الملخص
Aims@#The aim of this study was to evaluate the antibacterial activity of bacteria associated with sea sponge Amphimedon sp. against multi-drug resistant (MDR) bacteria that cause wound infections.@*Methodology and results @#The antibacterial activity was evaluated by the overlay method. Identification of active bacterial symbionts was carried out using the 16S rRNA gene sequence-based method of bacterial identification. The results suggest that one of nine isolates had antibacterial activity against MDR bacteria. Isolate Z9VIII was identified as Bacillus subtilis and demonstrated robust antibacterial activity against bacteria: MRSA (11 mm), MDR-AB (17 mm) and CRPA (12 mm). @*Conclusion, significance and impact of study@#This study concludes that the one of the bacterial species associated with the sea sponge of Amphimedon sp. was B. subtilis, which has the potential as antibacterial agent against MDR bacteria.
الملخص
Aims@#Lactic acid bacteria (LAB) biofilms constitute one of the most remarkable breakthroughs in the field of food biopreservatives and can be employed to prevent foodborne disease. The purposes of this study were to investigate the efficacy of inhibitory LAB biofilms against foodborne pathogens and evaluate their tolerance to acidic pH and bile salts, as well as their physicochemical properties.@*Methodology and results@#Four strains of Lactobacillus brevis biofilms isolated from kimchi showed antipathogenic activity to the bacteria Staphylococcus aureus FNCC 0049 and Escherichia coli FNCC 0091. These biofilms were also tolerant to pH 2.5, 0.3% bile salt and strong adhesion. Two of the four L. brevis biofilms (L. brevis biofilm KA2 and KB1) produced the highest inhibitory activity against both pathogenic bacterial indicators, tolerance to acidic pH and bile salts, and the strongest adhesion. In addition, based on Scanning Electron Microscope-Energy Dispersion X-ray Spectroscopy (SEM-EDS) analysis, both biofilm strains had a smooth surface texture; the cell morphology was rod-shaped and consisted of several elements such as carbon, oxygen and nitrogen, which was built up of extracellular polymeric substances (EPS).@*Conclusion, significance and impact of study@#The presence of EPS as a constituent of LAB biofilms influenced their survival abilities in an acidic pH and bile salt environment. As a result, the characteristics of L. brevis biofilm KA2 and KB1 made them excellent candidates for use as antimicrobial packaging systems in food biopreservative applications.