Bio-inspired core-shell microcapsules enhance storage stability and soil survival of non-spore bacteria for improving plant salinity tolerance

Non-spore-forming bacteria exhibit remarkable species diversity and sophisticated salt-resistance mechanisms, making them predominant candidates for commercial microbial inoculants worldwide. However, their low viability during storage and field application has severely constrained utilization. Inspired by the robust structure of spore dormancy, we propose a novel core-shell microcapsule (APC). Using Pantoea alhagi NX-11 as a model, APC encapsulation improved viability from 2.95 to 8.43 log CFU/g after 12-week storage at room temperature. The survival mechanism is attributed to APC-induced metabolic dormancy via suppression of the TCA cycle and oxidative phosphorylation pathways. Notably, compared to non-encapsulated NX-11, inoculation of APC-encapsulated NX-11 increased rice root dry weight by 24.61% under salt stress in greenhouse experiments and altered rhizosphere bacterial community structure. NX-11 showed higher relative abundance in rhizospheres treated with APC-encapsulated NX-11. Universality was validated in two additional non-spore bacterial strains. These results demonstrate APC’s efficacy in preserving non-spore microbial inoculants and enhancing plant salt stress tolerance, highlighting a novel approach for microbial formulation development.