 Bradyrhizobium_elkanii_Semia_938.fna 80.8625 80.8519 Bradyrhizobium_elkanii_TnphoA_33.fna 81.4775 81.9835 Bradyrhizobium_elkanii_UASWS1015.fna 82.2808 82.3493 Bradyrhizobium_elkanii_USDA_61.fna 81.5832 81.735 Bradyrhizobium_elkanii_USDA_76.fna 81.2571 81.4792 Bradyrhizobium_elkanii_USDA_94.fna 81.0329 81.0858 Bradyrhizobium_elkanii_WSM1741.fna 79.5418 79.6805 Bradyrhizobium_elkanii_WSM2783.fna 80.0944 80.179 Bradyrhizobium_embrapense_SEMIA_6208.fna 80.6607 80.6939 Bradyrhizobium_guangdongense_CCBAU_51649.fna 86.5005 86.2748 Bradyrhizobium_guangdongense_CCBAU_51658.fna 86.2884 86.3487 Bradyrhizobium_guangdongense_CGMCC_1_15034.fna 86.3208 86.428 Bradyrhizobium_guangdongense_SM32.fna 84.3131 84.3991 Bradyrhizobium_guangdongense_XS1150.fna 88.0919 88.2385 Bradyrhizobium_guangxiense_CCBAU_53363.fna 87.6808 87.608 Bradyrhizobium_huanghuaihaiense_CGMCC_1.10948.fna 90.4706 90.373 Bradyrhizobium_icense_LMTR_13.fna 79.6118 79.4962 Bradyrhizobium_japonicum_22.fna 87.8157 87.7743 Bradyrhizobium_japonicum_5038.fna 89.9356 89.9197 Bradyrhizobium_japonicum_5873.fna 90.0195 89.9528 Bradyrhizobium_japonicum_CCBAU_15354.fna 89.4464 89.4101 Bradyrhizobium_japonicum_CCBAU_15517.fna 89.3972 89.4168 Bradyrhizobium_japonicum_CCBAU_15618.fna 90.1375 89.944 Bradyrhizobium_japonicum_CCBAU_25435.fna 89.6867 89.6515 Bradyrhizobium_japonicum_CCBAU_83623.fna 89.4248 89.3752 Bradyrhizobium_japonicum_E109.fna 89.9833 90.0149 Bradyrhizobium_japonicum_FN1.fna 89.939 90.0019 Bradyrhizobium_japonicum_in8p8.fna 87.0192 86.9502 Bradyrhizobium_japonicum_Is_34.fna 89.7106 89.6655 Bradyrhizobium_japonicum_is5.fna 86.9591 86.8416 SoGo / BRADY / 812 R-85108 R-85101 Bradyrhizobium_japonicum_J5.fna 90.0145 90.105 Bradyrhizobium_japonicum_NBRC_14783.fna 89.9475 89.9282 Bradyrhizobium_japonicum_SEMIA_5079.fna 90.0102 90.0655 Bradyrhizobium_japonicum_UBMA197.fna 88.8022 88.8227 Bradyrhizobium_japonicum_USDA_123.fna 89.3149 89.4266 Bradyrhizobium_japonicum_USDA_135.fna 88.5557 88.6104 Bradyrhizobium_japonicum_USDA_38.fna 89.8205 90.0438 Bradyrhizobium_japonicum_USDA_6.fna 89.9911 89.9751 Bradyrhizobium_jicamae_PAC68.fna 79.7928 79.706 Bradyrhizobium_lablabi_CCBAU_23086.fna 79.9485 79.8611 Bradyrhizobium_liaoningense_CCBAU_05525.fna 88.6109 88.7496 Bradyrhizobium_liaoningense_CCBAU_83689.fna 88.52 88.6759 Bradyrhizobium_liaoningense_CCNWSX0360.fna 87.8451 87.9504 Bradyrhizobium_lupini_DSM_30140.fna 89.931 89.9323 Bradyrhizobium_lupini_HPC(L).fna 69.3401 69.1462 Bradyrhizobium_manausense_BR_3351.fna 86.3395 86.3487 Bradyrhizobium_mercantei_SEMIA_6399.fna 80.8192 80.7995 Bradyrhizobium_nanningense_CCBAU_53390.fna 87.8172 87.8824 Bradyrhizobium_neotropicale_BR_10247.fna 86.5039 86.5979 Bradyrhizobium_nitroreducens_TSA1.fna 88.1993 88.1167 Bradyrhizobium_oligotrophicum_S58.fna 79.429 79.6572 Bradyrhizobium_ottawaense_OO99.fna 89.4506 89.5255 Bradyrhizobium_pachyrhizi_PAC_48.fna 80.8313 80.8913 Bradyrhizobium_paxllaeri_LMTR_21.fna 79.7816 79.7283 Bradyrhizobium_rifense_CTAW71.fna 87.2833 87.2209 Bradyrhizobium_shewense_ERR11.fna 88.0904 88.068 Bradyrhizobium_Soy223 90.0358 89.996 R-85101.fna 98.6945 100 R-85108.fna 100 98.6945 Bradyrhizobium_stylosanthis_BR_446.fna 88.5594 88.42 Bradyrhizobium_symbiodeficiens_85S1MB.fna 88.0994 88.0957 Bradyrhizobium_tropiciagri_SEMIA_6148.fna 80.7546 80.8517 SoGo / BRADY / 812 R-85108 R-85101 Bradyrhizobium_vignae_LMG_28791.fna 87.6245 87.7238 Bradyrhizobium_viridifuturi_SEMIA_690.fna 80.7522 80.8348 Bradyrhizobium_yuanmingense_3051.fna 87.4332 87.3381 Bradyrhizobium_yuanmingense_BR3267.fna 87.509 87.5546 Bradyrhizobium_yuanmingense_CCBAU_05623.fna 87.8192 87.9958 Bradyrhizobium_yuanmingense_CCBAU_10071.fna 87.585 87.6036 Bradyrhizobium_yuanmingense_CCBAU_25021.fna 87.5665 87.5855 Bradyrhizobium_yuanmingense_CCBAU_35157.fna 87.5026 87.4963 Bradyrhizobium_yuanmingense_CGMCC_1-3531.fna 87.5949 87.5343 Bradyrhizobium_yuanmingense_P10_130.fna 87.3797 87.4307 HiStick (532C) 90.0085 89.8825 Example 4. Comparison between R-85101, R-85108 and G49 The pot trials were set-up as discussed in example 2. Strain R-85108 resulted in a significantly higher nodule dry weight per plant compared to the positive control strain G49 for all five soybean varieties, an indicator for a potentially improved nitrogen fixating ability compared to G49. A similar trend of strain R-85108 can be seen in the chlorophyll content (Figure 4) and above ground dry biomass (Figure 4). Strain R-85101 performed similar to both strain R-85108 and the control G49 in all five soybean varieties, but generated a statistically higher chlorophyll content. Thus far, no significant soybean variety x rhizobial strain interactions have been observed in any of the assessed variables. Nonetheless, nodule number, chlorophyll content and above ground biomass show to be variety specific characteristics. Also a field trial was set-up in May 2022 in Merelbeke (Flanders, Belgium) on a sandy loam soil. Two soybean varieties were tested, Glycine max cv. Lenka (Prograin) and RGT Shouna (RAGT). A few weeks before sowing, a pre-emergence control was applied on the field with 1L Arundo, 1.5L Proman and 0.2 L Centium per hectare. Seeds were inoculated by coating them with an exponentially growing bacterial culture (OD 0.01) of interest and an adhesive (IMPF Signum Soy) with 0.001 mL bacterial culture per seed (estimated concentration of 10^6 CFU / mL or 1000 CFU / seed). Seeds were sown within 24h after inoculation (05 / 05 / 2022) (DD / MM / YYYY) with a sowing machine at a depth of + / - 3.5 cm with a row distance of 25.0 cm (5 rows per plot). The field trial was set up in a randomized complete block design (RCBD) with three replicates. Non-inoculated mock plants and plants inoculated with the commercial Bradyrhizobium inoculant G49, were used as negative and positive controls, respectively. At the R5 growing stage, chlorophyll content was followed up for four weeks and nodules were counted. Per plot, five random plants of the three inner rows were harvested in the front and the back of the plot (ten SoGo / BRADY / 812 plants per treatment). When nodules were present, they were counted, weighed and the colour was noted, next to storing some nodules at 4°C on silica for future reference. The remaining plants were harvested when the soybean plants reached physiological maturity –(R8 developing stage) on 5 / 10 / 2022 with a trial field thresher. After harvest, parameters such as thousand grain weight (4 x 100 grains), protein content, humidity content (approximately 1kg soybeans after harvest drying for 3 days at 70°C with humidity content (%) = 100% - dry weight / fresh weight x 100) and yield per hectare, after extrapolating yield / plot (kg), were measured. In general, RGT Shouna developed substantially more nodules on the roots than the variety Lenka, and issued a significantly higher nodule dry weight per plant. However, within the variety RGT Shouna strain R-85101 was more successful in forming red nodules compared to the control G49, and an initial variety x strain interaction can be observed (Figure 5).. For Glycine max cv. RGT Shouna, there was even a significantly higher number of nodules on the R-85101 treated plants as compared to G49 treated plants, i.e. the commercial control. Also the chlorophyll content of R-85101 and R-85108 treated plants was significantly higher for both soybean varieties tested and even significantly higher than the chlorophyll content of G49 treated plants (Figure 6). The yield at 15% moisture content (kg / ha) was significantly higher for both soybean varieties tested that were treated with R-85101 andR-85108 compared to the negative control (Figure 7). Moreover, for both soybean varieties tested, treatment with R-85108 caused a significantly higher yield as compared to the G49 treatment. Finally, also for both soybean varieties tested, an almost identical trend can be observed for the protein content (%), as R-85101 and R-85108 treated plants have a significantly higher protein content than the negative control (Figure 8), with R- 85108 treated plants even having a significantly higher protein content as compared to the commercial control G49. Experimental procedures Nodulation Soybean seeds were surface sterilized first with 70% ethanol and then with a bleach solution (29 ml sterile water, 15 ml NaClO, 12–13% (v / v) stock solution, and 1 ml Tween 20), where after they were washed five times for 15 min with sterile water and allowed to germinate for 4 days in the dark at room temperature. Seedlings of each cultivar were sown in sterilized vermiculite in 13-cm round pots and grown under a 16-h light / 8-h dark photoperiod at 22°C in the greenhouse. Plants were watered twice a week with nitrogen-poor SOLi solution. After one week, plants were inoculated with 1 ml of the respective bacteria at OD = 0.01. Four weeks after inoculation, the nodule presence was assessed and the nodules were photographed. These screening experiments were repeated independently seven times for each candidate isolate. The commercial Bradyrhizobium inoculant G49was used as positive control for nodule formation. Non-inoculated mock plants were used as negative controls.

Claims

SoGo / BRADY / 812 CLAIMS 1. An isolated Bradyrhizobium strain selected from the list: Bradyrhizobium sp. R-85101 having the deposit accession number LMG P-33069 and Bradyrhizobium sp. R-85108 having the deposit accession number LMG P-33070.

2. An enriched culture of the Bradyrhizobium strain according to claim 1.

3. A biologically pure culture of the Bradyrhizobium strain according to claim 1.

4. A composition comprising the Bradyrhizobium strain according to claim 1 or the culture according to claims 2-3.

5. The composition according to claim 4, wherein the Bradyrhizobium strain is lyophilized, freeze-dried to a powder or present as an aqueous slurry.

6. The composition according to claim 4 further comprising growth medium appropriate for Bradyrhizobium species and / or a cryoprotectant.

7. The composition according to any of claims 4-6 further comprising an agriculturally compatible carrier.

8. A plant seed coated with the Bradyrhizobium strain according to claim 1 or with the culture according to any of claims 2-3.

9. The plant seed according to claim 8, where the plant seed is a leguminous plant seed.

10. The plant seed according to claim 9, wherein the leguminous plant seed is a soybean seed.

11. Use of the Bradyrhizobium strain according to claim 1, the culture according to any of claims 2-3 or the composition according to any of claims 4-7 to enhance yield and / or nodulation of a leguminous plant.

12. Use of the Bradyrhizobium strain according to claim 1, the culture according to any of claims 2-3 or the composition according to any of claims 4-7 to enhance the protein content of seeds of a leguminous plant.

13. The use according to any of claims 11-12, wherein the leguminous plant is soybean.

14. A method for enhancing yield and / or nodulation of a leguminous plant or enhancing the protein content of the seeds of a leguminous plant, the method comprising the steps of: - inoculating a plant growth medium with a microbial population, said population comprises the Bradyrhizobium strain according to claim 1, the culture according to any of claims 2-3 or the composition according to any of claims 4-7; and - growing the leguminous plant in said plant growth medium.

15. The method of claim 14, wherein the microbial population is applied to the plant growth medium as a powder, as a pellet, as a granule or as a liquid.SoGo / BRADY / 812 16. A method for enhancing yield and / or nodulation of a leguminous plant or enhancing the protein content of the seeds of a leguminous plant, said method comprising growing the coated plant seed according to any of claims 8-10, to obtain enhanced yield and / or nodulation of said plant or an enhanced protein content of the seeds of said plant.

17. A method for enhancing yield and / or nodulation of a leguminous plant or enhancing the protein content of the seeds of a leguminous plant comprising: - growing said plant in an environment that supports plant growth; and - administering a sprayable formulation to said environment or to said plant, said formulation comprising the Bradyrhizobium strain according to claim 1, the culture according to any of claims 2-3 or the composition according to any of claims 4-7; to obtain enhanced yield and / or nodulation of said plant or enhanced protein content of the seeds of said plant.

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