4.1. Media

Luria–Bertani broth (LBB) pH 7.2 (HiMedia, Mumbai, India) was used in all the protocols in the current study. Bacterial dilutions from 18 h LBB cultures grown at 37 °C were carried out in phosphate-buffered saline (PBS; Oxoid, Basingstoke, UK). For performing the plaque assay, ‘soft layer agar’ which was LBB broth in Lambda-buffer [6 mmol L⁻¹ tris pH 7.2; 10 mmol L⁻¹ Mg(SO₄)₂·7H₂O; 50 mg L⁻¹ gelatin (HiMedia)] and supplemented with 4 g L⁻¹ agar (HiMedia) was used. To determine the optimum media, Luria–Bertani agar (LBA), nutrient agar (HiMedia), soybean casein digest agar (HiMedia) and Mueller–Hinton agar (Mast group, Bootle, UK) were used.

All bacteriophages were maintained and diluted in Lambda-buffer [6 mmol L⁻¹ tris pH 7.2; 10 mmol L⁻¹ Mg (SO₄)₂·7H₂O; 50 mg L^-1 gelatin (Oxoid)] and were preserved at 4 °C.