Isolation, identification and characterization of halophilic Salinicoccus roseus BMRL-13 and evaluation of its antimicrobial and thrombolytic potential

Background: Halophilic microorganisms thriving in high-saline environments are recognized as a significant source of novel bioactive metabolites. The rise in antimicrobial resistance and the increasing burden of cardiovascular diseases cause health challenges worldwide. Commercially available antimicrobial and thrombolytic drugs have many side effects and high costs. Objectives: To explore halophilic bacteria as a source of bioactive compounds with thrombolytic and antimicrobial potential. Methods: Halophilic Gram-positive bacteria isolated from the salt mine of Khewra, Punjab, Pakistan, were characterized morphologically and biochemically and molecular identification was performed by 16S ribosomal RNA gene sequencing. Antimicrobial activities of extracts were checked against pathogenic bacteria, including Staphylococcus aureus, Bacillus subtilis, Pasteurella multocida and Escherichia coli, as well as Aspergillus niger. The thrombolytic potential of extracts was also investigated. Results: Bacteria showed maximum homology with Salinicoccus roseus strain. The sequence was submitted to GenBank (accession number PQ636913). Bacterial extracts were prepared using methanol (ME), ethyl acetate (EAE) and aqueous layer (AE). EAE showed the highest antibacterial activity against P. multocida with a zone of inhibition (ZOI) of 24.06 ± 0.35 mm. However, ME exhibited the highest antibacterial activity against E. coli (19.20 ± 0.36 mm), S. aureus (16.06 ± 0.25 mm) and B. subtilis (13.46 ± 0.35 mm). No antifungal activity was observed for any extract. Thrombolytic potential was also assessed and EAE (33.72% ± 1.94) represented the highest thrombolytic activity, followed by AE (25% ± 0.81) and ME (16% ± 1.75). Cytotoxicity of extracts was analyzed; EAE exhibited maximum hemolysis of 11.81% ± 0.41. Conclusion: The results suggest that bioactive metabolites from the halophilic bacterium Salinicoccus roseus BMRL-13 strain may be candidates for developing new therapeutic agents for infectious and thrombolytic disorders. All the experiments were carried out in triplicate and results were presented as the mean with standard deviation.