Functional characterization of endophytic bacteria isolated from feather grass (Chloris virgata Sw.)

Abstract

The objective of this research was to isolate, identify, conduct biochemical characterization, and evaluate the plant growth-promoting (PGP) characteristics of endophytic bacteria obtained from various parts of feather grass collected from waterlogged rice fields. A total of 43 bacterial isolates from roots, rhizome and leaf of Chloris virgata were isolated. They were subjected to biochemical characterization (Catalase, Oxidase, Indole, Methyl red and Vogues Prausker, oxidative fermentation test). The isolates were tested qualitatively and quantitatively for PGP traits including indole acetic acid (>0.2·µg mL−1), gibberellic acid production (> 21.03 µg·mL−1), inorganic phosphate solubilization (PSI), siderophore production (> 26.5 PSU), ammonia production (>120.0 µg·mL−1) and HCN production. The isolates were also subjected to salt (NaCl) and osmotic stress (PEG-6000). Endophytic bacteria were morphologically grouped and selected on the basis of their PGP traits for identification via 16s rRNA sequencing. The identified isolates belonged to two genera namely Bacillus and Glutamicibacter with the former being dominant in the plant. A total of 30 endophytic bacterial isolates identified by 16s rRNA gene sequencing were found to be of Bacillus spp. (25 isolates) and Glutamicibacter spp. (five isolates).