Growth promotion and biocontrol activity of Nocardiopsis dassonvillei strain YM12: an isolate from coastal agricultural land of Khambhat

Ecological niche of coastal agricultural land of Khambhat, Gujarat (India) has an impact of marine and terrestrial process. Present study explored soil microbial biomass from a unique niche, which can contribute to the sustainable agricultural approach. Total 68 isolates with percent ratio of 42:58 of Actinobacteria:bacteria were isolated from the alkaline soil with pH 8.1. Twenty-eight isolates were identified as cultivable Actinobacteria associated with the order Streptomycetales, Streptosporengiales, micrococcales, Pseudonocardials and it belonged to 14 different genera. All the strains were screened primarily for Plant growth promoting traits like IAA production, ammonia production, phosphate as well as potassium solubilisation, glucanase and chitinase production. Strain YM12 having maximum traits positive for promoting growth and biocontrol activity was further used and characterized. Strain YM12 was identified as Nocardiopsis dassonvillei which showed 262.4 µg ml IAA production, 7.2 µmol ml Ammonia production along with mineral solubilisation capacity (Phosphate—288 ppm, Potassium—48.82 ppm). Apart from having plant growth promoting activity, strain showed inhibition of Fusarium growth which might be due to production of 0.004 μM ml Chitinase and 0.0093 µM ml Glucanase enzyme. Further it was tested for growth promotion of Pearl Millet (Pennisetum glaucum) and showed 20–30% increased growth as compared to control plants.