Summary: | Beneficial soil microorganisms influence nutrient recycling, soil fertility, plant growth, and productivity and reduce chemical fertilizer application. This study aimed to isolate bacteria from non-agricultural soils in the Al-Ahsa region and characterize the bacteria with the best biostimulating characteristics at the physiological, biochemical, and molecular level. DPM17, a bacterial isolate, promotes plant growth through phosphate solubilization, nitrogen fixation, and ammonia production. DPM17 also produces the phytohormones, indole acetic acid (IAA; 4.516 μg mL<sup>−1</sup>) and gibberellin (1.33 µg mL<sup>−1</sup>), and ammonia (0.06 µg mL<sup>−1</sup>). Additionally, DPM17 grows in the presence of up to 10% NaCl, indicating its halophilic nature. DPM17 was identified as <i>Bacillus</i> <i>baekryungensis</i> based on comparative sequence analysis of the 16S rRNA gene, and neighbor-joining phylogenetic analyses indicated that DPM17 was 96.51% identified to <i>Bacillus</i> sp. DPM17 inoculation substantially improved <i>Abelmoschus esculentus</i> (okra) root length, lateral root count, and dry weight from 7.03 to 9.41 (<i>p</i> = 0.03), 3.2 to 7.2, and 6 to 13 mg (<i>p</i> = 0.032), respectively. The results suggest that DPM17 enhances plant growth and can be exploited to develop efficient formulations for sustainable agriculture and food security in Saudi Arabia.
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