Characterization of culture condition dependent, growth responses of phosphate solubilizing bacteria (Bacillus subtilis DR2) on plant growth promotion of Hordeum vulgare

, , , ,

Research Articles | Published:

Print ISSN : 0970-4078.
Online ISSN : 2229-4473.
Pub Email:
Doi: 10.1007/s42535-023-00589-2
First Page: 266
Last Page: 276
Views: 1144

Keywords: Rhizosphere, Phosphate solubilization, 16S rRNA gene sequence, n Bacillus subtilisn , Barley seedlings


Phosphorus (P) is one of the essential macro nutrients required for the growth and development of plant. Phosphate solubilising bacteria (PSB) are very effective in improving soil fertility by solubilising insoluble soil P, making them readily available to the plants. In the present work, PSB were isolated from the rhizosphere of Eragrostis cynosuroides on Pikovskaya’s agar media at 30 °C and pH 7. Among positive isolates, the isolate DR2 was selected, based on highest zone of solubilization (15 mm), phosphate solubilization efficiency (150%) and solubilization index (4.5) on 4th day of incubation period. The isolated DR2 was identified as Bacillus subtilis on the basis 16 S rRNA gene sequence (Gene bank Accession Number KP455653). Optimized cultural conditions resulted in maximum P-solubilization after 96 h of incubation at 35 °C in Pikovsakaya’s broth (having 1% TCP) of pH 7.0 with glucose and ammonium sulphate, used as carbon and nitrogen sources, respectively. B. subtilis DR2 significantly enhanced the growth of barley seedlings in terms of seed germination (60%) with percent enhancements in root length (93.71%), shoot length (41.30%) and biomass (22.44%), over control. The strain B. subtilis DR2 can be used as a biofertilizer for a sustainable integrated plant nutrient supply (IPNS) system.

Rhizosphere, Phosphate solubilization, 16S rRNA gene sequence, n              Bacillus subtilisn            , Barley seedlings

*Get Access

(*Only SPR Members can get full access. Click Here to Apply and get access)



Balamurgan A, Princy T, Vidhyapallavi R, Nepolean P, Jayanthi R, Premkumar R (2010) Isolation and characterization of phosphate solubilizing bacteria in Tea. J Biosci 1:285–293

Baliah NT, Begum PJ (2015) Isolation, identification and characterization of phosphate solubilizing bacteria (PSB) isolated from economically important crop plants. Inter J Curr Micro Appl Sci 4(3):915–924

Banerjee S, Palit R, Sengupta C, Standing D (2010) Stress induced phosphate solubilization by Arthrobacter sp. and Bacillus sp. isolated from tomato rhizosphere. Aus J Crop Sci 4:378–383

Bhadaniya N, Patel A, Divya MD, Rathod Z, Saraf M (2021) Strategy of salt tolerance and productive effects of Bacillus tequilensis Under Specific Conditions. Inter J Scientific Enginee Appl Sci (IJSEAS) 7(4): 181–192

Cardinale M, Ratering S, Suarez C, Montoya AMZ, Geissler-Plaum R, Schnell S (2015) Paradox of plant growth promotion potential of rhizobacteria and their actual promotion effect on growth of barley (Hordeum vulgare L.) under salt stress. Micro res 181:22–32.

Dey R, Pal KK, Bhatt DM, Chauhan SM (2004) Growth promotion and yield enhancement of peanut (Arachis hypogaea L.) by application of plant growth promoting rhizobacteria. Microbiol Res 159:371–394.

Eramma, Mahadevaswamy, Rao S, Ramesh YM, Naik NM (2020) Isolation and Screening of Phosphate Solubilizing Bacteria from Paddy Rhizosphere Soil. Inter J Curr Microbiol App Sci 9(02):477–485.

Gupta R, Kumari A, Sharma S, Alzahrani OM, Noureldeen A, Darwish H (2022) Identification, characterization and optimization of phosphate solubilizing rhizobacteria (PSRB) from rice rhizosphere. Saudi J Biol Sci 29(1):35–42.

Harwood WA (2019) An Introduction to Barley: The Crop and the Model. In: Harwood, W. (eds) Barley. Methods in Molecular Biology, vol 1900. Humana Press, New York, NY.

Holt JG, Kreig NR, Sneath PHA, Staley JT, Williams ST (1994) Berge’s Manual of Determinative Biology, 9th ed., Williams and Wilkins, Baltimore, Maryland, USA

Jackson ML (1967) Soil Chemical Analysis. 1st Edn, Prentice Hall of India Pvt Ltd, New Delhi, India

Jena SK, Rath CC (2013) Optimization of culture conditions of phosphate solubilizing activity of bacterial sp. isolated from Similipal biosphere reserve in solid-state cultivation by response surface methodology. Int J Curr Microbiol Appl Sci 2(5):47–59

Kannapiran E, Ramkumar VS (2011) Isolation of phosphate solubilizing bacteria from the sediments of Thondi coast, Palk Strait, Southeast coast of India. Ann Biol Res 2(5):157–63

Kongbrailatpam B, Putatunda C (2018) In vitro Phosphate Solubilization by Bacillus subtilis PSBN B4 obtained from Pineapple (Ananas comosus) rhizosphere. Inter J Appl Environ Sci 13(9): 833–842

Kumar P, Aeron A, Shaw N, Singh A, Bajpai VK, Pant S, Dubey RC (2020) Seed bio-priming with tri-species consortia of phosphate solubilizing rhizobacteria (PSR) and its effect on plant growth promotion. Heliyon 6(12):e05701

Kumar P, Dubey RC, Maheshwari DK (2012) Bacillus strains isolated from rhizosphere showed plant growth promoting and antagonistic activity against phytopathogens. Micro Res 167(8):493–499.

Kumar P, Pahal V, Gupta A, Vadhan R, Chandra H, Dubey RC (2020) Effect of silver nanoparticles and Bacillus cereus LPR2 on the growth of Zea mays. Sci Rep 10(1):1–10.

Kumar P, Rai AK, Gupta A, Phukon H, Singh A, Kalita D, Sharma S, Harshvardhan K, Dubey RC (2021) Pesticide-degrading and phosphate solubilizing bacilli isolated from agricultural soil of Punjab (India) enhance plant growth. Microbiology 90:848–856.

Kumari PP, Gupta PC (2013) Effect of different carbon and nitrogen sources on solubilization of insoluble inorganic phosphate by psychrotolerant bacterial strains. Bioscan 8:1299

Maheswar NU, Sathiyavani G (2012) Solubilization of phosphate by Bacillus sps, from groundnut rhizosphere (Arachis hypogaea L.). J Chem Pharma Res 4(8):4007–4011

Malleswari D, Bhagyanarayana G(2013) Pantoeaeucrina (Cf7) a novel plant growth promoting rhizobacterium from India. Ann Biol Res 4:139–144

Mazylyte R, Kaziuniene J, Orola L, Valkovska V, Lastauskiene E, Gegeckas A (2022) Phosphate solubilizing microorganism Bacillus sp. MVY-004 and its significance for biomineral fertilizers’ Development in Agrobiotechnology. Biology 11(2):254.

Meena MK, Gupta S, Datta S (2016) Antifungal potential of PGPR, their growth promoting activity on seed germination and seedling growth of winter wheat and genetic variabilities among bacterial isolates. Inter J Curr Microbiol App Sci 5(1):235–243.

Minakshi SS, Sood G, Chauhan A (2020) Optimization of IAA production and P-solubilization potential in Bacillus subtilis KA(1)5r isolated from the medicinal herb Aconitum heterophyllum-growing in western Himalaya, India. J Pharmacogn Phytochem 9(1):2008–2015

Mohamed EA, Farag AG, Youssef SA (2018) Phosphate solubilization by Bacillus subtilis and Serratia marcescens isolated from tomato plant rhizosphere. J Environ Protec 9(03):266–277.

Naik SK, Maurya S, Kumar R, Choudhary JS, Das B, Kumar S (2013) Evaluation of rhizospheric fungi from acid soils of Jharkhand on phosphate solubilization. Bioscan 8(3):875–880

Narveer, Vyas A, Kumar H, Putatunda C (2014) In vitro Phosphate Solubilization by Bacillus sp. NPSBS 3.2.2 obtained from the Cotton Plant Rhizosphere. Bios Biotec Res Asia 11(2):401–406.

Panda P, Chakraborty S, Ray DP, Mahato B, Pramanik B, Choudhury A (2015) Solubilization of tricalcium phosphate and production of IAA by phosphate solubilizing bacteria isolated from tea rhizosphere soil. Eco Affairs 60(4):805–809.

Pande A, Pandey P, Mehra S, Singh M, Kaushik S (2017) Phenotypic and genotypic characterization of phosphate solubilizing bacteria and their efficiency on the growth of maize. J Genetic Enginee Biotech 15(2):379–391.

Reetha S, Bhuvaneswari G, Thamizhiniyan P, Ravi Mycin T (2014) Isolation of indole acetic acid (IAA) producing rhizobacteria of Pseudomonas fluorescens and Bacillus subtilis and enhances growth of onion (Allium cepa L.). Int. J Curr Micro Appl Sci 3:568–574

Richardson AE, Lynch JP, Ryan PR, Delhaize E, Smith FA, Smith SE, Harvey PR, Ryan MH, Veneklaas EJ, Lambers H, Oberson A, Culvenor RA, Simpson RJ (2011) Plant and microbial strategies to improve the phosphorus efficiency of agriculture. Plant Soil 349:121–156.

Rosas SB, Avanzini G, Carlier E, Pasluosta C, Pastor N, Rovera M (2009) Root colonization and growth promotion of wheat and maize by Pseudomonas aurantiaca SR1. Soil Biol Biochem 41:1802–1806.

Sagervanshi A, Kumari P, Nagee A, Kumar A (2012) Media optimization for inorganic phosphate solubilising bacteria isolated from an agriculture soil. Inter J Life Sci Pharma Res 2(3):245–255

Sahin F, Cakmakci R, Kantar F (2004) Sugar beet and barley yields in relation to inoculation with N2- fixing and phosphate solubilizing bacteria. Plant Soil 265:123–129

Sahu MK, Sivakumar K, Kannan L (2007) Phosphate Solubilizing Actinomycetes in the Estuarine Environment: An inventory. J Environ Biol 28:795–798

Sanjotha G, Manawadi S (2016) Isolation, Screening and Characterization of Phosphate Solubilizing Bacteria from Karwar Costal Region. Inter J Res Studies Micro Biotech (IJRSMB) 2(2):1–6.

Selvi KB, Ravindran AD (2012) Influence of different carbon and nitrogen sources on insoluble inorganic phosphate solubilization by Bacillus subtilis. Inter J Adva Biol Biom Res 2:441–445

Shahab S, Ahmed N (2008) Effect of Various Parameters on the Efficiency of Zinc Phosphate Solubilization by Indigenous Bacterial Isolates. Afr J Biotechnol 7(10):1543–1549.

Shaikh SS, Saraf MS (2017) Optimization of growth conditions for zinc solubilizing plant growth associated bacteria and fungi. J Adv Res Biotech 2(1):1–9.

Sharma SB, Sayyed RZ, Trivedi MH, Gobi TA (2013) Phosphate solubilizing microbes: sustainable approach for managing phosphorus deficiency in agricultural soils. SpringerPlus 2(1): 1–14

Sridevi M, Mallaiah KV (2009) Phosphate Solubilization by Rhizobium strains. Indian J Microbiol 49(1):98–102.

Tamura K, Dudley J, Nei M, Perin L (2007) Molecular Evolutionary Genetics Analysis (MEGA) Software Version 4.0, Molec Bio Evol 24:1596–1599.

Wang YY, Li PS, Zhang BX, Wang YP, Meng J, Gao YF, He XM, Hu XM (2020) Identification of phosphate solubilizing microorganisms and determination of their phosphate solubilizing activity and growth promoting capability. Bio Resource 15(2):2560–2578.



The authors acknowledge the support of the Head, Department of Botany, Patna University, Patna, for providing the necessary facilities for completion of this work. The authors are also thankful to Xcelris, India for the molecular confirmation of our isolates by 16 S rRNA gene sequencing.

Author Information

Kumari Sonali
Microbial Bioaffiliationersity Lab, Department of Botany, Patna University, Patna, India
Kumar Pankaj
Department of Microbiology, Dolphin (PG) Institute of Biomedical and Natural Sciences, Dehradun, India

Kiran Shilpi
Department of Botany, Patna Women’s College, Patna University, Patna, India

Kumari Sushma
Microbial Bioaffiliationersity Lab, Department of Botany, Patna University, Patna, India

Singh Abha
Microbial Bioaffiliationersity Lab, Department of Botany, Patna University, Patna, India