*2.2. Actinobacterial Isolates*

Isolation of the actinobacterial strain was determined by serial dilution method on starch casein agar (Himedia, New Delhi, India) supplemented with nalidixic acid (25 μg/mL) and nystatin (50 μg/mL). The plates were incubated at 28 ◦C for 7 days. After incubation, individual colonies were maintained on ISP-2 slants and stored at 4 ◦C for further use. The ornamentation of the spore chain was analyzed by SEM.

### *2.3. Molecular Identification of Actinobacteria*

Genomic DNA extraction of the strain was done using the phenol-chloroform method. The selected colony was grown in ISP-2 (International Streptomyces Project) broth on the rotary shaker (140 rpm, Hahn-Shin, Bucheon, South Korea) at 28 ◦C, pH 7.2 for 14 days. The cells were harvested by centrifugation at 8000 rpm for 10 min and the pellet was washed twice with normal saline. Washed pellet was suspended in 10 mM Tris-HCl (pH 8, Merck, Burlington, VT, USA) and lysozyme (2.5 mg/Ml, Sigma, Burlington, VT, USA), incubated at 37 ◦C for 1 h and was re-suspended in lysis buffer (50 mM Tris, 10 mM ethylenediaminetetraacetic acid (EDTA, Qualigens Fine Chemicals Pvt. Ltd., San Diego, CA, USA), 1% sodium dodecyl sulfate (SDS, Sigma)) and proteinase K (1 mg/mL, Sigma) and incubated for 1 h at 50 ◦C. 400 μL of phenol (Tris-saturated, Himedia, New Delhi, India) was added and mixed vigorously for 2 min. After centrifugation, the upper aqueous layer was transferred to the fresh tube (Tarsons, Kolkata, India), followed by the addition of CHCl3 (Sigma) and isoamyl alcohol (Merck) (24:1) and centrifuged at 1000 rpm for 15 min (4 ◦C). To the supernatant 50 μL of NaCl (5M) and twice the volume of absolute alcohol (Himedia) was added and kept for overnight incubation. Again, it was centrifuged at 14,000 rpm for 15 min and the pellet was washed with 70% alcohol. Pellet was air dried to remove traces of ethanol (EtOH, Himedia) and was suspended in 30 μL of Tris-EDTA (TE) buffer (Himedia). DNA was analyzed by 1% agarose gel electrophoresis (Bio-Rad, Hercules, CA, USA).

16S rRNA gene amplification was carried out using universal primer set, 27F (5 -AGAGTTTGA TCCTGGCTCAG-3 ) and 1492R (5 -ACGGCTACCTTGTTACGACTT-3 ). The PCR conditions were programmed as follows: Initial denaturation at 95 ◦C for 5 min; followed by 35 cycles at 95 ◦C for 1 min, primer annealing at 54 ◦C for 1 min, extension at 72 ◦C for 1 min. Final extension was done at 72 ◦C for 10 min and was kept for cooling at 10 ◦C. The amplified products were determined at 1.8% agarose gel electrophoresis. The sequence was compared with similar 16S rRNA sequences obtained from BLAST search in National Center for Biotechnology Information (NCBI) database and the phylogenetic tree was constructed by the neighbor joining tree algorithm using MEGA 7.0 software (Mega, Raynham, MA, USA).
