Isolation and Antimicrobial Activity of Halophilic Bacteria Isolated from Saline Soil of Shushtar City, Iran

Background: The rise of multi-drug-resistant bacteria seriously threatens human health. Some microorganisms can produce new antimicrobials that have effects on multidrug-resistant bacteria. On the other hand, halophilic bacteria show promise in producing novel bioactive antimicrobial compounds that could benefit drug development. This study aims to investigate the antimicrobial properties of halophilic bacteria recently isolated in soil samples from Shushtar City, Khuzestan Province, Iran. Methods: In this research, saline soil samples were collected from the salty areas around Shushtar City. The soil sample was then cultured in an enriched culture medium, and in order to isolate the halophilic bacteria, they were cultured in a solid medium. The microorganisms were examined for the production of antimicrobial agents using the agar well diffusion method. Subsequently, the halophilic bacteria were identified through molecular analysis of the 16S rRNA method. The phylogenetic tree was constructed using Mega software through the neighbor-joining method. Results: Twenty-two strains were isolated in this study. Strain E1, identified as Alkalihalobacillus sp, displayed antimicrobial activity against Enterococcus faecalis. The MIC and MBC of the Alkalihalobacillus extracts against Enterococcus faecalis were determined to be 25 µg/mL Conclusion: This research highlights the potential therapeutic and preventive advantages of Alkalihalobacillus sp. extracts as antibacterial agents. This research report, for the first time,reveals that isolated Alkalihalobacillus in Iran has the ability to produce antimicrobial agents.The discovery and isolation of beneficial bacteria from natural sources could have significantimplications for future pharmaceutical and industrial applications.