AUTHOR=Ismail Amel , Ktari Leila , Ahmed Mehboob , Bolhuis Henk , Boudabbous Abdellatif , Stal Lucas J. , Cretoiu Mariana Silvia , El Bour Monia 

TITLE=Antimicrobial Activities of Bacteria Associated with the Brown Alga Padina pavonica

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.01072

DOI=10.3389/fmicb.2016.01072

ISSN=1664-302X

ABSTRACT=<p>Macroalgae belonging to the genus <italic>Padina</italic> are known to produce antibacterial compounds that may inhibit growth of human- and animal pathogens. Hitherto, it was unclear whether this antibacterial activity is produced by the macroalga itself or by secondary metabolite producing epiphytic bacteria. Here we report antibacterial activities of epiphytic bacteria isolated from <italic>Padina pavonica</italic> (Peacocks tail) located on northern coast of Tunisia. Eighteen isolates were obtained in pure culture and tested for antimicrobial activities. Based on the 16S rRNA gene sequences the isolates were closely related to <italic>Proteobacteria</italic> (12 isolates; 2 Alpha- and 10 <italic>Gammaproteobacteria</italic>), <italic>Firmicutes</italic> (4 isolates) and <italic>Actinobacteria</italic> (2 isolates). The antimicrobial activity was assessed as inhibition of growth of 12 species of pathogenic bacteria (<italic>Aeromonas salmonicida, A. hydrophila, Enterobacter xiangfangensis, Enterococcus faecium, Escherichia coli, Micrococcus</italic> sp.<italic>, Salmonella typhimurium, Staphylococcus aureus, Streptococcus</italic> sp.<italic>, Vibrio alginoliticus, V. proteolyticus, V. vulnificus</italic>) and one pathogenic yeast (<italic>Candida albicans</italic>). Among the <italic>Firmicutes</italic>, isolate P8, which is closely related to <italic>Bacillus pumilus</italic>, displayed the largest spectrum of growth inhibition of the pathogenic bacteria tested. The results emphasize the potential use of <italic>P. pavonica</italic> associated antagonistic bacteria as producers of novel antibacterial compounds.</p>