The use of plant-growth-promoting rhizobacteria can lead to significant increases in crop productivity and reduce the use of synthetic inputs and production costs and is considered a sustainable practice. This study aimed to biochemically characterize bacteria with the potential to promote plant growth. For each biochemical characteristic (nitrogen assimilation; the solubilization of phosphate, zinc oxide, and potassium; and the production of hydrogen cyanide, indole acetic acid, and biofilms), an experiment was conducted using twenty-nine treatments, namely M01 (Bacillus sp.), M02 (Priestia megaterium), M03 (Pseudomonas sp1.), M04 (Pseudomonas sp2.), M05 (Enterobacter hormaechei), M06 (Bacillus toyonensis), M07 (Serratia nematodiphila), M08 to M28 (a combination of microorganisms), and M29 (the control, without microorganisms). All of the microorganisms, except for M01, assimilated nitrogen. Phosphorus was solubilized by all of the microorganisms, both when isolated and in mixtures. The microorganisms in treatments M01, M06, M08, M11, M12, M17, and M26 solubilized zinc. Potassium was solubilized by the microorganisms in treatments M02, M03, M04, M06, M08, M09, M10, M12, M14, M15, M17, M19, M21, and M24. Microorganisms M01, M05, and M07, both when isolated and combined, produced biofilms. Except for the microorganisms in treatments M01, M06, M12, and M13, all of the others produced HCN. All of the microorganisms produced indole acetic acid. Overall, the data suggest that combining certain bacterial strains can enhance their biochemical functions. The selection of specific bacterial combinations can be strategically tailored to improve plant-growth-promoting activities.