Optimization of media components for production of antimicrobial compound by Brevibacillus brevis EGS9 isolated from mangrove ecosystem

The aim of the present study was to show the efficiency of multi-factorial experimental design to investigate factors affecting the antimicrobial compound production by Brevibacillus brevis EGS9 isolated from mangrove sediment soil. The isolate utilizing different carbon and nitrogen sources showed different growth characteristics. Placket Burmann Design (PBD) showed that glycerol, yeast extracts, calcium carbonate and pH7 have significantly influenced antimicrobial compound production. Response surface methodology with Central Composite Design (CCD) was analysed to optimize these media component for the utmost antimicrobial compound production of Brevibacillus brevis EGS 9. A total of 30 experiments were conducted towards the process of quadratic model and second order polynomial models were recognized to identify the relationship between the selected factor and compound yields. Further, Central Composite Design (CCD) analysis revealed that glycerol (15g/l), yeast extracts (15g/l), calcium carbonate (1.5g/l) and pH (7.0) had significant effect and antimicrobial metabolite production was enhanced by 1.5 fold in antimicrobial activity from 11.80-18.50 zone of inhibition. The integrated statistical tools facilitated rapid identification and combination of key medium parameters for optimization to improve antimicrobial compound production and found a useful way to develop Brevibacillus brevis EGS9 for improved production of antimicrobial compound.