Formulating rhizosphere consortia: Harnessing plant growth-promoting rhizobacteria for enhanced agricultural sustainability

Abstract

The development of efficient rhizosphere consortia using Plant Growth Promoting Rhizobacteria (PGPR) plays a significant role in enhancing plant growth and agricultural sustainability. This study focuses on formulating a rhizosphere consortium by utilizing eight different PGPR strains, including Bradyrhizobium japonicum (SB-120), Pseudomonas striata (PSB), Bacillus sp. (KSB), Zinc solubilizing bacterium (ZnSB), Silica solubilizing bacterium (SiSB), Actinobacterium (JK-16), Pink pigmented facultative methylotroph (PPFM-33) and Lactic acid bacterium (LAB-75). These strains were characterized based on their plant growth-promoting traits such as nitrogen fixation, indole acetic acid production, and solubilization of essential nutrients like phosphorus and potassium. Various combinations were formulated using a common growth medium, Luria Bertani, amended with additives like polyethylene glycol and glycerol. The formulation demonstrated that six PGPR strains, when combined, maintained high efficacy and offered a viable alternative to single-strain inoculants.