pH INFLUENCE ON SHELF LIFE OF LIQUID PGPR FORMULATIONS WITH Bacillus subtilis STRAINS

Yıl 2025, Cilt: 14 Sayı: 1, 14 - 24, 29.01.2025

Sevgi İşlek , Kemal Karaca , Rengin Eltem

https://doi.org/10.18036/estubtdc.1413386

Öz

Plant Growth Promoting Rhizobacteria (PGPRs) are bacteria that promote plant growth through both direct and indirect mechanisms. The formulation of PGPR inoculants is crucial for the efficacy and commercial success of microbial fertilizers. Formulation aims to optimize the survival of microbial strains under specific environmental conditions and enhance their capacity to promote plant growth. This process ensures protection of bacterial cells against harsh conditions such as high temperatures, desiccation, and storage, thereby extending product shelf life. Proper formulation of PGPR inoculants is a critical component for sustainable agricultural practices, playing a significant role in improving both plant health and productivity.

Among PGPR strains, Bacillus species are particularly produced and utilized as microbial fertilizers commercially due to their high efficacy potential and long shelf life. However, for large-scale production, strain-specific PGPR formulations need to be developed and optimized to produce PGPR inoculants with high efficacy potential and extended shelf life.

In this study, acidic liquid formulations were prepared using acetic acid for B. subtilis EGE-B-36.5 strain, and alkaline liquid formulations were prepared using calcium acetate-calcium hydroxide for B. subtilis EGE-B-1.19 strain. The viable cell count in the liquid formulations was statistically compared with the control. In the acidic liquid formulation, statistically significant changes in viable cell count were observed for B. subtilis EGE-B-36.5 strain at pH 4.0 after 12 months and for B. subtilis EGE-B-1.19 strain at pH 4.0 after 12 months (p<0.05). In the alkaline liquid formulation at pH 9.5 there had been a statistically significant (p<0.05) difference between control group of the B. subtilis EGE-B-1.19.

Anahtar Kelimeler

Bacillus subtilis, PGPRs, Microbial fertilizer, Liquid formulation, pH

Proje Numarası

FYL-2020-21642

Kaynakça

• [1] Singh M, Singh D, Gupta A, Pandey KD, Singh PK, Kumar A. Plant Growth Promoting Rhizobacteria. PGPR Amelioration in Sustainable Agriculture 2019; 41–66.
• [2] Chandini, Kumar R, Kumar R, Prakash O. The impact of chemical fertilizers on our environment and ecosystem. Research trends in environmental sciences 2019; 69-86.
• [3] Tabassum B, Khan A, Tariq M, Ramzan M, Iqbal Khan MS, Shahid N, Aaliya K. Bottlenecks in commercialisation and future prospects of PGPR. Applied Soil Ecology 2017; 121: 102–117.
• [4] Bhattacharyya PN, Jha DK. Plant growth-promoting rhizobacteria (PGPR): Emergence in agriculture. In World Journal of Microbiology and Biotechnology 2012; 28: 1327–1350.
• [5] Beneduzi A, Passaglia LM. Genetic and phenotypic diversity of plant growth promoting bacilli. In Bacteria in agrobiology: plant growth responses, Springer, Berlin, Heidelberg 2011; 1-20.
• [6] Akinrinlola RJ, Yuen GY, Drijber RA, Adesemoye AO. Evaluation of Bacillus Strains for Plant Growth Promotion and Predictability of Efficacy by In Vitro Physiological Traits. International Journal of Microbiology 2018; 1: 5686874.
• [7] Kumar A, Prakash A, Johri BN. Bacillus as PGPR in Crop Ecosystem, In Bacteria in Agrobiology: Crop Ecosystems, Springer, Berlin, Heidelberg 2011; 37–59.
• [8] Malusá E, Sas-Paszt L, Ciesielska J. Technologies for beneficial microorganisms inocula used as biofertilizers, In The Scientific World Journal 2012; 1: 491206
• [9] Lobo CB, Juárez Tomás MS, Viruel E, Ferrero MA, Lucca ME. Development of low-cost formulations of plant growth-promoting bacteria to be used as inoculants in beneficial agricultural Technologies. In Microbiological Research 2019: 219: 12–25.
• [10] Nakkeeran S, Fernando WD, Siddiqui ZA. Plant growth promoting rhizobacteria formulations and its scope in commercialization for the management of pests and diseases. PGPR: Biocontrol and biofertilization 2005; 257-296.
• [11] Bahadir PS, Liaqat F, Eltem R. Plant growth promoting properties of phosphate solubilizing Bacillus species isolated from the Aegean Region of Turkey. Turkish Journal of Botany 2018; 42(2): 183-196.
• [12] Oztopuz O, Sarigul N, Liaqat F, Park RD, Eltem R. Chitinolytic Bacillus subtilis Ege-B-1.19 as a biocontrol agent against mycotoxigenic and phytopathogenic fungi. Turkish Journal of Biochemistry 2019; 44(3): 323-331.
• [13] Liaqat F, Bahadır PS, Elibol M, Eltem R. Optimization of chitosanase production by Bacillus mojavensis EGE‐B‐5.2 i. Journal of basic microbiology 2018; 58(10): 836-847.
• [14] Kumar AP, Janardhan A, Radha S, Viswanath B, Narasimha G. Statistical Approach to Optimize Production of Biosurfactant by Pseudomonas aeruginosa 2297. 3 Biotech 2015; 5: 71-79.
• [15] Reuter CJ. Compositions for stabilizing Bacillus spores and methods of use thereof. 2011; U.S. Patent No. 20110200572
• [16] Daniels RS. Corn Steep Liquor as a biostimulant composition 2012; U.S. Patent No. 2012015454
• [17] Turan M. Mısır maserasyon sıvısı, çinko oksit, borik asit ile bakteri karışımından meydana gelen bir organik gübre. 2017; TR Patent No. 201613931
• [18] Wilks JC, Kitko RD, Cleeton SH, Lee GE, Ugwu CS, Jones BD, BonDurant SS, Slonczewski JL. Acid and base stress and transcriptomic responses in Bacillus subtilis. Applied and environmental microbiology 2009; 75(4): 981-99.
• [19] Bayram S, Aydogan MN. Searching for Versatile Polysaccharide-Degrading Alkali-tolerant or Alkaliphilic Bacillus Strains. Journal of the Institute of Science and Technology 2022; 12(1): 133-141.
• [20] Gauvry E, Mathot AG, Couvert O, Leguérinel I, Coroller L. Effects of temperature, pH and water activity on the growth and the sporulation abilities of Bacillus subtilis BSB1. International Journal of Food Microbiology 2021; 337:108915.
• [21] To HTA, Chhetri V, Settachaimongkon S, Prakitchaiwattana C. Stress tolerance-Bacillus with a wide spectrum bacteriocin as an alternative approach for food bio-protective culture production. Food Control 2022; 133: 108598.
• [22] Muis A. Biomass production and formulation of Bacillus subtilis for biological control. Indonesian journal of agricultural science 2006; 7(2): 51-56.
• [23] Issahary G, Evenchik Z, Keynan A. Low-p H Activation of Bacillus cereus Spores. Journal of Bacteriology 1970; 101(2): 418-422.
• [24] Vehapi M, Özçimen D. Investigation of B. subtilis viability at different pH ranges for use in microbial cleaner formulation. Bulletin of Biotechnology 2020; 1(1): 1-7.
• [25] Jha S, Singh R, Pandey A, Bhardwaj M, Tripathi SK, Mishra RK, Dikshit A. Bacterial toxicological assay of calcium oxide nanoparticles against some plant growth-promoting rhizobacteria. Int. J. Res. Appl. Sci. Eng. Technol 2018; 6(11): 460-466.
• [26] Chung S, Lim JH, Kim SD. Powder formulation using heat resistant endospores of two multi-functional plant growth promoting rhizobacteria Bacillus strains having phytophtora blight suppression and growth promoting functions. Journal of the Korean Society for Applied Biological Chemistry 2010; 53(4): 485-492.