Antibacterial compound of Bacillus Amyloliquefaciens and Bacillus Siamensis: screening, characterization, and evaluation

This study was aimed at isolating potential antimicrobial compound (AMC) producing bacteria. AMC produced by a Bacillus species was evaluated further for its antimicrobial potential. Antimicrobial compound-producing bacteria were isolated from the soil of crop fields from the local region of Satana, Nashik (India), and tested against clinical isolates. Both isolates exhibited remarkable antibacterial potential against Gram-positive and Gram-negative clinical isolates. The AMCs of both SYS 1 and SYS 2 exhibited excellent antibacterial activity against Salmonella paratyphi B and Staphylococcus aureus. Both AMC-producing isolates were characterized and identified. Bacillus species SYS 1 and SYS 2 were identified as Bacillus amyloliquefaciens SYS 1 and Bacillus siamensis SYS 2, respectively. The highest antimicrobial activity of AMC produced by Bacillus amyloliquefaciens SYS 1 was exhibited against Salmonella paratyphi B (28 mm), followed by Staphylococcus aureus (26 mm). Bacillus siamensis SYS 2 AMC extracted by the solvent ethyl acetate exerted the highest antimicrobial activity against Salmonella paratyphi B (18 mm), followed by Staphylococcus aureus (16 mm). A partial characterization of the AMC was conducted and evaluated to contain amino acids and proteins. A higher total protein content of 17.9 μg/mL was estimated in the partially purified AMC of Bacillus amyloliquefaciens SYS 1. A detailed evaluation of the structural characteristics of AMC could prove its importance in commercial applications.