Phosphate and potassium-solubilizing bacteria effect on the growth of rice

Schematics representation of the interaction between potassium-solubilizing bacteria (KSB) or phosphate-solubilizing bacteria (PSB) and plant root to release potassium (K) and phosphorus (P) in forms that can be absorbed by plant. ▪ [Display omitted] •Pantoea ananatis, Rahnella aquatilis and Enterobacter sp. could release K from mica.•This is first report about R. aquatilisas an effective KSB.•All these KSBs improved the growth of rice in both pot and field experiments, when compared to the control.•These KSBs can be used as effective biofertilizer for eco-friendly rice production systems and also can be worthy of commercial development. The objective of this study was to investigate the ability of three phosphate-solubilizing bacteria (PSB), including Pantoea ananatis (KM977993), Rahnella aquatilis (KM977991) and Enterobacter sp. (KM977992), to release potassium (K) from mica and also to evaluate their effect in promoting the growth of rice (cv. ‘Tarom Hashemi’) plants at an early stage of development. These isolates significantly solubilized K from mica in both solid and liquid medium in vitro. After 25 days of growth in liquid AM medium, K-solubilization (KS) for P. ananatis, Enterobacter sp. and R. aqautillis was 38.9, 33.6 and 15.5μgml−1, respectively. KS of the isolates increased as pH of the culture medium declined (r=−0.83, P