Antimicrobial Potential and Chemical Characterization of Streptomyces Fulvissimus Isolated from Salt Pan Soils of Nagapattinam District, Tamil Nadu, India

Abstract

Since the emergence of multidrug-resistant (MDR) bacterial pathogens is becoming widespread, there is a need for the discovery of new antimicrobial agents from unexplored ecological niches. Salt pans are extreme environments that contain halophilic and halotolerant Actinomycetes with potential biosynthetic capabilities. In this study, Actinomycetes were isolated from salt pan soils of Nagapattinam District, Tamil Nadu, India, and were screened for antibacterial activity against MDR pathogens. Primary and secondary screening identified a potent isolate, H5, which showed broad-spectrum antibacterial activity. Morphological, physiological, and biochemical characterization suggested that the isolate belonged to the genus Streptomyces. 16S rRNA gene sequencing confirmed the isolate as Streptomyces fulvissimus. The ethyl acetate crude extract of the H5 strain showed maximum antibacterial activity against Escherichia coli, Enterococcus faecalis, and Pseudomonas aeruginosa. Gas chromatography–mass spectrometry (GC–MS) analysis revealed the presence of several bioactive compounds, including N-hexadecanoic acid, oleic acid, squalene, and purine derivatives. Fourier-transform infrared (FT-IR) spectroscopy confirmed the presence of functional groups linked to antimicrobial activity. The results suggest that Streptomyces fulvissimus isolated from salt pan soils could be a potential source of bioactive secondary metabolites that can be exploited in the treatment of MDR bacterial infections.