Co-Culturing Bacillus Strains for Enhanced Antimicrobial Activity.

Area of Science:

• Microbiology
• Biotechnology
• Drug Discovery

Background:

• Bacillus probiotic mixtures are recognized for antimicrobial production.
• Need to explore synergistic potential of co-cultured Bacillus strains.
• Understanding mechanisms of combined formulation is crucial.

Purpose of the Study:

• To evaluate the impact of co-culturing Bacillus strains on bacterial growth and antimicrobial production.
• To analyze the chemical profiles and antimicrobial activity of co-cultured Bacillus extracts.
• To investigate the stability and mechanisms of action of produced antimicrobial metabolites.

Main Methods:

• Bacillus strains (BPR-11, BPR-16, BPR-17) were cultured as mono- and multi-cultures.
• Bacterial growth and density were measured via optical density.
• Bioactive extracts were analyzed using LC-MS; antimicrobial activity tested against pathogens.

Main Results:

• Co-cultured strains showed significantly higher bacterial growth (OD 2.67) compared to monocultures.
• Co-culture extract exhibited potent antimicrobial activity (MIC 25 µg/mL) against C. perfringens, E. coli, S. aureus.
• LC-MS revealed increased production of antimicrobial metabolites like surfactin C in co-cultures; surfactin C analogues showed high stability.

Conclusions:

• Multi-strain co-culturing of Bacillus probiotics is a viable strategy for enhanced antimicrobial development.
• Synergistic effects in co-cultures lead to increased growth and potent antimicrobial metabolite production.
• Findings provide insights into developing novel, stable antimicrobial agents from microbial consortia.