DLSU Senior High School Research Congress Conference Proceedings
Document Type
Paper Presentation
Research Advisor (Last Name, First Name, Middle Initial)
Gurtiza, John Albert D.
Abstract/Executive Summary
Biofilms, which are widespread microbial communities protected by a self-produced matrix, pose a significant threat to human health, industrial processes, and food safety. While synthetic antimicrobials are widely used, concerns about resistance and environmental impact drive the search for natural alternatives. Guyabano (Annona muricata), a tropical fruit known for its antimicrobial properties, shows potential as a natural antibiofilm agent. This study aimed to compare the impact of three different maceration extraction methods (aqueous, ethanolic, and methanolic) on the antibiofilm efficacy of A. muricata leaf extract against Bacillus subtilis biofilm. Each extract was subjected to a 96-well microplate biofilm inhibition assay, measuring optical density (OD) at 600 nm to quantify biofilm formation. Serial dilution and colony-forming unit (CFU) counting were used to assess bacterial viability. Statistical analysis revealed no significant difference among the extraction methods (p = 0.67), indicating that all three methods are similarly effective. The study found that all three extracts demonstrated notable biofilm inhibition, with the highest inhibition observed at a 10⁻⁷dilution for ethanolic extract (89.56%). However, the extracts exhibited inconsistent antibacterial activity, with bacterial colonies too many to count (TMTC) at higher dilutions. These findings suggest that regardless of the method used, the extracts are capable of effectively inhibiting B. subtilis biofilm formation.
Keywords
Annona muricata leaf extract; Bacillus subtilis biofilm formation; aqueous extraction; ethanolic extraction; methanolic extraction