Isolation of phosphate solubilizing endophytic bacteria from Phyllanthus amarus Schum & Thonn: Evaluation of plant growth promotion and antioxidant activity under salt stress

• Endophytic isolates Acinetobacter sp. and Bacillus sp., were isolated from P. amarus.
• Strains were positive for most of plant growth promoting traits and hydrolytic enzyme.
• Isolates under salt stress promoted higher plant growth and P content.
• Plant phenolic content, radical scavenging and antioxidative activity, were improved

In the present study, two salt tolerant endophytic and phosphate solubilizing bacteria ACMS25 and PVMX4 isolated from Phyllanthus amarus are identified as Acinetobacter sp. and Bacillus sp. based on 16s rRNA sequencing. Both the strains were found to be positive for most of plant growth promoting traits evaluated and hydrolytic enzyme studied. Under in vitro conditions at 160 mM NaCl, both the endophytes alone or in combination promoted a higher vigor index, germination (%), plant biomass, P content, plant phenolic content, radical scavenging and antioxidative activity, compared to the standard strain Bacillus megaterium MTCC446 and un-inoculated control.