Antibiosis of Commensal Bacteria Harboring the Gut of Estuarine Water Fish 'Chelon parsia'

Screening of gut flora of the estuarine water fish 'Chelon parsia' for the presence of potential antibiotic producers resulted in finding a new strain Bacillus subtilis PP2. Further investigations focused on the active principle deduced that the molecule is a peptide class of antimicrobial agent with m/z of 1006.66. The culture condition optimization with improved combination and concentration of nitrogen and carbon sources had profound effect on bacterial growth as well as peptide production. In the preliminary stage of drug intervention, the partially characterized peptide antibiotic was found to be a broad-spectrum antifungal agent that can act against a number of fungal pathogens. The efficacy measurement indicated that the minimum inhibitory concentration (MIC) range of the peptide against various fungal pathogens ranges from 8.5 to 14.5 mu g/mL. In terms of antibacterial activity, the molecule exhibits high efficacy, only in the narrow spectrum range. Antibacterial activity was observed against few bacterial pathogens with significantly pleasing MIC range (2.5 to 4.5 mu g/mL) when compared with standard antibacterial drugs. The powerful surfactant property of the molecule opens up extended application into various fields. The novelty of the molecule is under investigation where the unique mass range (m/z 1006.66) of the molecule among the other peptide antibiotics produced by Bacillus subtilis is the key highlight. The findings of the present study suggest that the molecule can be proposed as a lead for the development of a multipurpose antimicrobial agent.

Automated summary

A new strain Bacillus subtilis PP2 was discovered from gut flora of the estuarine water fish, which produces a peptide antimicrobial agent effective against both fungal and bacterial pathogens. The molecule exhibits a unique mass range, showing promising potential as a lead for the development of a multipurpose antimicrobial agent.