Plant Growth Promoting Rhizobacteria (PGPR): Isolation, Characterization and their multi-stress tolerant efficacy

Abstract

In soils, plant growth promoting rhizobacteria (PGPR) are the most efficacious type of bacteria which help to enhance the plant growth, yield, soil nutrients and also serving as an alternative biofertilizer. Hence, the current investigation targeted on the isolation and assessment of PGPR from iron enriched soils. Total sixteen bacteria were isolated from the rhizosphere soils of Sorghum bicolor, Oryza sativa and Solanum melongena and their PGPR characterization was assessed. All the 16 isolates were cultured under iron stress condition and five isolates were taken for further studies which possess an excellent iron tolerant capability. They were also assessed for salinity tolerance, drought tolerance and various PGPR characterization like production of amylase, catalase, hydrolytic enzyme activity (proteolytic and pectinolytic), ammonia, IAA, gibberellic acid and biofilm formation. Finally, five effective Bacillus strains were identified through 16s rRNA gene amplification. Based on the outcome of the study, all the potential strains of Bacillus sp. showed excellent plant growth promoting (PGP) ability on tested crops.