Antibacterial Activity of Tunichrome Released from phallusia nigra Marine Tunicate Obtained from Bushehr Coast

Background: Marine life has long been used for their bioactive compounds. Several amazing compounds with different biological activities have so far been identified in tunicates. The aim of the current study was to evaluate the antimicrobial activity of tunichrome released from phallusia nigra marine tunicates collected from Bushehr province coasts, against four strains of Staphylococcus aureus, Bacillus cereus, Salmonella enterica, and Escherichia coli. Materials and Methods: Thirty samples of phallusia nigra marine tunicates were randomly collected from Nayband Bay in Bushehr province, and then their tunichrome was extracted and lyophilized. The antimicrobial activity (MIC and MBC) of the tunichrome extract was evaluated by agar well diffusion and broth macrodilution methods against four strains of foodborne pathogens. Chemical composition of methanol: chloroform:n-hexane extract of the tunichrome was detected by Gas Chromatography-Mass Spectrometry (GC-MS). Results: According to the results, the tunichrome extract showed significant inhibitory and lethal activities against all four studied bacterial strains. However, its antimicrobial activity was higher against Bacillus cereus and Salmonella enterica. The presence of antimicrobial compounds detected by GC-MS confirmed the results of the antibacterial activity of the tunichrome. Conclusion: According to the results, the tunichrome released from phallusia nigra marine tunicate can be an appropriate marine source of antimicrobial compounds with significant performance against foodborne pathogens. According to the literature, the secondary metabolites in the tunichrome have potential biological and neutraceutical effects which require more laboratory studies.