Isolation and Characterization of a Plant Growth-Promoting Bacterium Acinetobacter sp. SuKIC24 From in vitro-Grown Basilicum polystachyon (L.) Moench

In the present study, a plant growth-promoting bacterium isolated from contaminated in vitro-grown Basilicum polystachyon (L.) Moench, an herbaceous plant, was studied and identified as Acinetobacter strain SuKIC24 based on the 16S rRNA gene sequence analysis. The results revealed that the identified strain exhibited a strong ability to solubilize the phosphate with phosphate solubilization index of 4.0 and produced 387 mu g/ml of soluble phosphate in Pikovskaya media after 7 days of incubation, whereas zinc solubilization efficacy was determined to be 175%. Reversed-phase high-performance liquid chromatography (RP-HPLC) analysis revealed that the bacterium strain produced 77.36 mu g/ml of indole-3-acetic acid. Plant inoculated with the bacterium strain was found to demonstrate a significant increase in height of B. polystachyon as compared to the control plant. The present findings indicated that the identified bacterium strain might act as plant growth-promoting bacterium (PGPB).