Process for the preparation of an antimicrobial peptide

A process for preparation of a peptide of sequence ID No. 1 having a formula C231H354N66O83, wherein the process comprises the steps of:

• (i) selecting plant Millettia pachycarpa harboring microbial endophytes;
• (ii) isolating endophyte Paenibacillus peoriae with surface sterilization technique;
• (iii) culturing Paenibacillus peoriae on a growth medium at a temperature in a range of 35-40° C. for 5-7 days to obtain cells;
• (iv) harvesting the cells by centrifugation for 10-20 minutes at a speed of 3000-4000 rpm and at a temperature of 4° € 4° C. and obtaining a supernatant;
• (v) filtering the supernatant through a 0.2 μm ultrafiltration membrane to obtain a clarified supernatant;
• (vi) subjecting the clarified supernatant obtained in step (v) with 70% ammonium sulphate precipitation and incubating for a period of 3-5 hours at room temperature to obtain a mixture;
• (vii) centrifuging the mixture obtained in step (vi) at a speed of 4000 rpm for 30-40 minutes at a temperature of 4° C. to collect pellets, followed by dissolving the pellets in distilled water;
• (viii) dialyzing the dissolved pellets obtained in step (vii) against sodium phosphate buffer twice for a period of 12 hours to obtain a solution;
• (ix) purifying the solution obtained in step (viii) using column chromatography with DEAE-Cellulose and eluting with 100-700 mM NaCl followed by dialyses to obtain a dialysate sample;
• (x) analyzing the dialysate sample of step (ix) with RP-HPLC to obtain an antimicrobial peptide (AMP) peak;
• and
• (xi) analyzing the AMP peak with 12% Tricine SDS-PAGE and sequencing with LC-MS.