Endophytic bacteria live within and colonize plant tissues, forming symbiotic interactions that often enhance host growth, health, and stress tolerance without causing harm. This study aimed to isolate endophytic bacterial strains from the medicinal plant ‘kratom’ (Mitragyna speciosa), characterize their biological functions by analyzing morphological, biochemical, and molecular properties, and evaluate their plant growth-promoting potential. The research followed standard procedures for isolating and analyzing the production of plant growth-promoting compounds, including indole-3-acetic acid, 1-aminocyclopropane-1-carboxylate deaminase, siderophores, cellulase, nitrogen fixation, and phosphate solubilization, and for assessing their effects on soybean in planta, including bacterial root colonization and plant growth. Of the isolates tested by 16S rDNA sequencing, five were successfu...