Investigating the formulation of alginate- gelatin encapsulated Pseudomonas fluorescens (VUPF5 and T17-4 strains) for controlling Fusarium solani on potato

Nanotechnology is one of the most fascinating sciences with a great potential to improve many agricultural products. Use of nanoparticles in plant disease management is a novel area which may prove very effective in future. Use of nanomaterials and biocompatible compounds in nano-encapsulation of antagonist bacteria is an important step in enhancing the efficiency of these agents in adverse environmental conditions. Two strains of Pseudomonas fluorescens (VUPF5 and T17-4) were used for alginate–gelatin nanocomposite beads with different concentrations of gelatin. The moisture content, swelling, and releasing of encapsulated viable bacteria was investigated in vitro and in vivo conditions. The results of FT-IR and X-ray diffraction analysis revealed that when gelatin was added into sodium alginate, electrostatic interaction occurred. The swelling and moisture content of nanocomposite beads grew with gelatin enhancement. The maximum encapsulation efficiency at the gelatin concentration of 1.5% in VUPF5 and T17-4 was 91.23% and 87.23%, respectively. Further, the greenhouse experiment showed that inoculation of potato with bacterial strains and nanocomposite beads of these strains reduced disease incidence. The encapsulation method described in this study can be effectively used to protect the plant probiotic bacteria inoculum from harmful conditions of the soil for its successful establishment in the rhizosphere.