Isolation and characterization characterisation of salt tolerant and inorganic phosphate solubilizing solubilising bacteria from pomelo cultivated soil of Ben Tre provincethe Mekong River Delta

Abstract

Phosphorus solubilizing solubilising bacteria play an important role in agricultural production. The purpose of this study was conducted to isolate, select, and identify bacteria with inorganic phosphorus solubilizing solubilising activity on Pikovskaya (PVK) medium containing sodium chloride ≥1% from pomelo cultivated soil samples under salt stress condition in Ben Tre province. The results showed that the T2917 and T3602 isolates exhibited showed the highest inorganic phosphorus solubilizing solubilising activity on the PVK medium. The Colony colony of T2917 isolate was round, pale yellow pigmented on the PVK medium, and the cell of this isolate was short rod-shaped, motile, gram-negative staining, and resistant to NaCl 5% level. Meanwhile, the colony of T3602 isolate did not produce pigments, milky colour on the PVK medium, and its cells was spherical, oval, motile, gram-negative staining, and resistant to NaCl 3% level. The PCR reaction was amplified the 16S ribosomal RNA gene of the bacteria with approximately 1,500 base pairs. Phylogenetic analysis of the 16S ribosomal RNA gene indicated that T2917 isolate belongs to genus Pseudomonas genus and that the closest related species is Pseudomonas oryzihabitans; and T3602 isolate was closely related to Burkholderia sp., genus Burkholderia genus.