Antimicrobial Activity and Metabolic Profile of Bacteria from the Maros Pangkep Karst Region

Karst ecosystems are recognized as distinctive and extreme natural environments. Nevertheless, they continue to harbor a high degree of microbial diversity, including cave bacteria that can produce antimicrobial secondary metabolites. The rise in antibiotic-resistant cases, driven by the improper use of antibiotics, has created an urgent need to explore new antimicrobial compounds derived from natural sources. This study aimed to isolate soil bacteria from several caves in the Maros-Pangkep Karst Area. This study evaluated the identification of bacteria and their potential to inhibit pathogenic bacteria. Isolates were obtained from three different locations, including Leang Kassi, Leang Jarie, and Leang Ulu Wae. The results showed that the isolates from Leang Ulu Wae exhibited growth inhibition against Staphylococcus aureus and Escherichia coli in agar diffusion assays. The characterization of metabolite compounds was performed using Fourier-transform infrared (FTIR) spectroscopy and gas chromatography-mass spectrometry (GC-MS) analysis, which tentatively revealed several putative secondary metabolites. However, owing to the absence of procedural blanks (solvent-only and uninoculated medium controls), these tentative compound assignments should be interpreted cautiously, as potential laboratory- or media-derived contaminants cannot be fully excluded. Additionally, molecular identification using 16S rRNA indicated that the bacteria in the Leang Ulu Wae isolate belonged to the genus Exiguobacterium. This finding highlights the potential of cave bacteria as a source of novel bioactive compounds. These compounds can be used to develop novel antimicrobial agents.