Impact of Plant Growth Promoting Rhizobacteria Exiguobacterium Acetylicum RGK and Enterobacter Mori RGK1 on Growth Parameters and Phytochemicals of Asparagus Racemosus.

Rhizobacteria that promote plant growth (PGPR) are a wide range of soil bacteria that inhabit the rhizosphere of plants. In the present study, two plant growth-promoting bacterial strains were isolated from the rhizospheric soil of the Asparagus plant, Namely Enterobacter mori RGK1 and Exiguobacterium acetylicum RGK, which can enhance plant growth. It was shown that both of these bacterial strains were able to synthesize exopolysaccharide, hydrogen cyanide (HCN), indole acetic acid and siderophores. These strains fix atmospheric nitrogen, solubilize phosphate, zinc and potassium. Additionally, has shown antibiotic susceptibility to antibiotics such as Amikacin, Netilin, Co-trimaxazole, Streptomycin, Furazolidone, Kanamycin, Nalidixic acid, Nitrofurantoin, Tobramycin, Oxytetracyclin, Chloramphenicol, Gentamycin and their ability to withstand salt concentration (NaCl) up to 5-6%. Treatment of Asparagus plantlets with separate and co-culture of both strains demonstrated a remarkable favorable change in physicochemical properties of soil, growth parameters and phytocompounds of Asparagus as compared to control. They improved the growth metrics of the plant such as shoot height, rhizome biomass, plant biomass as well as phenolic, flavonoid, saponin content and free-radical (DPPH) scavenging ability. As compared to the untreated plants, PGPR-treated plantlets showed higher amounts of secondary metabolites, primarily Diosgenin. The main focus is on the use of multiple microbial strains in a single formulation, an emerging trend in sustainable agriculture.