*2.2. Morphological Characterization of Isolates*

Morphological characteristics of isolates were assessed by scanning electron microscopy (SEM). Bacterial colonies were inoculated in ISP-2 medium and incubated at 28 ± 2 ◦C for 7 days. Cells were centrifuged (Eppendorf, USA) at 8000× *g* for 10 min and pellet was resuspended in 2%–5% gluteraldehyde (Sigma, Burlington, VT, USA) prepared in 0.1M phosphate buffer, pH 7.2. After incubating samples for 30 min, supernatant was discarded and pellet was resuspended in 1% osmium tetraoxide (Sigma, Burlington, VT, USA), incubated for 1 h and centrifuged at 5000 × *g*. To the pellet, sterile water was added and centrifuged twice for 10 min at 5000 × *g*. For dehydration, the pellet was resuspended in 35% ethanol for 10 min, 50% ethanol for 10 min, 75% ethanol for 10 min, 95% ethanol for 10 min, and a final wash with 100% ethanol for 10 min. For SEM analysis, sterilized aluminum stubs and cover slips were inserted into the SCA plates at an angle of about 45 ◦C. The plates with stubs and coverslips were incubated at 37 ◦C for 24 h to check any contamination. After 24 h, isolates were introduced along the line where the surface of the stub met the agar medium and incubated at 28 ± 2 ◦C for 7 days. The stubs were then carefully removed and coated under vacuum, with a film of gold for 25–30 min and viewed on the scanning electron microscope (Zeiss Evo 40 EP, Germany).
