Exploring the Phosphate Solubilizing Potential and Acid-Alkaline Phosphatase Activity of Two Multitrait Heavy Metal Tolerant Bacterial Strains Isolated from North Gujarat, India

A study was conducted to isolate and characterize phosphate solubilizing bacteria (PSB) from soils of various locations in North Gujarat. total 40 PSB isolates were obtained, exhibiting a index (PSI) ranging 2.11 4.33. Interestingly, among isolates, subset 16 displayed an additional trait potassium solubilization, as evidenced by their (KSI) values falling within the range 2.10 3.10. These screened for tolerance heavy metal stressors, namely CdCl2, HgCl2, Pb(NO3)2, ZnSO4, spanning concentration gradient 0.1 mM 10 mM. Remarkably, tested two, namely, D4 G2, exhibited exceptional resilience against indicated minimum inhibitory (MIC). Specifically, showed MIC 5 mM, 0.2 18 12 respectively, ZnSO4. For corresponding 6 21 11 The bacterial molecularly identified strains Klebsiella pneumoniae PHmD4 (abbreviated D4) Enterobacter chuandaensis PHmG2 G2), based on sequence homology obtained 16S rDNA gene sequencing subsequent BLAST analysis. In Pikovskaya’s broth, K. E. had solubilization 4.30 μ moles mL⁻¹ 3.51 μmoles mL⁻¹, with terminal pH 3.06 4.07. Enzymatic activity assays after 96 hours incubation broth revealed that highest acid phosphatase 21.62 U 21.09 PHmG2. alkaline 5.85 6.38 respectively. tomato seed germination study, both non-bacterized bacterized seeds achieved 100% rate. However, increasing concentrations diminished percentage metal-treated seeds. bacterization ameliorated under cadmium stress but no mitigative effect mercury zinc conditions.