Evaluation of plant probiotic performance of Pseudomonas sp. encapsulated in alginate supplemented with salicylic acid and zinc oxide nanoparticles.

Plant growth promoting rhizobacteria (PGPR) are efficient candidates for the application in agricultural field to enhance the crop yield and to suppress the plant diseases. As the changes in agro-climatic conditions negatively affect the soil fertility and functioning of soil microbial community, there are significant demand for the innovative delivery methods for the PGPR to ensure its optimal performance. In the present study, Pseudomonas sp. DN18 has been entrapped in the alginate beads along with the supplemented salicylic acid (SA) and zinc oxide nanoparticles (ZnONPs). This modified formulation was further demonstrated for the IAA production and also antifungal activity against the Sclerotium rolfsii. In addition, superior plant growth promoting and biocontrol properties of the encapsulated Pseudomonas sp. DN18 supplemented with SA and ZnONPs have also been demonstrated on Oryza sativa seedlings by comparing with the free living Pseudomonas sp. DN18. This revealed the agricultural promises of Pseudomonas sp. DN18 encapsulated in a modified delivery system due to its functional superiority and stability over the free living bacteria based formulation.