Abstract Drought is responsible for almost 70% of total crop damage in tropical and subtropical countries. In the Colombian Caribbean, drought has caused low availability of Guinea grass ( Megathyrsus maximus ) in forage amount and quality, generating increase in production costs in livestock systems. In this study, we aimed at designing and evaluating dry macro-polymeric inoculants of Bacillus strains and used them successfully to mitigate drought effect on Guinea grass ( M. maximus ). We chose Bacillus sp XT13 and Bacillus megaterium XT14 strains, previously selected for their capacity to mitigate drought stress on Guinea grass. For the inoculant formulation process, a concentration of 3.2% alginate was used for both microorganisms, selecting the polymer-bacterium ratio of 70:30 for XT13 and 80:20 for XT14. The results of the experiments in greenhouse showed that drought had a negative effect on Guinea grass growth, but the PGPB application with or without macro-polymeric dry matrix improved plant growth significantly. We also observed that co-inoculation of the strains generated a greater beneficial effect than individual inoculation. Interestingly, co-inoculation of XT13 and XT14 under the dry macro-polymeric formulation increased biomass production of the aerial part (7.32%), root biomass, (25.3%), nutritional quality parameters, such as digestibility (3.32%), protein (20.3%); proline accumulation increased (21.06%) and both neutral digestible fiber (2.43%) and APX antioxidant activity (24.2%) decreased with respect to co-inoculation of both bacteria without formulation. These findings have shown that dry macrobeads immobilization has a significantly positive influence on the capacity of XT13 and XT14 bacterial strains to induce drought stress tolerance in Guinea grass.