KR20100053745A - Bacterial strains promoting plant growth by solubilizing rock phosphate and method for promoting plant growth using the same - Google Patents

Abstract

PURPOSE: A sulfur-oxidizing bacteria which promotes plant growth by solubilizing phosphate rock is provided to ensure plant growth promoting characteristic(PGP) and to improve yield and quality of crop. CONSTITUTION: A sulfur-oxidizing bacteria which promoting plant growth by solubilizing phosphate rock is Microbacterium phyllosphaerae ATSB31 (KACC 91417P) or Pandoraea sp. ATSB30 (KACC 91418P). A microorganism formulation or feed for promoting plant growth contains sulfur-oxidizing bacteria or culture medium thereof as an active ingredient. A biological feed is manufactured by culturing the sulfur oxidizing bacteria. A plant growth is promoted by solubilizing phosphate rock and additionally treating with 0.5-1.0% of glucose to a plant seed.

Description

Bacterial strains promoting plant growth by solubilizing rock phosphate and method for promoting plant growth using the same}

The present invention relates to a bacterial strain that solubilizes phosphate to promote plant growth, and more particularly, to a method for promoting plant growth using the same. More specifically, the present invention relates to a sulfated bacterium that solubilizes phosphate to promote plant growth. Or microbial agent and plant fertilizer for promoting plant growth comprising the culture solution thereof as an active ingredient, a method for producing the biofertilizer, soaking or irrigation of the strain in plants or seeds of plants to solubilize the phosphate to promote plant growth It is about how to.

Plant growth promoting rhizobacteria (PGPR) has long been studied. PGPR is a free-living soil bacterium that directly or indirectly promotes plant growth (Glick et al. 1995. Can. J. Microbiol., 41, 533-536). Direct promotion of plant growth includes providing enzymes ACC deaminase that can lower levels of iron, soluble phosphate, or plant ethylene sequestered by nitrogen, phytohormones, and bacterial siderophores immobilized on the plant. can do. The proposed function of ACC deaminase is that the concentration of ethylene cannot rise until a point where growth (especially root growth) is delayed. Indirect promotion of plant growth involves a variety of mechanisms by which bacteria prevent plant pathogens from inhibiting plant growth and development (Glick and Bashan 1997. Biotechnol. Adv., 15 , 353-378).

Sulfur (S) is one of the essential phytonutrients that accounts for about 10% of the total N content. In soil environments, most of the sulfur (over 95% of total sulfur) is bound to organic matter and is not directly available to plants. The use of sulfur oxidizing bacteria improves the natural oxidation rate of sulfur and accelerates the production of sulfates. This process makes sulfur more readily available to plants and consequently increases plant yield. Recently, the use of sulfur oxidizing bacteria as plant growth promoting bacteria is increasing trend. Few studies have reported on the availability of sulfur, the solubilization of phosphate or the improvement of plant growth promoting activity of sulfur oxidizing bacteria (Grayston and Germida 1991. Can. J. Microbiol., 37, 521-529). Most of the sulfur oxidizing bacteria used to promote plant growth are obligate chemolithoautotrophs. However, sulfur oxidizing bacteria are phylogenetically diverse and belong to several genera, including absolute and conditional chemically independent nutrients and heterotrophs. To date, there has been only one study on the sulfur oxidation and antagonistic activity of heterotrophic sulfur oxidizing bacteria (Grayston and Germida 1991. Can. J. Microbiol., 37, 521-529).

In recent years, the practical applicability of phosphate (RP) as a fertilizer has been important (Ghani et al. 1994. Soil Biol. Biochem., 26, 127-136). The RP was theoretically classified as the least expensive phosphorus fertilizer or most phosphorite deposits found in the world with low reactivity, and its direct practical use was not always found to be effective without pretreatment. Microbiological approaches have been proposed to enhance the agricultural value of RP. Anandham et al. (Anandham et al. 2007. World J. Microbiol. Biotechnol., 23, 1121-1129) report that RP-solubilized Burkholderia sp . And RP with glucose significantly improved phosphate solubilization. It was. When a mixture of RP and elemental sulfur is applied to the soil, the inoculated or indigenous population of thiobacilli oxidizes elemental sulfur to sulfuric acid. The acid produced reacts with the RP to form mono or dicalcium phosphate for absorption by plants.

Korean Patent No. 10-0460634 discloses a strain Enterobacter intermedius KSJ16 (KCTC 10387BP) that solubilizes insoluble phosphate, and Korean Patent No. 10-0460633 discloses a strain of solubilizing insoluble phosphate. Leclercia adecarboxylata KSJ8 (KCTC 10388BP) is disclosed, and Korean Patent Registration No. 10-0842450 discloses a novel strain of Cluivera sp. CL-2 and the solubilization of poorly soluble phosphate immobilized in soil using the same. A method is disclosed, and Korean Patent Registration No. 10-0842449 discloses a novel Pseudomonas sp. CL-1 strain and a method for solubilizing poorly soluble phosphate using the same, but the plant is prepared by solubilizing phosphate isolated from the root zone soil of the present invention. Different from bacterial strains that promote growth.

The present invention has been made in accordance with the above demand, and investigated the plant growth promoting properties in sulfated bacteria. The effect of sulfated bacteria containing 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase on root elongation of canola was evaluated under gnotobiotic conditions and sulfuric acid using thiosulfate as the sole sulfur source By measuring the bioacidualtion of RP by the bacterium, we attempted to develop bioinoculants containing sulfated bacteria by measuring the beneficial properties associated with plant growth promotion.

In order to solve the above problems, the present invention provides a sulfated bacterium which is separated from the rhizosphere soil and solubilizes the phosphate to promote plant growth.

The present invention also provides a microbial agent for promoting plant growth comprising the strain or its culture as an active ingredient.

The present invention also provides a bio-fertilizer for plant growth comprising the strain or its culture as an active ingredient.

In addition, the present invention provides a method for producing a biofertilizer by culturing the strain.

In addition, the present invention provides a method for promoting plant growth by solubilizing phosphate by dipping or irrigation of the strain in plants or seeds of plants.

According to the present invention, the sulfated bacterium of the present invention solubilizes phosphate ores and has a Plant Growth Promoting (PGP) property, and can positively affect plant growth, and thus, the sulfated bacteria as an effective plant growth promoting bacterium. Can broaden the range of bacteria beneficial for crop production. In addition, the novel strain of the present invention can be used to increase the yield and quality of crops by replacing the chemical fertilizer in eco-friendly organic farming where the use of fertilizer is limited.

In order to achieve the object of the present invention, the present invention provides a sulfated bacterium that solubilizes phosphate, separated from the rhizosphere soil, to promote plant growth.

The sulfated bacteria were selected based on thiosulfate consumption in mineral salts thiosulfate (MST) media through enrichment isolation from various root zone soils collected from crops grown in other regions of Korea. Among these isolates, strains that promote solubilization of phosphate to promote plant growth include Microbacterium phyllosphaerae ATSB31 (KACC 91417P), Pandoraea sp. ATSB30 (KACC 91418P), Halothiobacillus sp . ATSB2, Dyella ginsengisoli ATSB10, Pandoraea sputorum ATSB28, and the like.

These sulfated bacteria have been isolated from rhizosphere soils, oxidizing thiosulphate to sulfuric acid, causing a decrease in pH and promoting the solubilization of phosphate to promote plant growth. Preferably the strain is Microbacterium phyllosphaerae ATSB31 (KACC 91417P) or Pandoraea sp. ATSB30 (KACC 91418P).

Both strains markedly enhanced water extractable-P and bicarbonate extractable-P (see Table 3). Regardless of incubation time and glucose supplementation, Halothiobacillus sp . ATSB2 inoculation significantly increased water extractable-P and bicarbonate extractable-P (541 and 568 μg P / g RP) (Table 4).

The present invention also provides a microbial agent for promoting plant growth and a biofertilizer comprising a bacterial strain or a culture medium thereof, which solubilizes phosphate ore, isolated from the rhizosphere soil of the present invention to promote plant growth.

The microbial agent is a microbial bacteria strain Microbacterium phyllosphaerae ATSB31 (KACC 91417P), Pandoraea sp. ), Halothiobacillus sp.ATSB2, Dyella ginsengisoli ATSB10, Pandoraea sputorum ATSB28 as an active ingredient, preferably Microbacterium phyllospare ( Microbacterium phyllosphaerae ) ATSB31 (KACC 91417P) or Pandoraea sp. ATSB30 (KACC 91418P) may be included as an active ingredient. The microbial preparation according to the present invention may be prepared in the form of a liquid fertilizer and may be used in the form of powdered powder by adding an extender thereto or granulated by formulating it. However, the formulation is not particularly limited. In other words, it can be formulated as a biofertilizer to overcome this in eco-friendly organic farming where the chemical fertilizer supply is limited.

The present invention is isolated from the rhizosphere soil, solubilizing phosphate ore, bacteria bacterium microbacterium phyllosphaerae ATSB31 (KACC 91417P) or Pandoraea sp. ATSB30 (KACC 91418P) It provides the use as a bio fertilizer to promote the growth of crops. Using the culture medium cultured the strain it can be used as it is irrigation in a liquid state, immersed or sprayed on the seed of the crop or coated on the seed.

The present invention also provides methods for producing a micro tumefaciens Pillows paerae (Microbacterium phyllosphaerae) ATSB31 (KACC 91417P ) or a plate arrival O in (Pandoraea sp.) Biological fertilizer comprising the step of culturing the ATSB30 (KACC 91418P) according to the present invention To provide. The method for culturing the bacterial strain and the method for producing the biofertilizer may use any method known in the art, and is not particularly limited to a specific method.

The present invention also relates to immersing the microbacterium phyllosphaerae ATSB31 (KACC 91417P) or Pandoraea sp. ATSB30 (KACC 91418P) of the present invention, or a combination thereof, into a plant or plant seeds or It provides a method of solubilizing a phosphate ore comprising the irrigation treatment to promote plant growth. The method for promoting the growth of the plant may be carried out by immersing or irrigating a seed or plant in a culture medium in which two bacterial strains are cultured and a microbial preparation using the strain. In the case of the dipping method, the culture and the preparation may be poured into the soil around the plant or the seeds may be immersed in the culture and the preparation.

The method for promoting the growth of the plant of the present invention may comprise further treating 0.5-1.0% glucose. Glucose treatment increased phosphate solubilization compared to the non-glucose control (see Table 3).

Plants capable of promoting growth by the method of the present invention may include most of the plants, particularly effective in canola and the like.

Hereinafter, the present invention will be described in detail by way of examples. However, the following examples are illustrative of the present invention, and the present invention is not limited to the following examples.

1. Bacteria Strains and Culture Conditions

Sulfated bacteria are grown in mineral salts thiosulfate (MST) medium (Mukhopadhyaya et al. 2000. J. Bacteriol., 182, 4278-) by enrichment isolation from various root zone soils collected from crops grown in different regions of Korea. 4287). The isolates were selected based on thiosulfate consumption in MST medium. Isolated strains that consumed 10 mM thiosulfate (20 mM initial thiosulfate concentration in medium) at 4 days in MST medium were considered as efficient thiosulfate oxidation strains. The selected isolates were further characterized according to Deb et al. (Deb et al. 2004. Curr. Microbiol., 48, 452-458) and 16S rDNA technology. The bacterial strains were cultured in MST medium and DNA was extracted according to Sambrook et al. (1989) Molecular cloning: A laboratory Manual, Cold Spring Harbor Laboratory Press. New York. The gene encoding the bacterial 16S rRNA was amplified by PCR using forward primer 27f: 5'-AGAGTTTGATCCTGGCTCAG-3 '(SEQ ID NO: 1) and reverse primer 1492r: 5'-GGTTACCTTGTTACGACTT-3' (SEQ ID NO: 2). 16S rRNA nucleotide sequences were sequenced PCR directly using the fluorescent dye terminator method (ABI Prism ^™ Bigdye ^™ Terminator cycle sequencing ready reaction kit v.3.1) (Shima et al. 1994. FEMS Microbiol. Lett., 119, 119-122). The product was purified by Millipore-montage dye removal kit. Finally, the product was run with an ABI3730XL capillary DNA sequencer (50 cm capillary). Nearly complete 16S rRNA gene sequences were aligned from the automated sequencer, and bacterial entities were inferred by the BLAST program to determine the closest flexibility. The sequences obtained from the present invention were submitted to NCBI and detailed information and registration numbers of bacterial strains are shown in Table 1. Halothiobacillus strain ATSB2 was incubated for 4 days at 30 ° C. in mineral salt thiosulfate (MST) medium, while other bacterial strains were grown in Luria-Bertani (LB) medium (Difo Laboratories, Detroit, Michigan, USA). Incubated at 30 ° C. for 4 days.

2. Measurement of plant growth promoting properties

Nitrogen fixation ability was determined by (i) specific PCR methods of the nifH gene (Ueda et al. 1995. J. Bacteriol., 177, 1414-1417) and (ii) the presence of characteristic peel formation in the medium indicating nitrogen fixation. , Ability to grow in semi-solid nitrogen-free NFb medium. To test the mineral phosphate solubility, 5 μl of each bacterial strain was used as a source of inorganic phosphate (Pikovskaya 'agar medium) containing 0.5% tri-calcium phosphate (TCP) (Pikovskaya, RI, 1948). Mikrobiologiya, 17, 362-370). Plates were incubated at 30 ° C. for 4 days and TCP solubilization was confirmed by clear halo around bacterial colonies. Strains that showed positive results in plate analysis were selected for further quantitative analysis. Quantitative evaluation of solubilization was performed using Pykovskaya liquid medium. Erlenmeyer flasks (250 ml) containing 100 ml medium inoculated with 1 ml of bacteria (10 ⁷ cfu / ml) were prepared in each of three experiments. Sterile media without bacteria inoculation were used as controls. The flask was incubated in a shaker at 120 rpm for 4 days at 30 ° C., and the culture supernatant was obtained by centrifugation at 8000 g for 10 minutes. Soluble phosphate in the culture supernatant was determined by the molybdenum blue method (Murphy and Riley 1962. Anal. Chim. Acta., 273, 31-36). Production of indole in the culture supernatant was measured after incubating the bacteria for 4 days at 30 ° C. in DF minimal salt liquid medium (Dworkin and Foster 1958. J. Bacteriol., 75, 592-601) added 100 μg tryptophan / ml It was. 5 ml of culture was centrifuged at 8000 g for 15 minutes and 2 ml supernatant was transferred to a new tube and 100 μl of 10 mM orthophosphoric acid and 4 ml of Salkowasky reagent, 50 ml of 35 In% HClO ₄ 1 ml of 0.5 M FeCl ₃ is added). The mixture was allowed to react for 25 minutes at room temperature, and the absorbance of the pink color was measured at 530 nm (UV-spectrophotometer, UV-1601, Shimadzu, Japan). IAA concentrations in culture were determined by calibration curves generated using pure IAA as standard. Iron capture synthesis was measured according to the method by Schwyn and Neilands (Schwyn and Neilands 1987. Anal. Biochem., 160, 47-56). Culture supernatants were obtained by centrifugation at 8800 g for 10 minutes from bacteria grown for 4 days at 30 ° C. in standard succinate medium (Meyer and Abdallah 1978. J. Gen. Microbiol., 107, 319-328). Culture supernatants (60 μl) were spotted on CAS plates, with a dark yellow to orange coloration indicating a positive result of iron capture production. The determination of salicylic acid in the culture supernatant was performed according to Meyer et al. (Meyer et al. 1992. Biofactors, 4, 23-27). Enzyme β-1,3-glucanase activity was determined by Lim et al. 1991. Appl. Environ from a bacterium grown for 4 days at 30 ° C. in a peptone medium containing 0.2% laminarin digitata. Microbiol., 57, 510-516). For glucanase analysis, the reaction mixture (0.25 ml culture supernatant, 0.3 ml 0.1 M phosphate buffer (pH 5.5) and 0.5 ml 0.2% (v / v) laminarin) was reacted in a 40 ° C. water bath for 2 hours. . Enzyme glucanase activity was determined by μg glucose released per mg protein for 1 minute.

3. ACC  Deaminase activity and no infection status ( gnotobiotic Root height analysis

To measure the 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, bacterial isolates were incubated in 15 ml LB liquid medium until it reached a stop at 30 ° C., and the cells were centrifuged (8000 g). Obtained. To induce ACC deaminase activity, cells were resuspended in 7.5 ml DF minimal salt medium with 5 mM ACC added as the only nitrogen source, followed by shaking culture (120 rpm) at 30 ° C. for 40 hours. ACC deaminase activity was measured by production of α-ketobutyrate and expressed as α-ketobutyrate nM formed per 1 mg protein for 1 minute. An uninfected root elongation assay was used to assess the effect of ACC deaminase containing bacteria on the growth of canola hairs sensitive to ethylene levels in the early growth stages. Bacterial ACC deaminase activity was induced as described above. Cells were harvested and then sterile 0.03 M MgSO₄Washed with and resuspended. Seed treatment and gnotobiotic growth pouch analysis was performed using Penrose and Glick method (Penrose and Glick 2003. Physiol. Plant.,118, 10-15). Simply, canola (Brassica campestris, Hungnong seeds Seminis Korea Inc., Republic of Korea)₄ Or bacterial suspension (1x10)⁹cfu / ml) for 4 hours. The seeds were then transferred to a growth pouch (CYG seed germination pouch, Mega International Manufacturer, USA) uninfected, in a growth chamber with a temperature of 20 ± 1 ° C. and a relative humidity of 70% (DS 54 GLP, DASOL Scientific Co. , Ltd., Republic of Korea) 12h light conditions starting at 12h dark condition (18 μmol m^-2s^-OneCultured in cycles of). Six seeds were placed in one pouch; Ten pouches were used for each treatment and each treatment was tested with three replicates. Seeds that did not germinate 2 days after sowing were marked and roots developed from the seeds were not measured. The root length was measured on day 5 of growth and the data were analyzed statistically.

4. Acidification of phosphorite ( bioacidulation)

Factor experiments were performed by exposing RP with sodium thiosulfate to other strains of sulfated bacteria. These strains were selected based on differences in the form of nutrients, namely absolute chemolithoautotrophs and conditional chemo independent nutrients (Table 3). A sample (2 g) of RP (Morocco fluorapatite containing 12.8% of total P) was mixed with 1.5 g sodium thiosulfate (containing 0.39 g sulfur) and the mixture was placed in a 30 ml glass bottle. The proportions of RP and sulfur, ie thiosulfate, were similar to those needed to produce the sole super phosphate. RP was obtained from Office Che'rifien des Phosphates (Casablanca, Morocco). Bacterial cells were harvested by centrifugation, washed twice with brine (0.95% NaCl) and suspended. To RP was added bacteria suspended in saline containing 1 × ^{10 9} cells. Each bacterial strain was treated in three ways (unfilled or supplemented with 0.5 or 1% glucose). The moisture content of the mixture was adjusted to final 21% with distilled water. All glass bottles were kept at 30 ° C. under dark conditions for 45 days. Glass rods were placed in each glass bottle to mix RP and additives during the incubation. The vials were closed with plastic lids to maintain humidity during the incubation period. These lids were loosened for 30 minutes at intervals of 3-4 days to maintain an adequate supply of oxygen. The moisture content of the culture mixture was maintained on a weight basis. 36 vials were incubated for each treatment and sampled after 15, 30 and 45 days. When performing each sampling, 12 vials were removed from each treatment, and four vials samples were water extractable-P, bicarbonate extractable-P and pH analysis was performed.

5. Analysis method

At each sampling point, the culture mixture was transferred to a 200 ml volumetric extract bottle. A 50 ml extraction solution with distilled water or 0.5 M sodium bicarbonate (adjusted to pH 8.5 with NaOH) was added to the extraction bottle. This mixture was shaken at 40 rpm for 30 minutes at 20 ° C. After extraction, the suspension was washed with Whatman No. Filter with 42 filter paper. Water soluble and bicarbonate extractable-P was determined by the molybdenum blue method (Murphy and Riley 1962. Anal. Chim. Acta., 273, 31-36). The pH of the culture mixture was measured after mixing with distilled water (1: 2.5, solid: water), and left standing for 15 minutes with intermittent stirring, and then reading the value.

6. Statistical Analysis

The data includes general linear model version 9.1; The analysis of variance (ANOVA) was performed using SAS institute Inc, Cary, NC, USA. Means were compared with least significant difference (LSD). The significance level is the confidence limit below 0.05 (SAS, 2004).

Example  1: Potential plant growth promoting properties of sulfated bacteria

Sulfated bacteria isolated from the root zone of crops have other characteristics related to plant growth promotion (Table 1). All isolates tested except Dyella ginsengisoli can be grown in nitrogen-free medium. However, none of the strains produced positive products using nifH specific primers in PCR analysis. L. L. shinshuensis ATSB20 and ATSB24 produced IAA and soluble TCP from tryptophan. Of the 14 strains tested, five bacteria were found to solubilize TCP in qualitative (plate based) and quantitative (liquid medium based) assays. TCP solubilization activity was 181.2 ± 12 ( Microbacterium ) at 96.2 ± 6 ( Burkholderia kururiensis ) phyllosphaerae ) soluble P μg / ml range. Iron capture production was only pronounced in Pandoraea sputorum strains, and the accumulation of salicylic acid in the culture supernatant was observed in Alcaligenes genus. sp .), blood. P. pnomenusa ATSB25 and Pandoraea sp .) was observed in ATSB31. The activity of β-1,3 glucanase was non. It was observed in all strains except B. kururiensis . β-1,3 glucanase activity was 4.33 ± 0.8 ( Alcaligenes sp .) ranged from 413.2 ± 27 ( P. sputorum ATSB29) μg glucose / min.mg protein (Table 1).

Table 1.Promoting Plant Growth of Sulfated Bacteria

Example 2: Canola  For root elongation ACC -Effect of Sulfated Bacteria Containing Diaminase

The ACC- diaminase activity of the sulfated bacterial isolates ranged from 0.44 ± 0.1 ( P. sputorum ATSB28) to 53.6 ± 4 ( B. kururiensis ) nM α- ketobutyrate / min.mg protein. All isolates tested had a canola nacre root length of 56-166% greater than the control. The production of ACC-diaminase enzyme was not directly related to the increase in root length. P. sputorum ATSB28 had the lowest ACC-diaminase activity, but had the greatest effect on root elongation (Table 2).

Table 2. ACC-diaminase activity of sulfated bacteria and root elongation of canola

Example 3: acidification of phosphorite ( bioacidulation )

Bacterial inoculation caused a decrease in pH and markedly enhanced RP solubilization (Table 3).

Table 3. Changes in pH value, water extractability-P and bicarbonate extractability-P after 45 days of culture of RP inoculated with thiosulfate and inoculated with sulfated bacteria

The lowest pH (3.6) was di. D. ginsengisoli and Halothiobacillus sp .) was observed in the inoculated treatment. Day 45, Halothiobacillus genus without the highest water extractable-P (1219 μg P / g RP) supplemented with glucose blood supplemented with 0.5% glucose equivalent to RP inoculated with sp . Recorded at RP inoculated into P. sputorum . Similarly, Pandoraea supplemented with 1.0% glucose RP inoculated with sp .) recorded the highest bicarbonate extractability-P. Bicarbonate extractable-P was significantly higher than water extractable-P. Glucose supplementation markedly enhanced water extractable-P and bicarbonate extractable-P. Regardless of incubation time and glucose supplementation, Halothiobacillus sp . Inoculation significantly increased water extractable-P and bicarbonate extractable-P (541 and 568 μg P / g RP) (Table 4 ).

Table 4. Main Effects of Other Variables on pH Value, Water Extractability-P, and Bicarbonate Extractability-P

As the culture progressed, the addition of glucose and the inoculation of bacteria significantly reduced the pH of the RP mixture. However, no significant difference in pH reduction was found between the different bacterial strains.

Among them, two strains that significantly enhance phosphate solubilization, Microbacterium phyllosphaerae ATSB31 strain and Pandoraea sp. ATSB30 strain, were introduced to the Korea Agricultural Microbial Resources Center (KACC) in 2008. Deposited November 6 (Accession Numbers: KACC 91417P and KACC 91418P).

<110> Chungbuk National University Industry-Academic Cooperation Foundation <120> Bacterial strains promoting plant growth by solubilizing rock          phosphate and method for promoting plant growth using the same <130> PN08143 <160> 2 <170> KopatentIn 1.71 <210> 1 <211> 20 <212> DNA <213> Artificial Sequence <220> <223> Forward primer 27f <400> 1 agagtttgat cctggctcag 20 <210> 2 <211> 19 <212> DNA <213> Artificial Sequence <220> Reverse primer 1492r <400> 2 ggttaccttg ttacgactt 19  

Claims (7)

Microbacterium phyllosphaerae ATSB31 strain (KACC 91417P) that solubilizes phosphate to promote plant growth. Pandoraea sp. ATSB30 strain (KACC 91418P) that solubilizes phosphate to promote plant growth. A microbial preparation for promoting plant growth, comprising the strain of claim 1 or 2 or a culture thereof as an active ingredient. Bio-fertilizer for plant growth comprising the strain of claim 1 or 2 or a culture thereof as an active ingredient. A method for preparing a biofertilizer comprising culturing the strain of claim 1 or claim 2. A method of promoting plant growth by solubilizing phosphate ore, the method comprising immersing or irrigating the strain of claim 1 or 2 into a plant or seed of a plant. 7. The method of claim 6, further comprising 0.5-1.0% glucose.